A Two-step Sequential Extraction for Analyzing Har

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颗粒磷形态四大分析方法

颗粒磷形态四大分析方法研究颗粒物或沉积物中磷的形态的一个非常重要的目的之一是定量生物颗粒可利用磷，不少研究结果[1-4]指出，悬浮物或沉积物中非磷灰石无机磷为潜在的生物可利用形态，这部分磷在总磷中的含量低者约为10%,高者可达80%.颗粒态磷的形态多种多样，包括不稳定或弱结合态P、水合铁氧化结合P、Ca结合P、有机P等。

分离和定量颗粒物和沉积物中各种P结合项最理想的方法是化学试剂提取法，X-射线衍射要求样品中P含量〉1%wt,而化学试剂提取法可测至0.005%wtP，且精密度可达到4%.试剂提取法又分为选择性化学试剂提取法和连续提取法。

在研究中多为连续提取法。

Chang and Jackson在1957年，Hieltjes-Lijklema在1980年, Psnner在1984年, Daessle LW在1995年, Ruttenberg在1992年, Jensen在1993年和1998年, 分别提出了不同的分析颗粒态磷的方法,其中很多是在前人基础上对细节的改进。

归纳总结一下大体可以分为Hieltjes-Lijklema（1980）方法，Ruttenberg（1992）方法或称SEDEX方法、Golterman（1996）方法或称EDTA方法和SMT方法（1998）四大类，并总结了四种方法的优缺点。

一、Hieltjes-Lijklema（1980）方法：4步曾经被广泛应用的四步连续提取法：对50mg颗粒物进行提取,以25ml 2M NH4Cl对50mg颗粒物进行提取，提取出弱结合态磷（PH=7），以25mL0.1N NaOH 提取，提取出铁及铝结合磷；以25 mL 0.5MHCl提取出钙、镁结合态磷；以K2S2O8/H2SO4对上述提取后的残渣进行硝化，提取出了残余态有机磷；酸及碱提取液中会含有部分的有机磷，此部分有机磷可通过硝化成为无机磷的方法进行测量，优点：方法对于钙质沉积物中磷的形态是一个有效的技术，缺点：然而前两步的提取解释必须注意，但测量结果重现性很差。

取样分离法的英文缩写

取样分离法的英文缩写The Abbreviation of Sampling Separation MethodIntroduction:Sampling separation is a crucial process in various scientific fields, aiming to isolate and extract specific components from a mixture for further analysis or application. In order to simplify its usage, an abbreviation, also known as an acronym or initialism, is often assigned to represent the sampling separation method. This article explores the significance of abbreviations for sampling separation methods in the English language.Abbreviations in Sampling Separation Methods:Abbreviations play a vital role in simplifying complex terminologies, especially in scientific research. By condensing a long and technical name into a shorter form, abbreviations make it easier for researchers, professionals, and even general readers to refer to a particular sampling separation method efficiently. These abbreviations are widely accepted and recognized across the scientific community and help in creating a standardized language for communication.Importance of Abbreviations:1. Enhanced Communication:Abbreviations act as effective communication tools, as they facilitate easy and precise exchange of information between researchers and experts. The use of abbreviations enables efficient and concise communication in scientific journals, research papers, and conferences. Additionally,abbreviations assist in the dissemination of knowledge, allowing researchers to present their work without the cumbersome repetition of lengthy methodologies.2. Time-Saving:The utilization of abbreviations saves valuable time for both the writer and the reader. Instead of repeatedly writing the complete name of a sampling separation method, researchers can use the respective abbreviation, reducing the overall length of the text. This time-saving benefit enables authors to focus on explaining the nuances of the method rather than wasting words on repetitive instances of its name.3. Standardization:Standardization plays a pivotal role in establishing a common platform for sharing and understanding scientific concepts. Abbreviations ensure uniformity and consistency in scientific literature and research, as the same abbreviation is used for a specific sampling separation method by different scientists and researchers. This standardization eliminates confusion and ambiguity that may arise due to variations in the nomenclature of different techniques.Examples of Abbreviations:1. Liquid-Liquid Extraction (LLE): LLE is a widely used method for extracting a compound of interest from a liquid mixture by partitioning it between two immiscible liquids.2. Solid Phase Extraction (SPE): SPE is a technique that involves the use of a solid adsorbent to extract and isolate specific analytes from a sample matrix.3. Gas Chromatography (GC): GC is an analytical method used to separate and analyze volatile compounds in a gaseous mixture.4. High-Performance Liquid Chromatography (HPLC): HPLC is a technique that utilizes high-pressure pumps to separate and identify components in a liquid mixture.Conclusion:Sampling separation methods are pivotal in various scientific fields for accurate analysis and understanding of mixtures. Abbreviations associated with these methods have become essential tools for efficient communication, time-saving writing practices, and standardization of terminologies in scientific literature. It is crucial for scientists and researchers to utilize these abbreviations accurately and consistently, ensuring effective knowledge dissemination across the scientific community.。

马齿苋中抗炎活性物质的提取、分离及结构鉴定

马齿苋中抗炎活性物质的提取、分离及结构鉴定张会敏1，邢岩2，仇润慷1，张丽梅2，倪贺3，赵雷1*（1.华南农业大学食品学院，广东广州 510642）（2.国珍健康科技（北京）有限公司，北京 100000)（3.华南师范大学生命科学学院，广东广州 510640）摘要：以活性物质示踪为导向，建立脂多糖诱导的RAW264.7巨噬细胞炎症模型对马齿苋中的抗炎物质进行跟踪，采用柱层析提取法、硅胶柱色谱分离法、制备液相色谱法及气相色谱-质谱联用技术对抗炎物质进行提取分离和结构鉴定。

结果表明，石油醚-乙醇、无水乙醇和纯水溶剂依次对马齿苋样品进行提取，三种粗提物将细胞中一氧化氮（Nitric Oxide，NO）的分泌量分别减少至33.13、25.83和20.53 μmol/L，其中石油醚相粗提物的抑制效果最强（P<0.05）。

对石油醚相进一步分离得到四个组分，Fr.1、Fr.2和Fr.3组分具有较强的抗炎效果，但Fr.1和Fr.2组分含有潜在的毒性成分，选择Fr.3组分继续分离。

Fr.3组分经硅胶柱分离得到三个组分，Fr.3.1组分表现出最强的抑制NO的分泌量效果（11.80 μmol/L）。

经制备液相色谱进一步纯化及气质分析，确定Fr.3.1组分的主要成分为硬脂酸（47.09%）、邻苯二甲酸二(2-乙基己)酯（13.21%）和其他成分。

该研究建立了一种从马齿苋中分离纯化出抗炎物质方法，为马齿苋的开发利用提供理论参考。

关键词：马齿苋；抗炎活性；提取分离；鉴定文章编号：1673-9078(2024)03-191-199 DOI: 10.13982/j.mfst.1673-9078.2024.3.0324Extraction, Separation and Structural Identification of Anti-inflammatory Active Substances from Purslane (Portulaca oleracea L.)ZHANG Huimin1, XING Y an2, QIU Runkang1, ZHAGN Limei2, NI He3, ZHAO Lei1*(1.College of Food Science, South China Agricultural University, Guangzhou 510642, China)(2.Guozhen Health Technology (Beijing) Co. Ltd., Beijing 100000, China)(3.College of Life Sciences, South China Normal University, Guangzhou 510640, China)Abstract: To track the anti-inflammatory substances in purslane, the lipopolysaccharide-induced RAW264.7 macrophage inflammation model was established, which was guided by the tracer of active substances. The extraction, separation and structural identification of anti-inflammatory substances in purslane were performed by column chromatography (for extraction), silica gel column chromatography (for separation), and preparative high performance liquid chromatography and gas chromatography-mass spectrometry (for analyses). The results showed that the three crude extracts obtained from purslane through sequential extractions with petroleum ether-ethanol, anhydrous ethanol and pure引文格式：张会敏,邢岩,仇润慷,等.马齿苋中抗炎活性物质的提取、分离及结构鉴定[J] .现代食品科技,2024,40(3):191-199.ZHANG Huimin, XING Yan, QIU Runkang, et al. Extraction, separation and structural identification of anti-inflammatory active substances from purslane (Portulaca oleracea L.) [J] . Modern Food Science and Technology, 2024, 40(3): 191-199.收稿日期：2023-03-16基金项目：国家自然科学基金资助项目（31771980）；广东省自然科学基金（2023A1515012599）作者简介：张会敏（1996-），女，硕士研究生，研究方向：活性物质分离提取，E-mail：；共同第一作者：邢岩（1981-），女，博士，助理研究员，研究方向：抗氧化与抗衰老，E-mail：通讯作者：赵雷（1982-），男，博士，教授，研究方向：天然产物绿色修饰及热带水果加工，E-mail：191water solvents reduced the secretion of nitric oxide (NO) in the cells to 33.13, 25.83 and 20.53 μmol/L, respectively, with the crude petroleum ether extract exhibiting the strongest inhibitory effect (P<0.05). The petroleum ether phase was further separated into four fractions, with the Fr.1, Fr.2 and Fr.3 fractions had stronger anti-inflammatory effects, though the Fr.1 and Fr.2 fractions contained potential toxic components. Therefore, the Fr.3 fraction was selected for further separation. The Fr.3 fraction was separated through a silica gel column to obtain three fractions. The Fr.3.1 subfraction exhibited the strongest inhibitory effect against the NO secretion (11.80 μmol/L). The Fr.3.1 subfraction was further purified by the preparative liquid chromatography and GC-MS analysis, and the main components of the Fr.3.1 subfraction were identified as stearic acid (47.09%), di(2-ethylhexyl)phthalate (13.21%) and other components. This study established a method for separating and purifying anti-inflammatory substances from purslane, and provides a theoretical reference for the development and utilization of purslane.Key words: Portulaca oleracea L.; anti-inflammatory activity; extraction and isolation; identification炎症是机体受到外部刺激时做出的一种保护性生理反应，能够及时清除体内受损或死亡的细胞，帮助机体恢复内部平衡[1] 。

云南临沧勐托褐煤中微量元素地球化学

云南临沧勐托褐煤中微量元素地球化学为确定勐托褐煤中微量元素的地球化学特征，在云南省临沧市镇勐托村小煤窑井口共采集11个褐煤样品，采用逐级化学提取和ICP-MS的方法对样品中微量元素的含量进行了测试，结果表明：勐托煤样中Zn、Sr、Li、V、Cr、Cu、Zn、Sr、Sb、Pb元素含量变化范围较大。

与中国煤相比，勐托褐煤中Sb显著富集，Be、As、Cd、Pb稍富集。

与世界褐煤相比，勐托褐煤中Sb显著富集，Be 和Pb富集，Li、V、Cu、Cd稍富集。

勐托褐煤中Li、Be、V、Cr、Cu、Zn、As、Sb、Pb元素含量较高，主要与酸性花岗岩的陆源碎屑供应有关。

标签：勐托；逐级化学提取；微量元素；地球化学1 引言临沧市位于云南省西部。

临沧市分为勐托、博尚、那招三大片区，其中，勐托距大寨和中寨约20 km。

临沧锗矿位于云南西部临沧境内以印支期花岗岩为基底的帮卖含煤碎屑岩盆地中，是我国迄今为止探明的具经济开采价值的超大煤型锗矿床。

其中以临沧的大寨与中寨的锗矿储量最大，约1600t[1]。

本文通过逐级化学提取和ICP-MS等方法探讨与大寨和中寨毗邻的勐托新近系褐煤中微量元素的地球化学特征。

2 样品采集与测试为确定勐托褐煤中微量元素的地球化学特征，在云南省临沧市临翔区博尚镇勐托村小煤窑井口共采集11个褐煤样品，装入聚乙烯袋中密封。

样品风干后，破碎成小块，然后经固体样品粉碎机粉碎，后用玛瑙研磨过200目筛，缩分，贮存于棕色广口瓶中备用[2]。

在安徽理工大学完成了逐级化学提取实验验和使用ICP-MS对煤样中的微量元素进行测试。

3 实验步骤及测试结果3.1 逐级化学提取本实验在总结前人研究的基础上[3-5]，首先采用低温灰化的手段，随后在煤灰中加入5%稀硝酸，尝试在提取硅酸盐结合态之前，分离并获取有机结合态元素含量信息。

本次逐级提取实验选取了7个煤样分别为：Mt1、Mt3、Mt4、Mt5、Mt6、Mt9、Mt10。

实验过程中，每个煤层选一个平行样，分别选择Mt6、Mt9、Mt10。

基于两步法的钙钛矿薄膜制备以及其在低温钙钛矿电池的应用

摘要基于两步法的钙钛矿薄膜制备以及其在低温钙钛矿电池的应用近年来，受能源危机及环境问题的影响，人们一直在寻找一种能够替代传统化石能源方法。

其中太阳能电池以低成本及可再生的优势吸引了越来越多人的注意。

在过去的五年当中，钙钛矿太阳能电池（PSC）效率飙升，成为太阳能电池领域里冉冉升起的一颗新星。

虽然钙钛矿电池器件效率一直在上升，但是依然存在一些问题制约着钙钛矿太阳能电池的发展, 例如:1．在平面结构钙钛矿太阳能电池中，理想的钙钛矿层成为获得高能量转换效率的必要条件之一。

人们发现在CH3NH3PbI3中存在适量的碘化铅晶体能够钝化钙钛矿薄膜晶界，抑制电子空穴的复合，提升短路电流。

两步顺序沉积法已经广泛用于在钙钛矿太阳能电池中。

这种方法将PbI2前驱体薄膜浸渍到碘化甲胺（CH3NH3I，MAI）中制备CH3NH3PbI3活性层。

通过该方法制备的PSC的光伏性能的差异总是被归因于不同浸渍时间将会引起PbI2完全/不完全转化为CH3NH3PbI3。

2．无机金属氧化物电子传输层被广泛地用于钙钛矿太阳能电池中。

大多数无机电子传输层需要高温以形成导电性良好和无缺陷的薄膜。

而这些方法将会限制其在柔性器件中的使用以及将来商业化的应用。

因此，如何得到一种可低温柔性制备的电子传输层成为钙钛矿太阳能电池领域里一项重要的问题之一。

针对以上两个问题我们提出两种解决方案：1．为了解决第一个问题，我们采用溶剂蒸汽退火（SVA）方法制备大晶粒尺寸的PbI2晶体，以制备得到高质量的钙钛矿薄膜。

使用该方法，发现在CH3NH3I溶液中增加的PbI2浸渍时间会降低得到的PSC的能量转换效率，而钙钛矿膜中PbI2 / CH3NH3PbI3的含量并没有明显的变化。

