美国EPA3546 新方法---微波快速溶剂萃取技术
利用快速溶剂萃取(ASE)法检测水果和蔬菜中有机氯农药残留
利用快速溶剂萃取(ASE)法检测水果和蔬菜中有机氯农药残留常春艳;王云凤;葛宝坤;刘晹【期刊名称】《口岸卫生控制》【年(卷),期】2004(009)006【摘要】快速溶剂萃取(ASE)法是一种全新的处理固体、半固体样品的方法，该法是在较高温度(50℃-200℃)和压力条件(10．3Mpa-20．6Mpa)下，用有机溶剂萃取。
它的突出优点是有机溶剂用量少、快速和回收率高，已成为样品前处理最佳方法之一，并被美国EPA(环保局)选定为推荐的标准方法(标准方法编号EPA3545)。
快速溶剂萃取仪ASE使得样品的准备变成自动流程，已广泛用于环境、药物、食品和其他样品的前处理，特别是农药残留量的分析。
【总页数】2页(P25-26)【作者】常春艳;王云凤;葛宝坤;刘晹【作者单位】天津出入境检验检疫局,300456;天津出入境检验检疫局,300456;天津出入境检验检疫局,300456;天津出入境检验检疫局,300456【正文语种】中文【中图分类】R155.54【相关文献】1.气相色谱法检测蔬菜水果中6种有机氯农药残留 [J], 郑艳春;刘春来;刘照清;李拥兵;李素平2.加速溶剂萃取(ASE)-GC-MS/MS法检测土壤中的戊菌隆、哒菌酮、苯锈啶、咯喹酮和三环唑5种杀菌剂残留 [J], 克选3.全自动快速溶剂萃取-气相色谱法测定蔬菜、水果中29种有机磷农药 [J], 高慧;汪洋;王敏;邢燕;刘婷婷4.蔬菜水果中25种有机氯农药残留快速检测方法 [J], 刘长武;刘凤枝;翟广书;刘潇威;买光熙;陈勇;王一茹5.缓冲QuEChERS法提取气相色谱火焰光度检测法快速测定水果蔬菜中39种有机磷农药残留 [J], 张秀尧;蔡欣欣;陈珞洛;郑三燕因版权原因，仅展示原文概要，查看原文内容请购买。
微波协助萃取的方法原理
微波协助萃取的方法原理
微波协助萃取（Microwave-assisted extraction, MAE）是一种新的样品萃取技术，
能够在短时间内从固体样品中萃取目标化合物。
MAE技术在环境、农业、生物和食品科学
中广泛应用，其优点主要表现在提高提取效率、缩短提取时间和减少有毒有害深度溶剂的
使用等方面。
MAE是利用微波电磁波的加热作用，在特定条件下改变样品中化合物的物理状态，改
善物质的扩散速度和提取速度，从而加速萃取过程。
具体来说，MAE须知样品与溶剂被转
移到微波反应瓶，该瓶能够吸收微波发射的能量，使溶剂快速加热到超过溶解化合物的温度，从而提取化合物。
MAE技术的优点在于其高效、快速和可靠的萃取效果。
相比传统的萃取方法，MAE能够显著缩短提取时间，提高提取效率和减少深度溶剂的使用量。
此外，MAE也能够获得高温、高压、高速度和高分辨率的萃取效果，同时减少了样品微生物污染的风险。
MAE技术的萃取效率受到很多因素的影响，比如微波功率、萃取时间、溶剂种类和比例、固相萃取（SPE）纯化等。
其中，微波功率是最重要的因素之一，通常情况下，微波功率越高，提取效果也就越好。
而萃取时间和溶剂种类比例则需根据具体实验条件灵活调整，以达到最佳的萃取效果。
最后需要注意的是，MAE技术的萃取过程必须进行完整的控制和监测，避免微波加热
过程中发生了爆炸或雷击事故，还需要谨慎选择微波瓶、溶剂和电器等设备，保证实验的
安全性和准确性。
EPA3546方法以及其官方标准仪器
EPA3546方法以及其官方标准仪器/v07/tool/category/category_01_012.htmlＭＡＲＳＸ微波快速溶剂萃取仪Microwave Accelerated Solvent Extraction为气/液相色谱等进行样品制备标准方法：EPA3546：微波应用于挥发性有机物和半挥发性有机物的萃取。
ASTM D5765方法:密闭式微波加热法萃取土壤及沉积物中的总石油碳氢化合物。
ASTM D6010方法:密闭式微波加热法萃取固体材料中的有机物前言：MARSX由于其1/120秒ACCUPOWER变频磁控管+高频闭环反馈+非脉冲连续微波三项新技术的应用,获98年度全美R—D100大奖。
最特出的性能就是智能化专家系统和高精确过程控制反应，MARSX利用微波精确辐射激发极性分子，并且通过内置CARBOFLON加热和极化非极性试剂，辅之精确温压控制，温压推升可达温度300℃，压力1500psi。
实现快速完全的精确溶剂萃取样品制备。
大大提高了现代气/液相色谱测定精度和效率。
试剂量只为常规萃取的1/15左右， 10g样品萃取每次仅用12分钟，且每批处理达到40个样的能力，效率比SOXHLET快160倍。
而且免除了常规快速溶剂萃取技术的干燥样品前处理。
使样品准备比常规方法更少试剂、更快、更安全。
它采用全程一体化内置电脑控制，智能化操作。
是20年来利用微波能快速，高效和精确进行样品制备和化学反应研究的一标志性进步。
选择MARSX微波快速溶剂萃取的理由：1)微波法回收率普遍比其他超出20%； 2)溶剂用量少10g样品仅需15mL溶剂；3)批处理量达14-40个样品； 6) 完成一次萃取时间只需5～15分钟；5)极性和非极性溶剂皆宜无限制； 7)每罐50-100mL容积样品量10-50g；微波的量子能级属于范德华力（分子间作用力）的范畴，其能量本身不会破坏分子结构，但能使分子产生高速偶极旋转，而且辅以高温和高压可更容易从基体快速分离被分析物质，迅速解除基质与被分析物间的分子间作用力，迫使被分析物从基质中解析并快速进入溶剂。
微波萃取在环保中的应用