我们通过紫外-可见光吸收，X射线衍射，傅里叶变换红外光谱（FT-IR）和扫描电子显微镜的测试探究了这种变化的来源。

我们将这种光伏性能的异常减少是因为CH3NH3PbI3壳层对PbI2核的插层/脱嵌。

牡丹籽粕中黄酮类化合物的提取工艺优化及膜法分离纯化

邹平，徐莹，陈文涛，等. 牡丹籽粕中黄酮类化合物的提取工艺优化及膜法分离纯化[J]. 食品工业科技，2023，44（18）：258−267.doi: 10.13386/j.issn1002-0306.2022100241ZOU Ping, XU Ying, CHEN Wentao, et al. Optimization of Extraction Process and Purification of Flavonoids from Peony Seed Meal by Membrane Method[J]. Science and Technology of Food Industry, 2023, 44(18): 258−267. (in Chinese with English abstract). doi:10.13386/j.issn1002-0306.2022100241· 工艺技术 ·牡丹籽粕中黄酮类化合物的提取工艺优化及膜法分离纯化邹　平，徐　莹，陈文涛，张迎阳，徐　荣*（常州大学石油化工学院，江苏常州 213164）摘　要：本研究采用微滤-纳滤二级膜分离的方法对牡丹籽粕中的黄酮类化合物进行分离提纯。

通过单因素实验研究料液比、提取温度、乙醇体积分数和提取时间对总黄酮提取量的影响，在单因素的基础上采用响应面法对提取工艺进行优化及验证。

选用聚偏二氟乙烯（PVDF ）、聚醚砜（PES ）、聚四氟乙烯（PTFE ）、聚丙烯（PP ）、混合纤维素（MCE ）、聚丙烯腈（PAN ）、水系醋酸纤维（CA ）和聚酰胺（PA ）8种材料微滤膜对牡丹籽粕黄酮类化合物（PSMF ）提取液进行初级分离。

纳滤膜为实验室自制的有机硅/PA 复合膜。

结果表明，PSMF 最佳的提取条件为料液比1:15 g/mL ，提取温度50 ℃，乙醇体积分数为70%，提取时间为30 min ，PSMF 提取量为（240.28±2.25）μg/mL 。

米氏凯伦藻细胞表面膜蛋白质组及其对温度变化的响应研究

米氏凯伦藻细胞表面膜蛋白质组及其对温度变化的响应研究王坤;王沛;张浩;张树峰;王大志【摘要】米氏凯伦藻(Karenia mikimotoi)近年在我国福建、浙江和广东沿海经常形成赤潮,其赤潮不仅影响到海洋生态系统的稳定,也严重威胁到水产养殖以及人类生命健康安全.本论文以米氏凯伦藻为研究对象,建立了米氏凯伦藻细胞表面膜蛋白质荧光标记技术和细胞膜蛋白质提取方法,运用荧光差异凝胶电泳技术(2-D DIGE)对膜蛋白质进行了分析,并研究了米氏凯伦藻的膜蛋白质组及其对环境温度变动的响应.实验共鉴定到44个细胞表面膜蛋白,其中有效注释27个,主要为转运蛋白、HSP70蛋白家族和捕光蛋白等.米氏凯伦藻在20℃条件下的细胞生长和光合作用要明显好于16℃和12℃,但16℃和12℃条件下的差别不大,表明低温限制了米氏凯伦藻的生长.当米氏凯伦藻从12℃快速转移至16℃和20℃时,藻细胞密度和光合作用效率短时间迅速降低,但细胞很快即适应温度变化.细胞膜上的转运蛋白和光合作用蛋白在其适应温度变化中起着重要作用.【期刊名称】《海洋与湖沼》【年(卷),期】2019(050)003【总页数】12页(P652-663)【关键词】米氏凯伦藻;温度;膜蛋白质;蛋白质组;差异荧光凝胶电泳技术【作者】王坤;王沛;张浩;张树峰;王大志【作者单位】厦门大学近海海洋环境科学国家重点实验室厦门361102;厦门大学近海海洋环境科学国家重点实验室厦门361102;厦门大学近海海洋环境科学国家重点实验室厦门361102;厦门大学近海海洋环境科学国家重点实验室厦门361102;厦门大学近海海洋环境科学国家重点实验室厦门361102;中国科学院海洋生态与环境科学重点实验室青岛266071【正文语种】中文【中图分类】Q946;Q948.885.3;X55米氏凯伦藻(Karenia mikimotoi Hansen)是一种单细胞浮游植物，属于裸甲藻目，可以产生鱼毒素和溶血性毒素，近年来常在我国近岸尤其是浙江、福建和广东沿海形成藻华，给渔业养殖造成了巨大的损失。

翻译

中国石油大学（华东）本科毕业设计（论文）外文翻译学生姓名：姜华学号：06083201专业班级：软件工程2006级2班指导教师：梁玉环2010年6月10日Database ManagementDatabase (sometimes spelled database) is also called an electronic database, referring to any collections of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are structured to facilitate the storage, retrieval modification and deletion of data in conjunction with various data-processing operations. Database can be stored on magnetic disk or tape, optical disk, or some other secondary storage device.A database consists of a file or a set of files. The information in the these files may be broken down into records, each of which consists of one or more fields are the basic units of data storage, and each field typically contains information pertaining to one aspect or attribute of the entity described by the database. Using keywords and various sorting commands, users can rapidly search, rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregates of data.Database records and files must be organized to allow retrieval of the information. Early system were arranged sequentially (i.e., alphabetically, numerically, or chronologically); the development of direct-access storage devices made possible random access to data via indexes. Queries are the main way users retrieve database information. Typically the user provides a string of characters, and the computer searches the database for a corresponding sequence and provides the source materials in which those characters appear.A user can request, for example, all records in which the content of the field for a person’s last name is the word Smith.The many users of a large database must be able to manipulate the information within it quickly at any given time. Moreover, large business and other organizations tend to build up many independent files containing related and even overlapping data, and their data, processing activities often require the linking of data from several files. Several different types of database management systems have been developed to support these requirements: flat, hierarchical, network, relational, and object-oriented.In flat databases, records are organized according to a simple list of entities; many simple databases for personal computers are flat in structure. The records in hierarchical databases are organized in a treelike structure, with each level of records branching off into a set of smaller categories. Unlike hierarchical databases, which provide single links between sets of records at different levels, network databases create multiple linkages between sets by placing links, or pointers, to one set of records in another; the speed and versatility of network databases have led to their wide use in business. Relational databases are used where associations among files or records cannot be expressed by links; a simple flat list becomes one table, or “relation”, and multiple relations can be mathematically as sociated toyield desired information. Object-oriented databases store and manipulate more complex data structures, called “objects”, which are organized into hierarchical classes that may inherit properties from classes higher in the chain; this database structure is the most flexible and adaptable.The information in many databases consists of natural-language texts of documents; number-oriented database primarily contain information such as statistics, tables, financial data, and raw scientific and technical data. Small databases can be maintained on personal-computer systems and may be used by individuals at home. These and larger databases have become increasingly important in business life. Typical commercial applications include airline reservations, production management, medical records in hospitals, and legal records of insurance companies. The largest databases are usually maintained by governmental agencies, business organizations, and universities. These databases may contain texts of such materials as catalogs of various kinds. Reference databases contain bibliographies or indexes that serve as guides to the location of information in books, periodicals, and other published literature. Thousands of these publicly accessible databases now exist, covering topics ranging from law, medicine, and engineering to news and current events, games, classified advertisements, and instructional courses. Professionals such as scientists, doctors, lawyers, financial analysts, stockbrokers, and researchers of all types increasingly rely on these databases for quick, selective access to large volumes of information.DBMS Structuring TechniquesSequential, direct, and other file processing approaches are used to organize and structure data in single files. But a DBMS is able to integrate data elements from several files to answer specific user inquiries for information. That is, the DBMS is able to structure and tie together the logically related data from several large files.Logical Structures. Identifying these logical relationships is a job of the data administrator. A data definition language is used for this purpose. The DBMS may then employ one of the following logical structuring techniques during storage access, and retrieval operations.List structures. In this logical approach, records are linked together by the use of pointers. A pointer is a data item in one record that identifies the storage location of another logically related record. Records in a customer master file, for example, will contain the name and address of each customer, and each record in this file is identified by an account number. During an accounting period, a customer may buy a number of items on different days. Thus, the company may maintain an invoice file to reflect these transactions. A list structure could be used in this situation to show the unpaid invoices at any given time. Each record in the customer in the invoice file. This invoice record, in turn, would be linked to later invoices for the customer. The last invoice in the chain would be identified by the useof a special character as a pointer.Hierarchical (tree) structures. In this logical approach, data units are structured in multiple levels that graphically resemble an “upside down” tree with the root at the top and the branches formed below. There’s a superior-subordinate relationship in a hierarchical (tree) structure. Below the single-root data component are subordinate elements or nodes, each of which, in turn, “own” one or more other elements (or none). Each element or branch in this structure below the root has only a single owner. Thus, a customer owns an invoice, and the invoice has subordinate items. The branches in a tree structure are not connected.Network Structures. Unlike the tree approach, which does not permit the connection of branches, the network structure permits the connection of the nodes in a multidirectional manner. Thus, each node may have several owners and may, in turn, own any number of other data units. Data management software permits the extraction of the needed information from such a structure by beginning with any record in a file.Relational structures. A relational structure is made up of many tables. The data are stored in the form of “relations” in these tables. For example, relation t ables could be established to link a college course with the instructor of the course, and with the location of the class.To find the name of the instructor and the location of the English class, the course/instructor relation is searched to get the name (“Fitt”), and the course/location relation is a relatively new database structuring approach that’s expected to be widely implemented in the future.Physical Structures. People visualize or structure data in logical ways for their own purposes. Thus, records R1 and R2 may always be logically linked and processed in sequence in one particular application. However, in a computer system it’s quite possible that these records that are logically contiguous in one application are not physically stored together. Rather, the physical structure of the records in media and hardware may depend not only on the I/O and storage devices and techniques used, but also on the different logical relationships that users may assign to the data found in R1and R2. For example, R1 and R2 may be records of credit customers who have shipments send to the same block in the same city every 2 weeks. From the shipping department manager’s perspective, then, R1 and R2 are sequential entries on a geographically organized shipping report. But in the A/R application, the customers represented by R1 and R2 may be identified, and their accounts may be processed, according to their account numbers which are widely separated. In short, then, the physical location of the stored records in many computer-based information systems is invisible to users.Database Management Features of OracleOracle includes many features that make the database easier to manage. We’ve divided the discussion in this section into three categories: Oracle Enterprise Manager, add-on packs,backup and recovery.1. Oracle Enterprise ManagerAs part of every Database Server, Oracle provides the Oracle Enterprise Manager (EM), a database management tool framework with a graphical interface used to manage database users, instances, and features (such as replication) that can provide additional information about the Oracle environment.Prior to the Oracle8i database, the EM software had to be installed on Windows 95/98 or NT-based systems and each repository could be accessed by only a single database manager at a time. Now you can use EM from a browser or load it onto Windows 95/98/2000 or NT-based systems. Multiple database administrators can access the EM repository at the same time. In the EM repository for Oracle9i, the super administrator can define services that should be displayed on other administrators’ consoles, and management regions can be set up.2. Add-on packsSeveral optional add-on packs are available for Oracle, as described in the following sections. In addition to these database-management packs, management packs are available for Oracle Applications and for SAP R/3.(1)standard Management PackThe Standard Management Pack for Oracle provides tools for the management of small Oracle databases (e.g., Oracle Server/Standard Edition). Features include support for performance monitoring of database contention, I/O, load, memory use and instance metrics, session analysis, index tuning, and change investigation and tracking.(2)Diagnostics PackYou can use the Diagnostic Pack to monitor, diagnose, and maintain the health of Enterprise Edition databases, operating systems, and applications. With both historical and real-time analysis, you can automatically avoid problems before they occur. The pack also provides capacity planning features that help you plan and track future system-resource requirements.(3)Tuning PackWith the Tuning Pack, you can optimise system performance by identifying and tuning Enterprise Edition databases and application bottlenecks such as inefficient SQL, poor data design, and the improper use of system resources. The pack can proactively discover tuning opportunities and automatically generate the analysis and required changes to tune the systems.(4)Change Management PackThe Change Management Pack helps eliminate errors and loss of data when upgrading Enterprise Edition databases to support new applications. It impact and complex dependencies associated with application changes and automatically perform databaseupgrades. Users can initiate changes with easy-to-use wizards that teach the systematic steps necessary to upgrade.(5)AvailabilityOracle Enterprise Manager can be used for managing Oracle Standard Edition and/or Enterprise Edition. Additional functionality is provided by separate Diagnostics, Tuning, and Change Management Packs.3. Backup and RecoveryAs every database administrator knows, backing up a database is a rather mundane but necessary task. An improper backup makes recovery difficult, if not impossible. Unfortunately, people often realize the extreme importance of this everyday task only when it is too late –usually after losing business-critical data due to a failure of a related system.The following sections describe some products and techniques for performing database backup operations.(1)Recovery ManagerTypical backups include complete database backups (the most common type), database backups, control file backups, and recovery of the database. Previously, Oracle’s Enterprise Backup Utility (EBU) provided a similar solution on some platforms. However, RMAN, with its Recovery Catalog stored in an Oracle database, provides a much more complete solution. RMAN can automatically locate, back up, restore, and recover databases, control files, and archived redo logs. RMAN for Oracle9i can restart backups and restores and implement recovery window policies when backups expire. The Oracle Enterprise Manager Backup Manager provides a GUI-based interface to RMAN.(2)Incremental backup and recoveryRMAN can perform incremental backups of Enterprise Edition databases. Incremental backups back up only the blocks modified since the last backup of a datafile, tablespace, or database; thus, they’re smaller and faster than complete backups. RMAN can also perform point-in-time recovery, which allows the recovery of data until just prior to a undesirable event.(3)Legato Storage ManagerVarious media-management software vendors support RMAN. Oracle bundles Legato Storage Manager with Oracle to provide media-management services, including the tracking of tape volumes, for up to four devices. RMAN interfaces automatically with the media-management software to request the mounting of tapes as needed for backup and recovery operations.(4)AvailabilityWhile basic recovery facilities are available for both Oracle Standard Edition and Enterprise Edition, incremental backups have typically been limited to Enterprise Edition. Choosing between Oracle and SQL ServerI have to decide between using the Oracle database and WebDB vs. Microsoft SQL Server with Visual Studio. This choice will guide our future Web projects. What are the strong points of each of these combinations and what are the negatives?Lori: Making your decision will depend on what you already have. For instance, if you want to implement a Web-based database application and you are a Windows-only shop, SQL Server and the Visual Studio package would be fine. But the Oracle solution would be better with mixed platforms.There are other things to consider, such as what extras you get and what skills are required. WebDB is a content management and development tool that can be used by content creators, database administrators, and developers without any programming experience. WebDB is a browser-based tool that helps ease content creation and provides monitoring and maintenance tools. This is a good solution for organizations already using Oracle. Oracle also scales better than SQL Server, but you will need to have a competent Oracle administrator on hand.The SQL Sever/Visual Studio approach is more difficult to use and requires an experienced object-oriented programmer or some extensive training. However, you do get a fistful of development tools with Visual Studio: Visual Basic, Visual C++, and Visual InterDev for only $1,619. Plus, you will have to add the cost of the SQL Server, which will run you $1,999 for 10 clients or $3,999 for 25 clients-a less expensive solution than Oracle’s.Oracle also has a package solution that starts at $6,767, depending on the platform selected. The suite includes not only WebDB and Oracle8i but also other tools for development such as the Oracle application server, JDeveloper, and Workplace Templates, and the suite runs on more platforms than the Microsoft solution does. This can be a good solution if you are a start-up or a small to midsize business. Buying these tools in a package is less costly than purchasing them individually.Much depends on your skill level, hardware resources, and budget. I hope this helps in your decision-making.Brooks: I totally agree that this decision depends in large part on what infrastructure and expertise you already have. If the decision is close, you need to figure out who’s going to be doing the work and what your priorities are.These two products have different approaches, and they reflect the different personalities of the two vendors. In general, Oracle products are designed for very professional development efforts by top-notch programmers and project leaders. The learning period is fairly long, and the solution is pricey; but if you stick it out you will ultimately have greater scalability and greater reliability.If your project has tight deadlines and you don’t have the time and/or money to hire a team of very expensive, very experienced developers, you may find that the Oracle solutioni s an easy way to get yourself in trouble. There’s nothing worse than a poorly developed Oracle application.What Microsoft offers is a solution that’s aimed at rapid development and low-cost implementation. The tools are cheaper, the servers you’ll run it on are cheaper, and the developers you need will be cheaper. Choosing SQL Sever and Visual Studio is an excellent way to start fast.Of course, there are trade-offs. The key problem I have with Visual Studio and SQL Server is that you’ll be tied to Microso ft operating systems and Intel hardware. If the day comes when you need to support hundreds of thousands of users, you really don’t have anywhere to go other than buying hundreds of servers, which is a management nightmare.If you go with the Microsoft approach, it sounds like you may not need more than Visual Interdev. If you already know that you’re going to be developing ActiveX components in Visual Basic or Visual C++, that’s warning sign that maybe you should look at the Oracle solution more closely.I want to emphasize that, although these platforms have their relative strengths and weaknesses, if you do it right you can build a world-class application on either one. So if you have an organizational bias toward one of the vendors, by all means go with it. If you’re starting out from scratch, you’re going to have to ask yourself whether your organization leans more toward perfectionism or pragmatism, and realize that both “isms” have their faults.数据库管理数据库（有时拼成Database）也称为电子数据库，是指由计算机特别组织的快速查找和检索的任意的数据或信息集合。

拉曼光谱结合偏最小二乘法定量分析锝洗槽工艺点样品中的锝

拉曼光谱结合偏最小二乘法定量分析锝洗槽工艺点样品中的锝张倩慈;朱海巧;常志远;李定明;白雪;吴继宗【摘要】核燃料后处理工艺流程中,锝洗槽中锝含量是一项重要的技术指标.本工作针对锝洗槽(TcS)工艺点,通过实验获得了拉曼光谱法测定锝浓度的数学模型,结合偏最小二乘法研究了不同建模波长及光谱预处理方法对模型的影响,建立了拉曼光谱法定量测定锝洗槽中锝浓度的分析方法.结果表明,校正标准偏差(RMSEC)为0.005,预测标准偏差(RMSEP)为0.004,r=0.999 3,该方法的检测下限为0.015 g/L,精密度优于5%(n=6).同时考察了铀酰离子浓度改变对锝测定结果的影响,当铀质量浓度为25.00~50.00 g/L,对锝测量结果无显著影响.该方法分析速度快,无需预处理,可应用于锝洗槽工艺点中锝的分析.%The concentration of Tc in technetium scrubbing section (TcS) is an important parameter in the spent fuel reprocessing.This work aims at the TcS point in PUREX process, and with the partial least square (PLS) and Raman spectroscopy the calibration models are established for the determination of pertechnetate.The results show that, the root mean square error of calibration (RMSEC) is 0.005, and the root mean square error of prediction (RMSEP) is 0.004 with the correlation coefficient of 0.999 3.The limit of detection of this method is 0.015 g/L, and the precision is better than 5%(n=6).In addition, the influence of UO2+2 on the determination of Tc was studied in this work.It is found that there is no significant influence on the determination of Tc for the mass concentration of U ranging from 25.00 to 50.00 g/L.This method is very fast and needs no pretreatment.It can be applied to the quantitative determination of Tc in TcS potentially.【期刊名称】《核化学与放射化学》【年(卷),期】2017(039)002【总页数】5页(P174-178)【关键词】锝洗槽;高锝酸根;拉曼光谱;偏最小二乘法;定量分析【作者】张倩慈;朱海巧;常志远;李定明;白雪;吴继宗【作者单位】中国原子能科学研究院放射化学研究所,北京 102413;中国原子能科学研究院放射化学研究所,北京 102413;中国原子能科学研究院放射化学研究所,北京 102413;中国原子能科学研究院放射化学研究所,北京 102413;中国原子能科学研究院放射化学研究所,北京 102413;中国原子能科学研究院放射化学研究所,北京 102413【正文语种】中文【中图分类】O657.37锝是重核裂变生成的主要核素之一[1]，235U热中子裂变产生的锝同位素主要以99Tc为主，其产额为6.13%。

黄铁矿利用过程中铊的迁移特征

２．１矿石、飞灰和炉渣的铊含量
表１列出了三家化工厂各工艺过程产物中的铊含量，云浮硫酸厂全部使用云浮浮选矿石作原料，广
表１各工艺过程产物的铊含量、ｐｉｔ值和Ｆ质量浓度
Ｔａｂｌｅ１Ｔｈａｌｌｉｕｍｃｏｎｔｅｎｔ．ｐＨａｎｄＦ—ｍａｓｓｃｏｎｃｅｎｔｒａｔｉｏｎｏｆｔｈｅｍａｔｅｒｉａｌｓｉｎｔｈｅｔｅｃｈｎｏｌｏｇｙｐｒｏｃｅｓｓ
收稿日期：２００４—１２—３１；改回日期：２００５—０６—１３；接受日期：２００５—０７—０１基金项目：国家自然科学基金（２０４７７００７）；广东省自然科学重点基金（３６２１０）；广东省科技计划项目（２００２Ｃ３１６０７）；广东省重大科技专
项基金（２００４Ａ３０３８ｏ０２）；广州市教育局科学研究基金（２００１．０１）；广州大学科学研究专项基金（ｚｘ．０２０５）作者简介：吴颖娟（１９６２一），女，高级实验师，环境化学专业。Ｅ－ｍａｉｌ：ｆｗｆｙｄ＠１６３．ｔｏｍ
１．２逐级提取实验
黄铁矿脱硫制酸后，铊主要残留在飞灰和炉渣里，为了研究飞灰和炉渣中铊迁移转化的能力，对飞灰、炉渣和沉灰渣中的铊进行逐级提取实验，以了解铊的赋存状态。
１研究和分析方法
１．３浸泡试验
１．１现场调查
中性，可有效防止废渣中的铊淋滤进入环境。
关键词：黄铁矿；铊；飞灰；炉底渣；沉灰渣；迁移，
中图分类号：Ｐ５９５；Ｘ１３１