微波萃取技术在环境分析中的应用张明祥（美国CEM公司，北京，100013）摘要：本文介绍了微波萃取的基本原理，并综述了微波萃取技术在环境分析中的应用，主要包括微波萃取土壤中有机污染物（PAHs，TPHs，有机磷农药，有机氯农药以及重金属等），阐述了微波萃取技术是环境分析中萃取污染物的好方法。
关键词：微波萃取环境分析土壤有机污染物前言从古时，人们就开始致力于将一种物质从另外一种物质中提取出来，但是那时候还缺乏科学的提取方法。
自从化学提取法建立起来后，才从效率和速度上得到本质的提高。
但是即使在今天，从混合物中分离、富集依然是一件费力费时的工作，特别是在复杂环境样品分析应用中，还是碰到了相当的困难。
环境分析最关键的步骤之一就是样品的预处理，即从采集到的环境样品基体中（如废水、土壤、植物、食品、饲料等）提取出待测分析组分。
多年来人们一直在探索速度快、消耗少、效率高且重复性好的提取方法，从传统的溶剂振荡萃取、索氏提取，超声提取到新近发展起来的快速溶剂萃取和超临界萃取，这些技术由于成本和效率等问题，在应用中都存在了一定的局限性，而80年代中期开始发展起来的微波萃取技术（Microwave Extraction Method）表现出了巨大应用潜力和良好发展前景，无疑成为了萃取技术中的佼佼者。
微波萃取技术起步较微波消解技术晚，还处于初始阶段[1]。
微波消解应用得到充分验证以后，N. Gedye等人于1986年将微波技术应用于有机化合物萃取，他们把将样品放于普通家用微波炉中，通过功率/时间模式激发微波，几分钟就能萃取得到了传统加热需要几个小时甚至十几个小时才能得到的分析物[2]。
从此微波辐射技术应用研究激发了人们的兴趣，逐渐从消解应用发展到了萃取应用。
上世纪90年代，由加拿大环境保护部和美国CEM公司经过多年的研究，开发了新一代的微波萃取系统（MARSX），该系统采用了能量最小化技术，有效的防止了萃取物的分解，并提高了萃取回收率和重现行，并经过美国加州环保局对MARSX认证后，批准MARSX作为唯一标准萃取仪器。
美国EPA3546 新方法---微波快速溶剂萃取技术
美国EPA3546新方法---微波快速溶剂萃取技术刘伟张明祥杨海鹏（美国CEM公司，北京，100013）摘要：由加拿大环保局和美国CEM共同开发的MARSX快速微波溶剂萃取技术，是世界上唯一专利的微波萃取技术，也是唯一符合美国EPA3546方法的仪器。
MARSX获98年度全美R&D100大奖，低功率先行非脉冲微波磁控管技术实现连续高精确过程控制反应，MARSX利用闭环反馈控制技术，通过高精度高频率的温压控制系统精确调节微波能量输出激发极性试剂，并且内置CARBOFLON加热和极化非极性试剂，实现了快速完全的样品萃取制备，大大提高了现代气/液相色谱测定精度和效率。
其主要特点是: 快速, 安全，批量大，样品量大，节省溶剂，污染小。
前言样品预处理是样品分析过程中最关键、最耗时的环节。
在现代化实验室高度重视速度和效率的今天，探索快速、高效、简便、自动化的样品预处理新方法已成为当代分析化学的前沿课题和重要研究方向之一。
萃取是分离和提纯物质的一种常用方法，为GC、HPLC等有机分析方法提供样品前处理。
传统的萃取方法由于费时、费试剂、效率低、重现性差等缺点,已不能满足分析发展的需要,于是先后出现了微波辅助萃取（MAE）、超临界流体萃取(SFE)和加速溶剂萃取（ASE）等萃取方法。
但由于技术、成本和效率等问题，一些萃取方法在使用中受到了限制，而微波萃取则克服了以上的缺点, 表现出了巨大的应用潜力和良好的发展前景。
自从1986年匈牙利学者Ganzler提出了微波萃取法并从土壤、种子、食品、饲料中萃取分离化合物以来[1]，微波萃取技术以高效、低耗、无污染，成为近年来萃取技术的佼佼者,被誉为“绿色”萃取技术。
微波是指频率为300到300 000MHz的电磁波，介于红外线和无线电波之间。
民用微波频率一般采用2450MHz，所对应能量大约为0.96J/mol，微波的量子能级属于范德华力（分子间作用力）的范畴，与化合物键能相差甚远[2]。
微波萃取技术
微波萃取技术节选自：郭振库金钦汉《微波萃取技术》（吉林大学化学系，长春，130023）摘要：微波萃取技术在有机污染物和有害金属分离的研究和应用方面出现了令人鼓舞的进展。
微波萃取方法具有方便、快速、试剂消耗低、回收率高和可用水作萃取溶剂的优点。
本综述介绍了微波萃取技术的原理、方法、设备和应用研究现状。
关键词：微波萃取技术设备方法综述一、概述现在，绝大多数的分析样品需要使用原子吸收光谱仪（AAS）、电感耦合等离子体发射光谱仪（ICP-AES）、气/液相色谱仪（GC/LC）、质谱仪、分子光谱仪等进行其中成分或元素的测定。
这些检测仪器一般都需用均匀液体样品，因此需要对原始样品进行消解、萃取、抽提或分离，然后才可能用上述仪器加以测定。
目前，常规样品萃取方法有分液漏斗法、超声萃取法或Soxhlet（索氏）提取法。
这些萃取法一般要用几小时或一天的时间，有些样品所需的萃取时间更长。
这些常规前处理方法不仅制样时间长，试剂用量大并对环境造成一定程度的污染，而且准确性和精密性已经不适应现代快速测定的要求。
此外，常规前处理方法长的制样时间，不能满足需要确定样品有效成分组成和结构的分析研究要求。
自Ganzler等人[1]报导用微波加热促进溶剂萃取污染土壤中的有机化合物以来，分析样品的微波萃取法由于萃取时间短、选择性好、回收率高、试剂用量少、污染低、可用水作萃取剂[2]的优点和可自动控制制样条件等而得到了分析工作人员的认同[3]，因而在设备研究、应用开发、机理探讨方面均有可喜的研究报导。