Anthocyanins Exist in the Circulation Primarily as Metabolites in Adult

Human Nutrition and MetabolismAnthocyanins Exist in the Circulation Primarily as Metabolites in Adult Men 1Colin D.Kay,*†2Giuseppe (Joe)Mazza,†and Bruce J.Holub**Department of Human Biology and Nutritional Sciences,University of Guelph,ON,Canada and †Agriculture and Agri-Food Canada,Paciﬁc Agri-Food Research Centre,Summerland,BC,CanadaABSTRACT Anthocyanins are reported to have many “health promoting”properties;however,despite numerous reports of their bioactivities,their absorption and metabolism in humans are poorly understood.The objective of this research was to detail the pharmacokinetic parameters of anthocyanins after the administration of a 721-mg oral dose of cyanidin 3-glycosides from chokeberry extract to human subjects.Solid-phase extraction,prepara-tive-HPLC,preparative-TLC,HPLC-diode array detection,HPLC-MS,and NMR were utilized to isolate,identity,and quantify anthocyanins in 0-to 7-h (0,1,2,3,4,5,6,7h)serum and 0-to 24-h urine samples (total individual urine voids over 24h).The cumulative concentration of total anthocyanins (parent and metabolites)detected in the serum (0–7h)was 376.65Ϯ16.20(nmol ⅐h)/L (area under the concentration time curve),reaching a maximum concentration (C max ϭ96.08Ϯ6.04nmol/L)within 2.8h.The parent anthocyanins represented only 32.0%[120.63Ϯ2.85(nmol ⅐h)/L]of the total anthocyanins detected with 68.0%[256.02Ϯ5.23(nmol ⅐h)identiﬁed as conjugated metabolites.Additionally,the total urinary excretion of anthocyanins over 24h was 1071.54Ϯ375.46␮g,reaching a maximal rate of excretion (R max ϭ202.74Ϯ85.06␮g/h)at 3.72Ϯ0.83h.Parallel to the serum data,only 32.5%(347.85Ϯ60.61␮g)of the anthocyanins excreted in the urine (total 24h)were the parent compounds with 67.5%(723.69Ϯ92.59␮g)occurring as conjugated metabolites.The metabolites were identiﬁed as glucuronidated and methylated derivatives of the parent cyanidin 3-glycosides.The above results indicate that cyanidin 3-glycosides are rapidly absorbed and metabolized extensively following a moderate-to-high oral dose in humans.J.Nutr.135:2582–2588,2005.KEY WORDS:●anthocyanins●cyanidin 3-glycosides●pharmacokinetics●metabolitesWithin the last decade,many studies have focused on the potential biological activities or health effects of anthocyanins in humans (1–3).Although there is a great deal of evidence indicating the bioactivity of anthocyanins,very little progress has been made in establishing the pharmacokinetics of these compounds,with aspects such as absorption and metabolism left essentially unstudied.Previously,it was reported that an-thocyanins were poorly absorbed and circulated in the blood exclusively as unmetabolized parent glycosides (4–6).It is only recently that researchers have begun to suggest that anthocyanins are metabolized;however,the identiﬁcation of derived metabolites has been limited as a result of their diver-sity and low concentrations in the blood.In our previous investigation focusing on identifying an-thocyanin metabolites in human serum and urine (7),subjects were fed ϳ1.2g of cyanidin 3-glycosides from chokeberries,which resulted in the identiﬁcation of glucuronide and methyl derivatives.The aim of the present investigation was to de-termine the pharmacokinetics of the cyanidin 3-glycosides in humans as well as to establish the extent of their metabolic fate after a lower,more realistic anthocyanin dose (721mg).Speciﬁcally,the chokeberry extract was chosen because itcontained exclusively cyanidin 3-glycosides,thereby permit-ting the monitoring of its metabolites and their pharmacoki-netics.Subsequent investigations will be required to identify the biological activity of these metabolites.SUBJECTS AND METHODSSubjects.Healthy male volunteers (n ϭ3;40Ϯ14.2y old)participated in the cyanidin 3-glycoside consumption intervention.Subjects had a mean BMI of 28.3Ϯ1.6kg/m 2and had no clinical disease as determined using a medical history questionnaire.Subjects were instructed to consume an essentially anthocyanin-free diet (no fruit or vegetables,including foods colored with red or blue dyes)for 2d before the study;they were also asked to avoid taking aspirin or anti-inﬂammatory medications,and antioxidant or herbal supple-ments for 2wk before the investigation.The major constituents of the anthocyanin-free washout diet were milk,tuna,white bread,chicken,and white pliance with the anthocyanin-free diet was monitored using food diaries and conﬁrmed in baseline samples via reverse-phase HPLC (RP-HPLC)3with diode array detection1Supported by the Heart &Stroke Foundation of Ontario (HSFO)and a Natural Sciences and Engineering Research Council of Canada (NSERC)post-doctoral fellowship (C.D.K.).2To whom correspondence should be addressed.E-mail:cdk14@.3Abbreviations used:C-3-ara,cyanidin 3-arabinoside;C-3-gal,cyanidin 3-galactoside;C-3-glu,cyanidin 3-glucoside;C-3-xyl,cyanidin 3-xyloside;CD 3OD,Methanol-d4;CF 3COOD,triﬂuoroacetic acid-d;C max ,maximum concen-tration;DAD,diode array detector;E 440/E max ,ratio of the absorbance intensity at 440nm vs.the maximum absorbance intensity;ESI-MS,electrospray ionization MS;m /z,mass to charge ratio;P,peak;PCA,perchloric acid;P-3-gal,peonidin 3-galactoside;Prep-HPLC,preparative HPLC;Rf,reference value;R max ,maxi-mum rate of urinary excretion;RP-HPLC,reverse phase HPLC;Rt,retention time;0022-3166/05$8.00©2005American Society for Nutrition.Manuscript received 31March 2005.Initial review completed 2May 2005.Revision accepted 27August 2005.2582by guest on December 14, 2010 Downloaded from(DAD).The diets met recommended dietary allowances for macro-nutrients,and no energy restrictions were imposed.All subjects gave written informed consent before the commencement of the investi-gation and experimental procedures followed were in accordance with the Helsinki Declaration of 1975as revised in 1983.Study design.Subjects were admitted to the clinic (Okanagan Clinical Laboratory;Penticton,BC)on the morning of the study dates after fasting (12h,24h no alcohol).Baseline urine samples (ﬁrst void,t ϭ0)were taken in the morning of each study date along with individual urine voids (total volume)over the next 24h (t ϭ0,2,4,6,8,10,12,and 24h).Immediately after baseline (t ϭ0)blood sampling,the volunteers consumed 7.1g of encapsulated (gel caps)chokeberry extract with 250mL of water.The extract contained 4cyanidin 3-glycosides (721.4mg):491.0mg cyanidin 3-galactoside (C-3-gal),175.3mg cyanidin 3-arabinoside (C-3-ara),27.8mg cya-nidin 3-xyloside (C-3-xyl),and 27.3mg cyanidin 3-glucuoside (C-3-glu),as determined by HPLC-DAD (Table 1;Fig.1).Subsequent blood samples were taken at t ϭ1,2,and 3h postconsumption of the extract.The experiment was repeated at a later date (30d wash-out)following the protocol outlined above with one variation.On d 2,blood samples were taken at t ϭ0,3,4,5h and on d 3,at t ϭ0,5,6,7h (n ϭ3;levels ϭ0,1,2,3,4,5,6,7).The sampling regimen was necessary to acquire the volume of blood needed for the analysis.Individual urine samples were also collected over 24h (levels ϭ0,2,4,6,8,10,12,24)at each visit (n ϭ3ϫ3repetitions;y ϭ9replicates).After consumption of the extract,subjects were instructed to consume 250mL of water every hour for 5h with subsequent ad libitum consumption.An anthocyanin-free lunch and dinner was provided for the subjects at 4and 8h postconsumption of the extract.Blood samples (ϳ20mL)were drawn by venipuncture from a brachial vein into 10-mL evacuated glass tubes (2tubes/time point)(Vacutainer;Becton Dickinson).The blood samples were allowed to clot at room temperature for 30min.Samples were then immediately centrifuged (1000ϫg)for 15min at 5°C to recover the serum.Urine samples were acidiﬁed with 20␮L of 12mol/L HCl/mL urine uponSPE,solid phase extraction;t ϭ0,baseline;t 1/2,elimination half-life;t 1/2a ,absorption half-life;t max ,time point at which maximal serum concentration oc-curs;t maxR ,time point at which maximal rate of urinary excretion occurs;TFA,triﬂuoroacetic acid;UV-vis,UV-visible.TABLE 1Identiﬁcation of anthocyanins and anthocyanin metabolites in human urine and serum after the consumptionof 721mg of cyanidin 3-glycosides 1–3Peak Anthocyanin/identityRtMWparent/daughterfragmentAbsorption spectraTLC (Rf)␭max E 440/E max (as %)1Cyanidin 3-galactoside 23.8449/287280,517310.362Cyanidin glucuronide 27.6463/287280,517310.383Cyanidin 3-arabinoside 29.6419/287280,517310.454Peonidin 3-galactoside33.4463/301280,517310.425Methylated cyanidin glucuronide 36.3477/301280,514370.396Methylated cyanidin glucuronide 37.0477/301280,515320.44Characteristics of anthocyanin standardsCyanidin 3-galactoside 4,523.8449/287280,517310.36Cyanidin 3-arabionside 429.6419/287280,517310.45Cyanidin 3-xyloside 439.0419/287280,517290.48Cyanidin 3-glucoside 4,527.3449/287280,517370.40Cyanidin 543.6287280,526230.80Peonidin 550.8301280,528260.841Identiﬁcation (retention time and absorption spectra)based on Agilent HPLC-DAD.2Identiﬁcation (MW)based on Waters microcapillary HPLC-MS.3Comparisons made between serum and urinary samples using HPLC-DAD (Fig.1,C and D )indicated that the serum peaks matched both retention time and UV-vis spectrum with the peaks identiﬁed as anthocyanins in the urine,and were therefore regarded as the same compounds.4Data based on analysis of puriﬁed anthocyanin from chokeberry extract.5Data based on analysis of purchased standard(Extrasynthese).FIGURE 1Chromatograms of anthocyanins in baseline human urine sample (A ),chokeberry extract (B ),typical serum sample (C ),and typical urine sample (D ).HPLC analysis as outlined in the methods.The identiﬁcation of each peak represented above (peaks 1–6)is given in Table 1.Urine and serum pharmacokinetic data of each compound represented by peaks 1–6are given in Tables 2and 3,respectively.PHARMACOKINETICS OF CYANIDIN 3-GLYCOSIDES 2583by guest on December 14, 2010Downloaded fromcollection.The serum and urine were stored at Ϫ80°C after removal/collection.Materials/reagents.The chokeberry extract (no.74190,lot L18010)was purchased from Artemis International.The anthocya-nin standards,cyanidin 3-glucoside chloride,cyanidin 3-galactoside chloride (ideain chloride),peonidin 3-glucoside chloride,cyanidin chloride,and peonidin chloride were purchased from Extrasynthese.Formic acid (Fisher Scientiﬁc),hydrochloric acid (HCl),triﬂuoro-acetic acid (TFA),and glacial acetic acid (DH)were all reagent grade;all solvents used for HPLC analysis were HPLC grade.Anthocyanin analysis.The chokeberry extract,serum,and urine anthocyanins were quantiﬁed via HPLC-DAD.Individual serum sam-ples were collected every hour for 7h (n ϭ3)and individual urine voids were collected (separately)over a 24-h period (n ϭ3ϫ3repetitions)as detailed in the study design.Every serum and urine sample was analyzed and quantiﬁed individually via HPLC-DAD before pooling for identiﬁcation purposes.After quantiﬁcation,urine samples were pooled for puriﬁcation (XAD adsorption chromatogra-phy),isolation [preparative (prep)-HPLC and prep-TLC],and iden-tiﬁcation (HPLC-MS;HPLC-DAD;TLC;NMR).Identiﬁcation of the anthocyanins was based on the matching of molecular weight (parent and daughter fragments),retention time (Rt),␭maxvis ,E 440/E max ,and reference (Rf)values with those of available anthocyanin standards as well as isolated chokeberry anthocyanins (Table 1).TLC data (post-acid hydrolysis)were utilized for additional conﬁrmation when considered necessary.Peaks lacking absorption maxima in the 280and 520nm range were not considered anthocyanin metabolites,and no attempt was made to identify these unknown compounds.Selected pharmacokinetic variables were determined for the identi-ﬁed compounds from the initial HPLC quantitative results (Table 2and 3;Figs.2and 3).Methods of extraction [C 18solid-phase extraction (SPE)]were modiﬁed from Kay et al.(7)and Tsuda et al.(8).The anthocyanins were extracted from biological ﬂuids before HPLC analysis using disposable SPE C 18cartridges (Supelclean ENVI-186mL 2000mg;Sigma;lot #SP2419C).Unﬁltered blood serum (4mL)or 2–10mL of unﬁltered acidiﬁed urine (2mL,t ϭ0–9h;or 10mL,t ϭ10–24h)were utilized for the extraction.Individual blood and urine samples (nonpooled)were extracted in duplicate,and each extract was in-jected into the HPLC column in duplicate (total of 4injections/sample)for quantitative HPLC analysis.Puriﬁcation of anthocyanins in pooled human urine samples (postquantitative HPLC analysis)was performed using Amberlite XAD-7polymeric adsorbent (Sigma;Lot #77H0157)before isolation of individual anthocyanin/metabolite peaks using prep-HPLC.The procedure was based on general methods as described by Markham (9).The column (50ϫ3.0cm)was ﬁlled with presoaked (24h EtOH:H 2O v:v)XAD-7resin (volume of 212cm 3)and loaded with 1L of unﬁltered acidiﬁed urine (pH Ϸ2.5).The column was drained under gravity,then washed with 500mL acidiﬁed H 2O (0.1%TFA),followed by 500mL MeOH:H 2O (30:70;0.1%TFA;ﬂow rate 10mL/min).Finally,the anthocyanin extract was eluted with 500mL of MeOH:H 2O (75:25;0.1%TFA;ﬂow rate 10mL/min)and evapo-rated.The anthocyanin-rich urine extract was then further puriﬁed via prep-HPLC.Analytical HPLC analysis was performed on an Agilent 1100series HPLC (Agilent Technologies)using a Zorbax SB C 18RP column (5␮m,4.6ϫ250mm)with a Supelguard LC-18guardTABLE 3Pharmacokinetic parameters of cyanidin 3-glycosides and corresponding metabolites in human serumafter the consumption of 721mg of cyanidin 3-glycosides 1PeakAnthocyanin/identityC max T max 2AUC t 1/2a 3nmol/Lh (nmol ⅐h)/L h 1Cyanidin 3-galactoside 23.36Ϯ 2.33 2.5(2–3)66.64Ϯ 3.27Ͻ1.352Cyanidin glucuronide 14.51Ϯ 4.04 2.0(2)90.93Ϯ 4.083Cyanidin 3-arabinoside 8.85Ϯ0.50 3.5(3–4)53.99Ϯ 2.43Ͻ1.674Peonidin 3-galactoside3.76Ϯ0.784.0(4)30.67Ϯ 1.125Methylated cyanidin glucuronide 12.81Ϯ0.42 2.5(2–3)34.42Ϯ 2.776Methylated cyanidin glucuronide 32.79Ϯ10.882.5(2–3)100.00Ϯ12.851Pharmacokinetic data are means ϮSD,n ϭ3,over 7h as quantiﬁed via HPLC-DAD (Table 1).2Values are medians (range).3t 1/2a :precise absorption half-lives for 2of the 3subjects could not be determined because there was only one serum sample (t ϭ1h)during the absorption phase.Therefore,as a result of the rapid absorption phase (Ͻ1h)for 2of the 3subjects,SDs cannot be speciﬁed.The absorption half-life values above are from 1subject only and it can be assumed that the mean absorption half-life for the 3subjects would be Ͻ1h.For a more accurate estimate of absorption additional half-life samples are required before the end of h 1.The t 1/2a value was determined using the method of residuals (14).TABLE 2Pharmacokinetic parameters of cyanidin 3-glycosides and corresponding metabolites in human urineafter the consumption of 721mg of cyanidin 3-glycosides 1PeakAnthocyanin/identityQuantityR maxt maxR t 1/2␮g␮g/h h h 1Cyanidin 3-galactoside 267.55Ϯ90.8248.74Ϯ14.80 3.39Ϯ1.14 3.72Ϯ0.422Cyanidin glucuronide 173.25Ϯ86.4639.47Ϯ20.77 3.17Ϯ0.86 3.63Ϯ0.563Cyanidin 3-arabinoside 80.30Ϯ31.3013.17Ϯ 4.68 2.94Ϯ1.39 4.05Ϯ0.824Peonidin 3-galactoside103.88Ϯ35.6319.27Ϯ7.74 3.39Ϯ1.14 4.28Ϯ0.595Methylated cyanidin glucuronide 111.06Ϯ60.6119.61Ϯ10.51 4.05Ϯ1.21 4.53Ϯ0.926Methylated cyanidin glucuronide 335.50Ϯ187.6666.63Ϯ37.134.05Ϯ1.214.39Ϯ0.831Pharmacokinetic data are means ϮSD,n ϭ9,over 24h as quantiﬁed via HPLC-DAD (Table 1).KAY ET AL.2584 by guest on December 14, 2010Downloaded fromcolumn (C 185␮m,4.6ϫ20mm;Supelco,Sigma-Aldrich).The following procedure was modiﬁed from previously published methods (7,10).Prep-HPLC separation of individual anthocyanins from pooled urine samples was performed on a Waters Chromatographic system (Waters)comprised of 3Model 510pumps,and a Model 490pro-grammable multiwavelength detector set at 525nm.The preparative column system (Waters PrepPak)consisted of 2Nova-Pak HR C 18radial compression cartridges (25ϫ100mm;6␮m,60Å;PrepPak Cartridge;Waters)with a Nova-Pak HR C 18guard insert (Waters).Injections were carried out on a manual injection port (Rheodyne)equipped with a 500-␮L injection loop.The column and injector were kept at ambient temperature,with an injection volume of 250–500␮L.The mobile phase consisted of 0.1%TFA in water (solvent A)and 100%MeOH (solvent B).The ﬂow rate was 15mL/min with an isocratic run of 80%A and 20%B.Peaks on the chromatogram corresponding to anthocyanins,as identiﬁed by spec-tral analysis (peaks detected at 525nm with ␭max 250–300and 500–550nm),were collected manually from the prep-HPLC column and concentrated using a rotary evaporator.The remaining H 2O was removed in a freeze-dryer and samples were sealed under nitrogen gas and stored at Ϫ80°C until further analysis.TLC procedures were based on methods described by Wagner and Bladt (11).Normal phase prep-TLC was utilized for the ﬁnal puriﬁ-cation of individual anthocyanins separated from the pooled urine samples (20ϫ20250-␮m silica gel Redi/plates;Analtech).The solvent system consisted of ethyl acetate,glacial acetic acid,formic acid,and H 2O (100:11:11:26).After the plates were developed,the anthocyanin bands were removed and dissolved in 5mL of MeOH containing 0.1%formic acid.The ﬁnal solution was ﬁltered through a 0.45Ϫ␮m polyvinylidene ﬂuoride syringe ﬁlter,evaporated in arotary evaporator,and brought to dryness in a freeze-dryer.The remaining extract was sealed under nitrogen gas and stored at Ϫ80°C until further analysis.For the postacid hydrolysis of anthocyanins for veriﬁcation of aglycones,0.20-mm silica gel 60analytical TLC plates (Macherey-Nagel;Batch 901/021)containing a ﬂuorescent indicator (UV 254)were used.Acid hydrolysis of the anthocyanin glycosides was achieved by dissolving a portion of the dry anthocyanin extracts in 200␮L of 2mol/L HCl.The solution was then sealed under nitrogen gas and heated to 100°C for 1.5h.The samples were then cooled immediately in an ice bath and plated using the above solvent system.MS identiﬁcation of individual compounds was conducted postseparation via prep-HPLC and prep-TLC (as outlined above).The analysis was carried out on a Waters Alliance 2695HPLC coupled serially with a Waters 2996photodiode array detector and a Waters ZQ 2000quadrupole analyzer utilizing the electrospray ionization interface (ESI-MS)(Waters).The chromatographic separation was performed on a 250ϫ 2.0mm Synergi 4-␮m Max-RP 80Åcolumn (Phenomenex)with a 4ϫ2mm Phenome-nex Max RP guard cartridge (Phenomenex).Injection volumes were 2␮L.The mobile phase consisted of an acidiﬁed (0.18%v:v acetic acid)water:acetonitrile mixture (95:5)(solvent A)and 100%acetonitrile (solvent B).The ﬂow rate was 130␮L/min;the solvent gradient program used 100%A at 0–2min and was ramped to 100%B at 60min.The instrument was operated in electrospray positive ion mode (ES ϩ).Micromass ZQ single quadrupole MS with electrospray interface and MassLynx 4.0software (Micro-mass)was used for data acquisition.The MS parameters were loosely based on methods previously published by Felgines et al.(12)and Garcı´a-Beneytez et al.(13).NMR spectra were obtained on a Bruker Avance DRX 500MHz spectrometer (Bruker Biospin),equipped with a cryoprobe,at 300K.For 1H (500MHz)NMR,a solvent mixture of methanol-d4to triﬂuoroacetic acid-d (CD 3OD:CF 3COOD)(98:2,v:v,200␮L)was used and ␦values were referenced to CD 3OD (CHD 2OD at 3.30ppm).Analysis of the 1H NMR spectra was based on the comparison of the chemical shift and relative intensity of the signals with those of standard compounds.Statistical analysis.The primary analyses were performed on urinary values (urinary values only)using the mixed models proce-dure (PROC MIXED)in SAS (version 9.1;SAS Institute).The data are presented as means ϮSD unless otherwise stated.The distribu-tions of anthocyanins were corrected with natural logtransforma-FIGURE 2Time course of total,parent,and metabolized antho-cyanins in human urine (A )and serum (B )of subjects after the con-sumption of 721mg of cyanidin 3-glycosides.For urinary (A ;n ϭ9replicates)and serum (B ;n ϭ3)data,values are means ϮSD as represented by vertical bars.(A )Different letters for the points indicate that the concentrations of total urinary anthocyanins differed across time,P Ͻ0.05.Identiﬁcation of each peak as labeled in the legend (as peaks 1–6)is given in Table 1.Urinary and serum pharmacokinetic data of each compound represented by peaks 1–6,is given in Tables 2and 3,respectively.FIGURE 3Cumulative time course of individual anthocyanins excreted in human urine after the consumption of 721mg of cyanidin 3-glycosides.Values are means ϮSD (n ϭ9replicates)as represented by vertical bars.Different letters for the lines indicate that the concen-trations differed at the level of the individual anthocyanin,P Ͻ0.05.For peak identities,refer to Table 1.For urinary and serum pharmacokinetic data of each compound represented by peaks 1–6,refer to Tables 2and 3,respectively.PHARMACOKINETICS OF CYANIDIN 3-GLYCOSIDES 2585by guest on December 14, 2010Downloaded fromtions,and unadjusted values are reported.The total level of antho-cyanins as well as the levels of individual anthocyanin species were evaluated over time.The model included time (levels ϭ0,2,4,6,8,10,12,and 24h)and anthocyanin species (levels ϭ1,2,3,4,5,6)as ﬁxed effects,and subjects (n ϭ3)and their replicate treatments (3replicates)were treated as random variables (y ϭ9replicates).For all analyses,the signiﬁcant main effects (P Յ0.05)were investigated using the Tukey-Kramer test.In addition,noncompartmental pharmacokinetic evaluation of urine and serum parent compounds,and their metabolites was per-formed on untransformed data according to standard methods (14).For urinary variables,there was no effect of subject (P ϭ0.3);therefore,subject (n ϭ3)and their replicate treatments (3replicates)were collapsed (y ϭ9replicates)for the determination of means (ϮSD)in the pharmacokinetic analysis.The analyses of serum variables included 3subjects with no replications and are presented as means ϮSD (n ϭ3;no replicates).Calculation of the area under the plasma concentration time curve was based on the mean serum concentra-tions of individual subjects using the trapezoidal rule.Absorption half-lives were determined graphically (SPSS SigmaPlot,IL)using the method of residuals.The geometric means of the elimination half-lives were determined graphically from the renal excretion rates of individual subjects.RESULTSSerum and urine samples collected before the administra-tion of the chokeberry extract (baseline,t ϭ0)contained no detectable anthocyanins (Fig.1A ).Postconsumption,both cyanidin 3-galactoside and cyanidin 3-arabinoside [peak (P)1,3;Fig.1]were present in the serum and urine.Both glucuronidated (loss m /z ϭ176upon fragmentation)and methylated (m ϩ14)derivatives of cyanidin were also present.In total,4derivatives/metabolites were isolated from the urine in sufﬁcient quantities for structural identiﬁcation.One metabolite (P2;Fig.1C and D )was identiﬁed as a cyanidin glucuronide,as indicated by its molecular ion at m /z 463and fragment at m /z 287,indicating a loss of m /z 176upon fragmentation (representing a glucuronide residue;m /z ϭ176;Table 1).Additionally,the hydrolysis of this compound re-sulted in an aglycone with the same HPLC Rt,UV-vis spectral data,and TLC Rf value as the purchased cyanidin standard.There was insufﬁcient evidence to determine the exact posi-tion of the glucuronide residue because the NMR spectra were uninterruptible (result of insufﬁcient quantity and poor solu-bility).The second identiﬁed metabolite (P4;Fig.1C and D )had the chemical characteristics of a methylated derivative of C-3-gal,having a parent ion of m /z 463,daughter fragment of m /z 301(consistent with methylation;m /z 287ϩ14ϭ301),and loss of m /z 162upon fragmentation (indicative of a hexose sugar;m /z ϭ162;Table 1).The hydrolysis of the compound resulted in an aglycone with similar HPLC Rt,UV-vis spectral data,and TLC Rf value as the purchased peonidin standard.There was insufﬁcient evidence to determine the exact posi-tion of the methylation and glucuronidation because the NMR spectra were uninterruptible (result of insufﬁcient quantity and poor solubility).Two other metabolites (P5,6;Fig.1,C and D)were identiﬁed as methylated derivatives of cyanidin glucuro-nide,having parent ions of m /z 477and daughter fragments of m /z 301,indicating a loss of m /z 176upon fragmentation (consistent with glucuronic acid residue;m /z ϭ176;Table 1).The derivatives were dissimilar to peonidin,having different HPLC and TLC parisons made between serum and urinary samples using HPLC-DAD (Fig.1,C and D;Table 1)indicated that the serum peaks matched both reten-tion time and UV-vis spectrum of the peaks identiﬁed as anthocyanins in the urine,and were therefore regarded as the same compounds.As a result of the sampling regimen,the mixed models procedure was performed on urinary variables only.There was a signiﬁcant main effect of time (P Ͻ0.0001)for the total (P1–6)and individual level of anthocyanins (P1,2,3,4,5,6),as well as a signiﬁcant interaction between time and anthocyanin species (P ϭ0.0016).Additionally,the level of total antho-cyanins did not differ among the 3subjects (P ϭ0.30).Serum variables were utilized only for pharmacokinetic analyses.The pharmacokinetic analysis of urine and serum variables (Tables 2and 3)and their graphical representations (Figures 2and 3)utilized untransformed data as was previously described (14).The results of both urinary (Table 2)and serum (Table 3)analyses indicated that parent compounds and their metabo-lites had similar pharmacokinetic proﬁles (T max and T 1/2).DISCUSSIONIn previous investigations,it was questioned whether the concentration of anthocyanins observed in the blood was sufﬁcient to yield biological activity.We hypothesized that unidentiﬁed anthocyanin metabolites may contribute to the reported effects of anthocyanins.A previous investigation by our group identiﬁed anthocyanin metabolites in human serum and urine after the consumption of cyanidin 3-glycosides in chokeberries (7).Subjects were fed ϳ1.2g of cyanidin 3-gly-cosides,leading to the identiﬁcation of glucuronide and meth-ylated derivatives in the serum and urine.The aim of the present investigation was to identify metabolites and their time course (pharmacokinetics)after a lower,more realistic anthocyanin dose.The present investigation involved a 721-mg oral dose of cyanidin 3-glycosides with the subsequent collection of serum over 7h and urine over 24h.This dose is equivalent to ϳ120–230g of whole berries (fresh weight)(15).Additionally,a 721-mg dose is roughly the median dose of 12reviewed anthocyanin human consumption trials in the literature (788Ϯ883mg)(5,10,12,16–24).The chokeberry extract as utilized in the present investigation was chosen for its simplistic anthocyanin proﬁle,consisting of only cyanidin 3-glycosides.The use of a fruit extract containing only one anthocyanidin species (cyanidin)was crucial for establishing the origin of methylated cyanidin derivatives.Further inves-tigations are required to identify the biological activity of these metabolites.In the present investigation,no anthocyanins were identi-ﬁed in the serum or urine of fasting subjects suggesting that the washout phase and prestudy dietary exclusion of anthocyanins was sufﬁcient.Glucuronidation was the major metabolic path-way observed for anthocyanin metabolism in the present in-vestigation,representing 59.8and 57.8%of the total antho-cyanins detected in the blood and urine,respectively.Methylation was the second most commonly observed meta-bolic transformation for anthocyanins,representing 43.8and 51.4%of the total anthocyanins detected in the serum and urine,respectively.Even though only a few researchers have reported glucuronidated and methylated anthocyanins in the urine and blood of humans and animals (7,8,12),methylated and glucuronidated derivatives of the ﬂavonoid quercetin are well documented (18,25,26).Although some recent investi-gations described the detection of anthocyanin metabolites in urine,this is the ﬁrst study to give detailed pharmacokinetic parameters for anthocyanin metabolites.In the present investigation,no attempt was made to iden-tify HPLC peaks lacking characteristic anthocyanin proﬁles (maxima in the 280and 520nm range).There are likely other anthocyanin metabolites (breakdown products)present in the serum and urine with absorbance outside the 240-to 525-nmKAY ET AL.2586 by guest on December 14, 2010Downloaded from。

污泥中重金属的形态提取―BCR三态提取法

复杂体系分离分析结课报告污泥中重金属的形态提取—BCR三态提取法污泥中重金属的形态提取——BCR三态提取法摘要污泥中重金属的形态分析成为评估重金属可迁移性及生物可利用性的有效方式。

围绕其形态提取，西方研究者提出了多种提取方法。

BCR三态提取法逐渐被各国研究者接受，并在实际应用中的到推广。

这也为不同地域污泥重金属毒性评估提供了一个统一的标准。

关键词污泥重金属形态提取BCR三态提取法评估引言自1857年英国伦敦建立世界第一个污水处理厂以来，世界上污水处理业快速发展而不断产生新的废弃物一污泥，同时污泥的处理也成为政府管理中的一项重要问题。

目前，国内外应用比较广泛的污泥处理方式主要有4种，分别为填埋处理，填海处理，焚烧处理和土地利用。

各国在四种处理方式所占处理总量的比例不同。

污泥填埋处理是意大利、荷兰和德国对污泥的主要处理方式。

污泥填海处理的方法简单，不用花费大量能源，却可污染海洋，会导致全球环境问题，此方法目前已受到限制。

污泥的焚烧处理可以最大量地减少污泥体积，但设备和运行费用昂贵，易造成大气污染问题。

而污泥的土地利用能够实现其稳定化、无害化、资源化的目的，因此土地利用逐渐为人们所重视。

但是要实现污泥的土地利用，首先要检测、评估其重金属毒性。

1污泥重金属形态提取现状传统的对重金属的污染分析一般只是测定样品中待测元素的总量或总浓度。

然而，从20世纪70年代开始，人们认识到重金属的生物毒性和生物有效性不仅与其总量有关，而且更大程度上取决于该元素在环境中存在的化学形态及物理形态[1,2]。

因此，人们对环境介质中的重金属研究的侧重点也逐渐集中到确定重金属的形态分布及其影响方面。

颗粒物中重金属的形态分析是从土壤科学研究发展起来的，其方法是借用土壤中选择性提取金属的化学试剂逐级提取以确定污泥颗粒物中金属的形态[3]。

目前，国内外采用的重金属的形态连续提取技术多种多样，且由于采用的提取试剂以及操作方法的不同，从而也产生了由于缺乏统一标准而使实验数据难以比较状况和结论相差较大等问题。

正交试验优化淫羊藿总黄酮和多糖的分步提取工艺优化

正交试验优化淫羊藿总黄酮和多糖的分步提取工艺优化付亮1，袁璟亚2，杨瑞武1，张利1，周永红2，丁春邦1,*(1.四川农业大学生命科学与理学院，四川雅安 625014；2.四川农业大学作物基因资源与遗传改良教育部重点实验室，四川温江 611130)摘要：通过对淫羊藿总黄酮和多糖进行分步提取工艺优化，探寻一种提高淫羊藿综合利用率的提取工艺。

利用单因素结合正交试验优化淫羊藿总黄酮的超声波辅助提取工艺，并对此工艺所得药渣进行多糖的水煮提取工艺优化。

结果表明，总黄酮提取的最优工艺条件为按料液比1:10(g/mL)加入70%乙醇溶液，在60℃提取温度、150W 超声功率下提取2次，每次5min ，提取效率达4.72%；多糖提取的最优工艺条件为按料液比1:10加入水，在90℃提取温度提取2次，每次30min ，提取效率达1.89%。

优化后的淫羊藿总黄酮和多糖分步提取工艺操作简单、能耗低、提取效率高、多糖损失率低、较大限度地提高了淫羊藿的综合利用率。

关键词：淫羊藿；总黄酮；多糖；分步提取Orthogonal Array Design for the Optimization of Successive Extraction of Total Flavonoids and Polysaccharidesfrom Epimedium brevicornum MaximFU Liang 1，YUAN Jingya 2，YANG Rui-wu 1，ZHANG Li 1，ZHOU Yong-hong 2，DING Chun-bang 1,*(1. College of Life Science, Sichuan Agricultural University, Ya ’an 625014, China ；2. Key Laboratory of Crop Germplasm Resources and Gene Improvement, Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China)Abstract ：Objective: To optimize process conditions for the extraction of total flavonoids from the whole plant of Epimedium brevicornum Maxim and for further extraction of polysaccharides from the remaining residue. Methods: A two-step sequential extraction procedure was proposed for the extraction of total ﬂ avonoids by ultrasonic-assisted extraction and polysaccharides by hot water extraction. Results: The optimum conditions for the extraction of total ﬂ avonoids were found to be two extraction cycles at 60 ℃ and a microwave power of 150 W for 5 min each cycle with 70% ethanol at a solid-to-solvent ratio of 1:10 (g/mL), resulting in an extraction ef ﬁ ciency of 4.72%. The optimum conditions for the extraction of polysaccharides were found to be two extraction cycles at 90 ℃ for 30 min each cycle with a residue-to-water ratio of 1:10 g/mL, resulting in an extraction ef ﬁ ciency of 1.89%. The optimized procedure for sequential extraction of total ﬂ avonoids and polysaccharides was characterized by easy operation, low energy consumption, high extraction efficiency, low polysaccharide loss and enhanced comprehensive utilization of Epimedium brevicornum Maxim.Key words ：Epimedium brevicornum Maxim ；total ﬂ avonoids ；polysaccharides ；two-step extraction 中图分类号：R284.2 文献标识码：A文章编号：1002-6630(2012)24-0056-05收稿日期：2011-10-14基金项目：教育部“长江学者和创新团队发展计划”项目(IRT0453)；四川省科技厅应用基础项目(2008JY0094-2)作者简介：付亮(1984—)，男，硕士研究生，主要从事药用植物资源研究。

异构催化剂生产生物柴油1111

Heterogeneous Catalysts for Biodiesel ProductionMartino Di Serio,†Riccardo Tesser,†Lu Pengmei,‡and Elio Santacesaria*,†Dipartimento di Chimica,Uni V ersitàdi Napoli “Federico II”,V ia Cintia 80126Napoli,Italy,andGuangzhou Institute of Energy Con V ersion,Academy of Science,ChinaRecei V ed May 17,2007.Re V ised Manuscript Recei V ed September 7,2007The production of biodiesel is greatly increasing due to its enviromental beneﬁts.However,production costs are still rather high,compared to petroleum-based diesel fuel.The introduction of a solid heterogeneous catalyst in biodiesel production could reduce its price,becoming competitive with diesel also from a ﬁnancial point of view.Therefore,great research efforts have been underway recently to ﬁnd the right catalysts.This paper will be concerned with reviewing acid and basic heterogeneous catalyst performances for biodiesel production,examining both scientiﬁc and patent literature.IntroductionNowadays,biodiesel (a mixture of fatty acid methyl esthers,FAMEs)has become very attractive as a biofuel because of its environmental beneﬁts s it has less air pollutants per net energy than diesel and is nontoxic and biodegradable s and because it is produced from renewable sources with high energetic efﬁciency:biodiesel yields from an estimated 90%1to 40%2more energy than the energy invested in producing it.Most biodiesel is produced today by the transesteriﬁcation of triglycerides of reﬁned/edible type oils using methanol and an alkaline catalyst (NaOH,NaOMe):3–5The reaction isnormally performed at 60–80°C.The glycerol and FAME are separated by settling after catalyst neutralization.The crude glycerol and biodiesel obtained are then puriﬁed.However,production costs are still rather high,compared to petroleum-based diesel fuel.3There are two main factors that affect the cost of biodiesel:the cost of raw materials and the cost of processing.3Processing costs could be reduced through simpliﬁed opera-tions and eliminating waste streams.6–9A solution to thisproblem could be transesteriﬁcation in supercritical methanol without using any catalyst.6,7As a matter of fact,in this case,the reaction is very fast (less than 5min)and the absence of catalyst decreases downstream puriﬁcation costs.6,7Even if some production plants use this technology in Europe,6the reaction requires very high temperatures (350–400°C)and pressures (100–250bar)and thus high capital costs.6,7The use of heterogeneous catalysts could be an attractive solution.8,9As a matter of fact,heterogeneous catalysts can be separated more easily from reaction products and the reaction conditions could be less drastic than the methanol supercritical process.In 2006a 160000t/y commercial plant started up using a heterogeneous catalyst.8The plant is based on the Hesterﬁp-H technology developed by the Institute Français du Petrole (IFP).8,9The catalyst employed in the Hesterﬁp-H technology is a mixed oxide of zinc and aluminum.9The Hesterﬁp-H technology operates at 200–250°C but does not require catalyst recovery and aqueous biodiesel treatment steps:the puriﬁcation steps of products are therefore much more simpliﬁed and very high yields of methyl esters s close to theoretical values s are obtained.6,9Glycerol is directly produced with high purity levels (at least 98%)and is free from any salt contaminants.9This aspect is very important from the economical point of view because it reduces the cost of obtaining high-grade glycerol,thus increasing the proﬁtability of the process.Moreover,in order to lower the costs and make biodiesel competitive with petroleum-based diesel,less-expensive feed-stocks such as waste fats or nonedible type oils,could be used.3–7,10However homogeneous alkaline catalysts in the transesteriﬁcation of such fats and oils cannot directly be used due to the presence of large amounts of free fatty acids (FFAs);3–5for the use of these catalysts,the FFA concentration should be less than 0.5%(w/w)to avoid the formation of high*Corresponding author.Fax:0039081674026.E-mail:elio.santacesaria@unina.it.†Universitàdi Napoli “Federico II”.‡Academy of Science.(1)Hill,J.;Nelson,E.;Tilman,D.;Polasky,S.;Tiffany,D.Proc.Natl.Acad.Sci.2006,103,11206–11210.(2)Wesseler,J.Energy Policy 2007,35,1414–1416.(3)Ma,F.;Hanna,M.A.Bioresour.Technol.1999,70,1–15.(4)Pinto,A.C.;Guarieiro,L.L.N.;Rezende,M.J.C.;Ribeiro,N.M.;Torres,E.A.;Lopes,W.A.;de P.Pereira,P.A.;de Andrade,J.B.J.Braz.Chem.Soc.2005,16,1313–1330.(5)Lotero,E.;Liu,Y.;Lopez,D.E.;Suwannakaran,K.;Bruce,D.A.;Goodwin,J.G.,Jr.Ind.Eng.Chem.Res.2005,44,5353–5363.(6)Huber,G.W.;Iborra,S.;Corma,A.Chem.Re V .2006,106,4044–4098.(7)Demirbas,A.Prog.Energy Combust.Sci.2007,33,1–18.(8)Dupraz,C.BIO-Energy -Prospect for India-France Partnership -18th April 2007-New Delhi,/events/4001/Mr_Dupraz.pdf (accessed Aug 2007).(9)Bournay,L.;Casanave,D.;Delfort,B.;Hillion,G.;Chodorge,J.A.Catal.Today 2005,106,190–192.(10)Kulkarni,M.G.;Dalai,A.K.Ind.Eng.Chem.Res.2006,45,2901–2913.Energy &Fuels 2008,22,207–21720710.1021/ef700250g CCC:$40.75 2008American Chemical SocietyPublished on Web 12/04/2007soap concentrations as a consequence of the reaction of FFAs with the basic catalyst:R-COOH +NaOH f R-COOHNa +H 2OThe soap causes downstream processing problems in product separation because of emulsion formation.3,6Several methods have been proposed to solve these prob-lems,11but the most useful seem to be the following:5,10,12–15(a)use of enzymes.A Lypase enzyme catalyzes both transesteriﬁcation of triglycerides and esteriﬁcation of FFAR-COOH +MeOH a R-COOMe +H 2Oin one step.9,11–13(b)use of acid catalysts.Acid catalyst can also promote esteriﬁcation and transesteriﬁcation.5,10,15(c)pre-esteriﬁcation method.FFAs are ﬁrst esteriﬁed to FAMEs using an acid catalyst,and then,transesteriﬁcation is performed,as usual,by using an alkaline catalyst.5,10Enzyme-based transesteriﬁcation is carried out at moderate temperatures with high yields,but this method cannot be used in industry today due to high enzyme costs,and the problems related to its deactivation caused by feed impurities.10,12–14The enzyme can be immobilized on a support to obtain a heterogeous catalyst,but again,the use will only be possible if the enzyme costs are reduced s as in the case of enzyme use in detergents,dairy products,textile,and leather processing.12However,the use of enzymes is not explored in this review which will be devoted to the use of heterogeneous acid and basic catalysts.More information on the use of enzymes in biodiesel production can be found in recent papers.10,12–14Methods b and c seem to be more attractive.Concerning method b s use of an acid catalyst for both esteriﬁcation and transesteriﬁcation reactions s Zhang et al.16,17recently showed,by a technological assessment of different continuous processes,that the homogeneous H 2SO 4-catalyzed process using waste oil is technically feasible and less complex than a two-step process (pre-esteriﬁcation with homogeneous acid catalyst and alkali-catalyzed steps).However,this process gives rise to problems linked with the corrosive action of the liquid acid catalyst and to the high quantity of byproduct obtained.5,15Basu and Norris 18and more recently Di Serio et al.15and Siano et al.19showed the possibility to perform triglyceride (TG)transesteriﬁcation and FFA esteriﬁcation in a single step,using low concentrations of Lewis acid homoge-neous catalysts (carboxylic acid of particular metals).However,this process also gives rise to problems linked with the need to remove catalysts from products by downstream puriﬁcation.15A solid acid catalyst could eliminate these problems.5,8The homogeneous acid-catalyzed pre-esteriﬁcation of FFA s method c s is a common practice in reducing FFA levels in high FFA feedstock,before performing the base-catalyzed transesteri-ﬁcation.4,5,10The main drawback of the pre-esteriﬁcation method c consists again in the necessity to remove the homogeneous acid catalyst from the oil after pre-esteriﬁcation.So for improving the process,the solution is again the use of a heterogeneous esteriﬁcation catalyst.5From the above discussion,it is clear that the introduction of a solid catalyst in biodiesel production could reduce its price,so biodiesel could become competitive with diesel also from an economic point of view.Therefore,great research efforts have been underway recently to ﬁnd the right catalysts.Several general reviews on biofuels and biodiesel production have been published:3–7,10one concerns both homogeneous and heterogeneous acid catalysts.5In the second part of a general review on biodiesel production,Lotero et al.20also included an in-depth review on heterogeneous catalysts used in transesteri-ﬁcation reactions.Together with the scientiﬁc and patent literature concerning biodiesel production,in some cases,we have also considered results reported on the transesteriﬁcation or esteriﬁcation of model molecules like triacetin or acetic acid to explain the reaction mechanisms and catalytic behavior of heterogeneous catalysts.However,it must be pointed out that in some cases the data obtained with model molecules cannot be used to predict the behavior of oils/fats and fatty acids because the polar and steric effects of the alpha-substituent group can greatly inﬂuence the reactivity.21Heterogenous CatalystsReaction Mechanisms:A General Overview.Heteroge-neous acid and basic catalysts could be classiﬁed as Brönsted or Lewis catalysts,though in many cases both types of sites could be present and it is not easy to evaluate the relative importance of the two types of sites in the reaction.A detailed description of some reaction mechanisms can be found in the paper of Lotero et al.20Here for brevity’s sake,we will report only a general overview on reaction mechanisms of the different catalyst types.When homogeneous Brönsted basic catalysts,i.e.,NaOH,KOH,Na 2CO 3,were mixed with alcohol,the actual catalyst is formed.This is the alkoxide group:Na +OH -+CH 3OH f H 2O +CH 3O -Na +which attacks the carbonyl carbon atom of the triglyceride molecule.3,20Often an alkoxide (NaOCH 3,KOCH 3)is directly used as catalyst.A similar mechanism is operative in the case of a heteroge-neous basic Bronsted catalyst such as basic zeolite:20Also inthis case,the formed catalytic specie is a homogeneous alkoxide.In the case of heterogeneous basic Bronsted catalyst such as resin with quaternary ammonium functionality (QN +OH -),the positive counterions (organic ammonium groups),being bonded(11)Ono,T.,Yoshiharu,K.Process for producing lower alcohol esters or fatty acids.U.S.Patent 4,164,506,Aug 14,1979.(12)Fukuda,H.;Kondo,A.;Noda,H.J.Biosci.Bioeng.2001,92,405–416.(13)Haas,M.J.;Piazza,G.J.;Foglia,T.A.Lipid Biotechol.2002,587–598.(14)Kumari,V.;Shah,S.;Gupta,M.N.Energy Fuels 2007,21,368–372.(15)Di Serio,M.;Tesser,R.;Dimiccoli,M.;Cammarota,F.;Nastasi,M.;Santacesaria,E.J.Mol.Catal.A:Chem.2005,239,111–115.(16)Zhang,Y.;Dubè,M.A.;McLean,D.D.;Kates,M.Bioresour.Technol.2003,89,1–16.(17)Zhang,Y.;Dubè,M.A.;McLean,D.D.;Kates,M.Bioresour.Technol.2003,90,229–240.(18)Basu,H.N.;Norris,M.E.U.S.Patent 5,525,126,June 11,1996.(19)Siano,D.;Di Serio,M.;Tesser,R.;Dimmicoli,M.;Cammarota,F.;Santacesaria,E.;Siano,L.;Nastasi,M.Process for the production of esters from V egetables oils or animal fats.PCT No.WO2006/006033,Jan 19,2006.(20)Lotero,E.;Goodwin,J.G.,Jr.;Bruce,D.A.;Suwannakarn,K.;Liu,Y.;Lopez,D.E.Catalysis 2006,19,41–84.(21)Liu,Y.;Lotero,E.;Goodwin,J.G.,Jr.J.Catal.2006,243,221–228.208Energy &Fuels,Vol.22,No.1,2008Di Serio et al.directly to the support surface,electronically retain the catalytic anions on the solid surface:The reaction occurs betweenmethanol adsorbed on the cation and ester from the liquid (Eley–Rideal mechanism).The formation of alkoxide groups is also a fundamental step for heterogeneous basic Lewis catalyst.For example,in the case of ethylacetate transesteriﬁcation,catalyzed by MgO,the reaction occurs between the methanol molecules adsorbed on a magnesium oxide free basic sites and the ethyl acetate moleculesfrom the liquid phase (Eley–Rideal mechanism).22,23Both homogeneous Brönsted (H 2SO 4,p -toluensolfonic acid 5,20)and Lewis (metal acetate,10,15,18–20metal complexes 24)acid catalysts have been used in biodiesel synthesis,and both catalyze either transesteriﬁcation and esteriﬁcation reactions.25Brönsted acid catalysts are active mainly in esteriﬁcation reactions while Lewis acid catalysts are more active in transesteriﬁcation reactions (see,for example,Table 126).Table 1reports data of runs performed by using a series of small stainless steel vial reactors.Both the reagents (oil (FFA )0.2%w/w))2.0g,methanol )0.88g)and a speciﬁed amount of the catalyst were introduced into each reactor.All the reactors were then heated in a ventilated oven.The temperature of the oven was initially ﬁxed at 50°C for 14min and then increased at a rate of 20°C/min until the reaction temperature was reached,where the samples were kept for the ﬁxed reaction time.At the end of the reaction,the temperature was quenched by putting the vials in a cold bath.Experimental runs were also performed by adding oleic acid to the reaction mixture.Oleic acid has been chosen as a test molecule for simulating the behavior of FFA.The lead acetate (Lewis acid)has greater transesteriﬁcation activity than p -toluenesulfonic (Brønsted acid)acid,while on the contrary p -toluenesulfonic acid is more active than lead acetate in esteriﬁcation reactions.The lower yield obtained with lead acetate using an acid oil is justiﬁed by the strong deactivation of the Lewis catalyst due to the water formed in the esteriﬁcation reaction.15In both homogeneous and heterogeneous Brønsted acid catalysis,the mechanism pathways proceed through the protonation of the carbonyl group:increasing its electrophi-licity and rendering it more susceptible to alcohol nucleo-philic attack.21In the case of Naﬁon supported on silica (Naﬁon SAC-13),Lopez et al.27proposed a mechanistic pathway for triacetin transesteriﬁcation s a mechanism similar to that accepted for a homogeneous Brønsted acid catalyst.They found activation energy and reaction orders similar to the ones showed by sulfuric acid.27The reaction mechanism in esteriﬁcation reactions promoted by solid acid Brønsted catalysts is also similar to the homoge-neous one.28Liu et al.,28found that Naﬁon supported on silica has comparable turnover frequencies (TOF)to H 2SO 4and a similar reaction mechanism in esteriﬁcation of the liquid acetic acid with methanol.The reaction occurs via a single-site Eley–Rideal mechanism involving a nucleophilic attack between adsorbed carboxylic acid and unadsorbed alchohol as the rate-determining step.28The formation of a more electrophilic species also occurs with homogeneous and heterogeneous Lewis acid catalysts as the ﬁrst step in the reaction mechanism:15,29–31In this case,therate-determining step depends on the Lewis catalyst’s acid strength.After the Lewis complex formation (stage 1),the alcohol nucleophilic bonding (stage 2),and the new ester formation (stage 3),the new ester desorbs from the Lewis site (stage 4)and the cycle is repeated.If the strength of acidic sites is too high,the desorption of the product is not favored,(22)Dossin,T.F.;Reyniers,M.F.;Marin,G.B.Appl.Cat.B.2006,61,35–45.(23)Dossin,T.F.;Reyniers,M.F.;Berger,R.J.;Marin,G.B.Appl.Cat.B.En V iron.2006,67,136–148.(24)Abreu,F.R.;Lima,D.G.;Hamù,D.G.;Einloft,S.;Rubim,J.C.;Suarez,P.A.Z.J.Am.Oil Chem.Soc.2003,80,601–604.(25)López,D.E.;Suwannakarn,K.;Bruce,D.A.;Goodwin,J.G.,Jr.J.Cat.2007,247,43–50.(26)DiSerio,M.;Tesser,R.;Mandato,N.;Santacesaria,E.Unpublished data.(27)López,D.E.;Goodwin,J.G.,Jr.;Bruce,D.A.J.Cat.2007,245,381–391.(28)Liu,Y.;Lotero,E.;Goodwin,J.G.,Jr.J.Cat.2006,242,278–286.(29)Parshall,G.W.Ittel SI Homogeneous Catalysis:The Applications and Chemistry of Catalysis by Soluble Transition Metal ,2nd ed.;Wiley-Interscience:New York,2005.(30)Di Serio,M.;Apicella,B.;Grieco,G.;Iengo,P.;Fiocca,L.;Po,R.;Santacesaria,E.J.Mol.Cat.A.Chem.1998,130,233–240.(31)Bonelli,B.;Cozzolino,M.;Tesser,R.;Di Serio,M.;Piumetti,M.;Garrone,E.;Santacesaria,E.J.Cat.2007,246,293–300.Table 1.Oil )Soybean,8g;Methanol/Oil Molar Ratio )12:126catalyst initial FFA conc (%wt)reaction temp (°C)reaction time (min)cat (mol)FAME yield (%)ﬁnal FFA conc (%wt)uncatalyzed 180402uncatalyzed 20.5180602210.7Pb(Ac)218040 5.4710-592p -toluenesulfonic acid 18040 5.3510-529Pb(Ac)220.518060 5.3810-557 6.8p -toluenesulfonic acid20.5180606.4010-5481.1Catalysts for Biodiesel Production Energy &Fuels,Vol.22,No.1,2008209determining a slow reaction rate.15,29–31This mechanism was conﬁrmed for both homogeneous15,29,30and heterogeneous catalysts31by the observation that an optimal range of strength for Lewis acidic sites exists and that very strong Lewis acidic catalysts are less active in transesteriﬁcation reactions.15,29–31 Basic Catalysts.Gryglewicz32investigated the possibility of using alkaline-earth metal hydroxides,oxides,and alkoxides to catalyze the transesteriﬁction of rapeseed oil at methanol reﬂux temperature.He found that sodium hydroxide was the most active,barium hydroxide was slightly less active,and that calcium methoxide showed medium activity.The reaction rate was lowest when CaO powder was used as catalyst while magnesium oxide and calcium hydroxide showed no catalytic activity.32The high activity of barium hydroxide is due to its higher solubility in methanol with respect to other compounds. The order of reactivity Ca(OH)2<CaO<Ca(CH3O)2agrees with the Lewis basic theory:the methoxides of alkaline-earth metals are more basic than their oxides which are more basic than their hydroxides.32Table2reports some data about CaO catalytic performance.32,33The yield of biodiesel using CaO as a catalyst increases with increase in the temperature and methanol/oil molar ratio,especially in the case of the methanol supercritical state33,34s see Table3entries1–3.In the methanol supercritical state,good performances were obtained also with Ca(OH)2and CaCO334s see Table3entries4–6.Increases in CaO performances can be obtained using nanocrystalline calcium oxides.35The nanocrystalline calcium oxides(crystal size)20nm;speciﬁc surface area)90m2/g) give100%conversion of soybean oil at room temperature after 12h while the conversion obtained with commercial CaO (crystal size)43nm;speciﬁc surface area)1m2/g)is only 2%.35López Granados et al.36studied the activity of activated CaO as a catalyst in the production of biodiesel by the transesteri-ﬁcation of triglycerides with methanol.The active surface sites of CaO are poisoned by the atmospheric H2O and CO2.The catalytic activity of CaO can be improved if CaO is subjected to an activation treatment at high temperature(g700°C)before the reaction s to remove the main poisoning species(the carbonate groups)from the surface s and if the contact with atmospheric air is prevented after this treatment.36Even if the catalyst can be reused for several runs without signiﬁcant deactivation,dissolution of CaO does occur.The catalytic reaction is the result of the contribution of both heterogeneous and homogeneous catalysis for the formation of leached active species and further investigation is necessary to quantify this aspect.36The transesteriﬁcation rate can be increased using microwave energy,37,38because the microwave energy selectively energizes the catalyst’s interaction with the reactants.38Table4(entries1and2)reports results obtained with Ca(OH)238and Ba(OH)2.37The data of Mazzochia et al.37 conﬁrm that Ba(OH)2is not a completely heterogeneous catalyst. As a matter of fact,when the product obtained after reaction is not washed several times with distilled water,the resulting FAME and glycerine contain ca.0.06%and0.25%of barium, respectively.Good results in transesteriﬁcation of soybean oil were obtained using ZnO loaded Sr(NO3)2followed by calcination at873K for5h.39When the transesteriﬁcation reaction was carried out at reﬂux of methanol(65°C),with a12:1molar ratio of methanol to soybean oil and a catalyst amount of5wt %,the conversion of soybean oil was94.7%.39The SrO derived from thermal decomposition of Sr(NO3)2at high calcination temperatures is probably the main catalytically active specie.39 However,the used catalyst was signiﬁcantly deactivated and could not be directly reused for transesteriﬁcation.39Yang and Xie39explained the deactivation by the deposition of reactants and products on the active sites and/or by a transformation of the active sites and their interactions during the reaction. However,the leaching of SrO was not examined;notwithstand-ing,its high solubility in the reaction environment36is known. Sodium silicate catalyzes the transesteriﬁcation of oils with high rates at moderate temperatures(60–120°C)s even if no data on catalyst reusability was reported.38Also in this case, the use of microwave energy and high methanol/oil ratio greatly increases the performances s see Table4entries3and4. Corma et al.,40in a patent mainly devoted to the transesteri-ﬁcation of triglycerides with glycerol to prepare monoglycerides, claimed the possibility to use calcined hydrotalcites and magnesium oxides in promoting the transesteriﬁcation of triglycerides with monoalcohols,even if no examples or experimental data for this reaction are reported in the mentioned patent.Leclercq et al.41tested the use of commercial MgO/Al2O3 hydrotalcites and MgO(300m2/g)in the transesteriﬁcation of rapeseed oil.They found that MgO was more active than hydrotalcite s see Tables5and6entry1.On the other hand, Cantrell et al.,42successfully used calcined hydrotalcites in promoting the transesteriﬁcation of glycerol tributyrate with methanol at60°C.The rate increases steadily with Mg content, and the most active catalyst Al/(Mg+Al))0.25was10times more active than MgO.42Xie et al.,43for soybean oil transes-teriﬁcation at methanol reﬂux,found that the most active calcined hydrotalcite has again an atomic ratio Al/(Mg+Al) )0.25s see Table6entries2–4s and that a higher active solid is obtained by calcining it at500°C;see Table6entries3,5, and6.Di Serio et al.44and Siano et al.45showed the possibility(32)Gryglewicz,S.Bioresour.Technol.1999,70,249–253.(33)Demirbas,A.Energy Con V ers.Manage.2007,48,937–941.(34)Tateno T.,Sasaki T.Process for producing fatty acid fuels comprising fatty acids esters.U.S.Patent6,818,026,Nov16,2004.(35)Reddy,C.;Reddy,V.;Oshel,R.;Verkade,J.G.Energy Fuels2006, 20,1310–1314.(36)Lopez Granados,M.;Zafra Poves,M.D.;Martin Alonso,D.; Mariscal,R.;Cabello Galisteo,F.;Moreno Tost,R.;Santamaria,J.;Fierro, J.L.G.App.Cat.B.2007,73,317–326.(37)Mazzocchia,C.;Modica,G.;Nannicini,R.;Kaddouri,A.C.R. Chim.2004,7,601–605.(38)Portnoff,M.A.;Purta,D.A.;Nasta,M.A.;Zhang,J.Pourarian,F.Methods for producing biodiesel.PCT No.WO2006/002087,Jan5,2006.(39)Yang,Z.Q.;Xie,W.L.Fuel Process.Technol.2007,88,631–638.(40)Corma,A.,Iborra,S.,Miquel,S.,Primo Millo,J.Process and Catalysts for the Selective production of Esters of fatty Acids.PCT No WO98/56747,Dec17,1998.(41)Leclercq,E.;Finiels,A.;Moreau,C.J.Amer.Oil Chem.Soc.2006, 78,1161–1165.(42)Cantrell,D.G.;Gillie,L.J.;Lee,A.F.;Wilson,K.Appl.Catal., A2005,287,183–1990.(43)Xie,W.;Peng,H.;Chen,L.J.Mol.Cat.A.2006,246,24–32.(44)Di Serio,M.;Ledda,M.;Cozzolino,M.;Minutillo,G.;Tesser,R.; Santacesaria,E.Ind.Eng.Chem.Res.2006,45,3009–3014.Table2.FAME Yield Using CaO as Catalyst at15min ofReaction Timeref oilreactiontemp(°C)methanol/oilmolar ratiocat conc(%w/w)FAMEyield(%)32rapeseed methanol reﬂux 4.5:10.81033sunﬂower19241.1:1 3.050210Energy&Fuels,Vol.22,No.1,2008Di Serio et al.to use calcined hydrotalcites and MgO for industrial biodiesel production at moderately high temperature.High yields of methyl esters were obtained in1h of reaction time at180–200°C s see Tables5(entries2–3)and6(entry7).At least four different types of basic sites have been indentiﬁed on the surface of MgO and calcined hydrotalcite catalysts.44The strongest basic sites(superbasic)promote the transesteriﬁcation reaction also at very low temperatures(100°C),while the basic sites of medium strength require higher temperatures to promote the same reaction.44The experimental data reported show a correlation not only with the catalyst basicity but also with its structural texture.44However,the structural texture of the catalysts examined is dependent on both the precursor and the preparation method.44,46MgO catalyst used to promote transesteriﬁcation strongly increases the reaction rate in supercritical conditions,34as can be seen in Table3entry7.As vegetable oils,animal fats,and alcohols usually contain water,44the inﬂuence of the presence of water on MgO and calcined hydrotacite performances have also been investigated.44,45 Some runs have been performed at180°C in the presence of high water concentration(10000ppm).44The results show that the activity of both magnesium oxide and calcined hydrotalcite is not affected by the presence of an excess of water.44This lastﬁnding is relevant for industrial purposes,because the possibility to operate in the presence moisture reduces the raw material pretreatment costs and opens the possibility to use unreﬁned bioethanol.However,Oku et al.47showed that in a run performed at150°C with60g of triolein,20g of methanol,and2.5g of Mg/Al hydrotalcite after24h of reaction,a FAME yield of77was produced,but a very high concentration of Mg and Al ions were detected in the products(Mg17800ppm;Al6900ppm).So, the problems of catalyst leaching need more in-depth study to conﬁrm the possibility of using MgO and related hydrotalcites as industrial catalysts.Corma et al.48have reported that calcined Li/Al hydrotalcites are more active in glycerolysis of fatty acid methyl esters than the Mg/Al material(or MgO)due to their higher Lewis basicity. Starting from this observation,Shumaker et al.49studied the transesteriﬁcation of soybean oil to fatty acid methyl esters using a calcined Li/Al layered double hydroxide catalyst.It was found that,at the reﬂux temperature of methanol,near-quantitative conversion of the soybean oil was achieved at low catalyst loadings(2–3wt%)and short reaction times(∼2h).49Catalyst recycling runs showed that the catalyst maintained a high level(45)Siano,D.;Nastasi,M.;Santacesaria,E.;Di Serio,M.;Tesser,R.; Minutillo,G.;Ledda,M.;Tenore,T.Process for Producing esters from vegetable oils or animal fats using heterogeneous catalysts.PCT Application No WO2006/050925,May18,2006.(46)Choudhary,V.R.;Pandit,M.Y.Appl.Catal.1991,71,265–274.(47)Oku,T.;Nonoguchi,M.;Moriguchi,T.Method of producing of fatty alkyl esters and/or glycerine and fatty acid alkyl ester-containing composition.PCT Application No WO2005/021697,Mar10,2005.(48)Corma,A.;Hamid,S.B.A.;Iborra,S.;Velty,A.J.Catal.2005, 234,340–347.(49)Shumaker,J.L.;Crofcheck,C.;Tackett,S.A.;Santillan-Jimenez,E.;Crocker,M.Cat.Lett.2007,115,56–61.Table3.FAME Yield Using Basic Catalysts in Methanol Supercritical Conditionsentry ref oil catalystreactiontemp(°C)methanol/oilmolar ratioreacttime(min)cat conc(%w/w)FAMEyield(%)133sunﬂower CaO252 6.0:115 3.065 233sunﬂower CaO25241.1:115 3.099 334soybean CaO30039.3:1100.5897 434soybean CaCO325039.3:110 1.1487 534soybean CaCO330039.3:1100.6799 634soybean Ca(OH)230039.4:1100.6898 734soybean MgO30039.6:110 1.2991 parison of the Transesteriﬁcation Tests of Oil with Methyl Alcohol Carried out under Microwave Irradiationentry ref oil catalystreactiontemp(°C)methanol/oilmolar ratioreactiontime(min)cat conc(%w/w)FAMEyield(%)137rapeseed Ba(OH)2methanol reﬂux9:1150.597–98 238soybean Ca(OH)21006:120 2.081 338castor oil sodium silicate1206:110 1.570 438castor oil sodium silicate12019:110 1.5100Table5.FAME Yield Using MgO as Catalystentry ref oil surfaceareareactiontemp(°C)methanol/triglyceridesmolar ratioreactiontime(h)cat conc(%w/w)FAMEyield(%)141rapeseed300methanol reﬂux75:1221064 244soybean3618012:11 5.072 344soybean22918012:11 5.090Table6.FAME Yield Using Calcined MgO/Al2O3as Catalystentry ref oil Al/(Mg+Al)surfaceareacalcinationtemp(°C)reactiontemp(°C)methanol/oilmolarratioreactiontime(h)cat conc(%w/w)FAMEyield(%)141rapeseed0.30160450methanol reﬂux275:1221034 243soybean0.28500methanol reﬂux15:197.528 343soybean0.25500methanol reﬂux15:197.566 443soybean0.22500methanol reﬂux15:197.550 543soybean0.25450methanol reﬂux15:197.545 643soybean0.25600methanol reﬂux15:197.557 744soybean0.2514450018012:11 5.092 Catalysts for Biodiesel Production Energy&Fuels,Vol.22,No.1,2008211。

市政污泥与含氟污泥的环境土工特性比较分析

市政污泥与含氟污泥的环境土工特性比较分析王月香;陈茂林;丁建文【摘要】通过试验研究了市政污泥和含氟污泥的环境土工特性,并进行了对比分析,得出结论为:两种污泥的含水率、液限、塑限、液性指数、孔隙比、有机质等都很高,除了比重、密度外,市政污泥的各项指标较含氟污泥高;市政污泥溶液为酸性,含氟污泥为碱性;市政污泥中的重金属含量以Cu、Zn居多,而在含氟污泥中污染物为Cr、Sr、Zn、F;市政污泥中Cu的残渣态比例较高,Zn酸溶态比例较高;Cu、Zn的迁移性随溶液碱性增强而降低;含氟污泥中Sr的迁移性随溶液碱性增强而降低;含氟污泥中的氟元素以残渣态为主.Cr主要形态亦为残渣态,Cr的迁移性随着pH值的升高而降低.两种污泥的抗剪强度和渗透性都很低,其中含氟污泥略高,均不能满足填埋要求;两种污泥压缩性都很高,且市政污泥略高;两种污泥的压实性均差,压实效果不佳.【期刊名称】《工业安全与环保》【年(卷),期】2014(040)007【总页数】4页(P71-74)【关键词】市政污泥;含氟污泥;环境;土工【作者】王月香;陈茂林;丁建文【作者单位】苏州科技学院土木工程学院江苏苏州215011;东南大学岩土所南京210096;江苏苏净集团苏净环保有限公司江苏苏州215011;东南大学岩土所南京210096【正文语种】中文0 引言污泥初始的物理化学特征以及工程力学特性是对其采取相应处理技术和最终处置方式的基础。

市政污泥和含氟污泥是两种代表性污泥，两者的初始特性都有较大差异，因此有必要弄清楚两者的联系和区别，从而为后续研究工作奠定基础。

本文对两种污泥的含水率、密度、比重、有机质含量等物理性质，对重金属含量、形态、pH值等化学性质，对抗剪强度、压缩模量、固结系数、渗透系数等力学特性进行了相关的试验与测试计算，对全面了解市政污泥和含氟污泥的环境土工特性有着重要的参考价值。

1 样品及测试1.1 样品市政污泥(SS)取自南京某污水处理厂，机械压滤脱水，为灰黑色半流态物质。

地质词典

英文地质书刊中常用词组Aa bit of 一点，少量的above all 尤其是，最重要的是according as 依照，随。

而定according to 依照，根据account for 说明，解释act as 起。

作用，担任act（up）on对。

起作用a few 有几个，有一些after all 毕竟，终究a good（great）deal of 很多a good（great）many of 很多agree to 答应，承认agree with 同意。

的意见，与。

一致a little 一点；一会儿all at once 突然all but差不多，几乎，都all over 到处；完全；结束all over the world全世界all the same完全一样，依然all the time始终，一直all the while始终，一直all through从头到尾，始终along with与。

一道；随着a lot of大量，许多amount to总计，等于and so forth等等and so on等等and the like等等answer to符合，与。

一致a number of若干apart from 除。

外，且不说as a matter of course当然的事as a matter of fact 实际上，其实as a result结果as a result of由于。

结果as a rule通常as a whole整个说来as concerns至于，关于as early as 早在a series of一系列as far as远至，到。

程度；尽。

所as far as。

be concered就。

而论，对。

来说as far as。

goes就。

而论as far back as早在。

（就），远在。

（就）as follows 如下，如下所述as for至于，就。

而论as good as和。

孟德尔随机化extract clump access代码 -回复

孟德尔随机化extract clump access代码-回复[孟德尔随机化extract clump access代码]孟德尔随机化(或称为Fisher-互换)是一种用于实验证据收集和分析的方法，旨在消除由于无法控制某些参数而引起的偏见。

这种方法被广泛用于生物学、医学和社会科学研究中。

其中一个常见的应用领域是评估新药的疗效。

在这篇文章中，我们将研究如何使用孟德尔随机化方法来提取类群访问数据。

假设我们正在进行一个实验，想要比较两种不同访问方式下网站用户的行为。

我们将采用孟德尔随机化方法来确保我们的实验结果是可靠的并且没有偏见。

首先，我们需要准备我们的实验数据。

我们将创建一个包含用户ID、访问方式和用户行为的数据集。

对于这个示例，我们将假设我们有1000个用户参与了实验，其中500个使用A方式访问，500个使用B方式访问。

接下来，我们需要实现孟德尔随机化方法的代码来提取类群访问数据。

以下是一个例子：pythonimport randomdef extract_clump_access(data, clump_size):clump_a = []clump_b = []for user in data:access_type = user['access_type']if access_type == 'A':clump_a.append(user)elif access_type == 'B':clump_b.append(user)random.shuffle(clump_a)random.shuffle(clump_b)clump_a = clump_a[:clump_size]clump_b = clump_b[:clump_size]return clump_a, clump_b# Usage exampledata = [{'user_id': 1, 'access_type': 'A', 'behavior': 'click'},{'user_id': 2, 'access_type': 'A', 'behavior': 'browse'},{'user_id': 3, 'access_type': 'B', 'behavior': 'purchase'},{'user_id': 4, 'access_type': 'B', 'behavior': 'click'}]clump_a, clump_b = extract_clump_access(data, 100)在上述代码中，我们首先创建了两个空的列表来存储根据访问方式提取的类群数据。

沉积物中重金属形态分析方法研究进展

沉积物中重金属形态分析方法研究进展冯素萍1　鞠　莉1　沈　永1　裘　娜1　李　鑫1　祝培明1　王　伟3(1.山东大学环境学院,济南　250100;　2.山东省地质科学实验研究院,济南　250013;　3.枣庄市环境监测站,枣庄　277101) 摘要　介绍近年来国内外对沉积物中重金属的研究概况,以及重金属形态分离方法和监测方法的最新进展,对国内外常用的沉积物中重金属的形态分析提取方法如Tessier法、Forstner法和BCR法进行了比较,概述了重金属形态分离检测方法。

关键词　沉积物　重金属　形态分析近年来随着工农业的发展,各种工业废液排入水体,使水体中重金属的含量越来越高,严重影响着人类及其它生物的健康与生存。

20世纪50年代日本发生的由汞污染引起的“水俣病”事件和由镉污染引起的“骨痛病”事件,以及在欧洲某些国家陆续发生的由重金属污染而导致的一系列严重生态后果,引起了人们对重金属污染的重视。

重金属污染物具有较为复杂的化学性质和极强致毒性。

自20世纪70年代以来,重金属污染与防治的研究工作备受关注[1]。

目前,重金属污染物已被众多国家列为环境优先污染物。

我国列入环境优先污染物黑名单的重金属有A s、Be、Cd、Cr、Cu、Pb、Hg、N i和Ti[2]。

重金属污染物的化学行为和生态效应复杂,对环境存在着难于治理的潜在危害,其物化行为多具有可逆性,同时在适宜条件下,又具有相对稳定性。

大多数重金属化合物为非降解型有毒物质,生态效应的浓缩和累积作用使微量重金属产生生物毒性,沿食物链被动植物所吸收、富集,最终成为生命体积累和慢性中毒的源场。

环境中特定重金属元素的生物可给性及在生物体中的积累能力,以及对生物毒性与该元素在环境中存在的物理形态及化学形态密切相关。

重金属的总量往往很难表征其污染特性和危害,水体沉积物中重金属的迁移转化规律、毒性以及可能产生的环境危害更大程度上取决于其赋存形态[3],如Cr(III)是人体必需的,而Cr(V I)具有高毒性,其生理毒性比Cr(III)高100倍;A s(III)的毒性高于As(V);游离态的铜对水生生物的毒性大于与有机体结合的络合态铜,其络合物越稳定,毒性就越低。