虽然微波萃取土壤中的有机污染化合物已有标准方法EPA3546[4]，但就目前而言，微波萃取的应用对象还比较少，与微波消解技术相比，微波萃取技术及其应用研究工作还处于最初的阶段[5]，微波萃取法还是一种相对年轻的样品处理方法[6]。
要使微波萃取法成为一个分析样品制备的常规方法，还需要做更多的技术研究和应用研究工作。
粮食、蔬菜、水果、茶叶、咖啡豆、中药、化妆品和乳制品是日常生活中的必需品，这些商品的品质和有害物质检验，样品数量多，要求快速测定，这是微波萃取技术最有应用前景的领域。
MARSX微波快速溶剂萃取仪教案资料
M A R S X微波快速溶剂萃取仪ＭＡＲＳＸ微波快速溶剂萃取仪Microwave Accelerated Solvent Extraction为气/液相色谱等进行样品制备标准方法：EPA3546：微波应用于挥发性有机物和半挥发性有机物的萃取。
ASTM D5765方法:密闭式微波加热法萃取土壤及沉积物中的总石油碳氢化合物。
ASTM D6010方法:密闭式微波加热法萃取固体材料中的有机物前言：MARSX由于其1/120秒ACCUPOWER变频磁控管+高频闭环反馈+非脉冲连续微波三项新技术的应用,获98年度全美R—D100大奖。
最突出的性能就是智能化专家系统和高精确过程控制反应，MARSX利用微波精确辐射激发极性分子，并且通过内置CARBOFLON加热和极化非极性试剂，辅之精确温压控制，温压推升可达温度300℃，压力1500psi。
实现快速完全的精确溶剂萃取样品制备。
大大提高了现代气/液相色谱测定精度和效率。
试剂量只为常规萃取的1/15左右， 10g样品萃取每次仅用12分钟，且每批处理达到40个样的能力，效率比SOXHLET快160倍。
而且免除了常规快速溶剂萃取技术的干燥样品前处理。
使样品准备比常规方法更少试剂、更快、更安全。
它采用全程一体化内置电脑控制，智能化操作。
是20年来利用微波能快速，高效和精确进行样品制备和化学反应研究的一标志性进步。
选择MARSX微波快速溶剂萃取的理由：1)微波法回收率普遍比其他超出20%；2)溶剂用量少10g样品仅需15mL溶剂；3)批处理量达14-40个样品；4极性和非极性溶剂皆宜无限制；5) 完成一次萃取时间只需5～15分钟；6)每罐50-100mL容积样品量10-50g；微波的量子能级属于范德华力（分子间作用力）的范畴，其能量本身不会破坏分子结构，但能使分子产生高速偶极旋转，而且辅以高温和高压可更容易从基体快速分离被分析物质，迅速解除基质与被分析物间的分子间作用力，迫使被分析物从基质中解析并快速进入溶剂。
epa3546
METHOD 3546MICROWAVE EXTRACTION1.0SCOPE AND APPLICATION1.1Method 3546 is a procedure for extracting water insoluble or slightly water soluble organic compounds from soils, clays, sediments, sludges, and solid wastes. The method was developed and validated on commercially-available solvent extraction systems. The procedure uses microwave energy to produce elevated temperature and pressure conditions (i.e., 100 -115E C and 50 - 175 psi) in a closed vessel containing the sample and organic solvent(s) to achieve analyte recoveries equivalent to those from Soxhlet extraction (Method 3540), using less solvent and taking significantly less time than the Soxhlet procedure. Other systems and other types of vessels may be used, provided that the analyst can demonstrate appropriate performance for a specific application.1.2This method is applicable to the extraction of semivolatile organic compounds, organophosphorus pesticides, organochlorine pesticides, chlorinated herbicides, phenoxyacid herbicides, substituted phenols, PCBs, and PCDDs/PCDFs, which may then be analyzed by a variety of chromatographic procedures. The method may also be applicable for the extraction of additional target analytes, provided that the analyst demonstrates adequate performance for the intended application (see Method 3500 and Chapter Two).1.3This method has been validated for solid matrices containing 50 to 10,000 µg/kg of semivolatile organic compounds, 250 to 2,500 µg/kg of organophosphorus pesticides, 10 to 5,000 µg/kg of organochlorine pesticides and chlorinated herbicides, 50 to 2,500 µg/kg of substituted phenols, 100 to 5,000 µg/kg of phenoxyacid herbicides, 1 to 5,000 µg/kg of PCBs, and 10 to 6000 ng/kg of PCDDs/PCDFs. The method may be applicable to samples containing these analytes at higher concentrations and may be employed after adequate performance has been demonstrated for the concentrations of interest (see Method 3500).1.4This method only is applicable to solid samples with small particle sizes. If practical, soil/sediment samples may be air-dried and ground to a fine powder prior to extraction. Alternatively, if worker safety or the loss of analytes during drying is a concern,soil/sediment samples may be mixed with anhydrous sodium sulfate or pelletized diatomaceous earth. The total mass of material to be prepared depends on the specifications of the determinative method and the sensitivity required for the analysis, but 2 - 20 g of material are usually necessary and can be accommodated by this extraction procedure.1.5This method has been validated using a solvent mixture of hexane and acetone (1:1) from matrices such as soil, glass-fibers and sand. Other solvent systems may be employed, provided that adequate performance can be demonstrated for the analytes of interest (see. Sec. 7.4).1.6Prior to employing this method, analysts are advised to consult the base method for each type of procedure that may be employed in the overall analysis (e.g., Methods 3500, 3600, 5000, and 8000) for additional information on quality control procedures, development of3546-1Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IVQC acceptance criteria, calculations, and general guidance. Analysts also should consult the disclaimer statement at the front of the manual and the information in Chapter Two, Sec. 2.1, for guidance on the intended flexibility in the choice of methods, apparatus, materials, reagents, and supplies, and on the responsibilities of the analyst for demonstrating that the techniques employed are appropriate for the analytes of interest, in the matrix of interest, and at the levels of concern.In addition, analysts and data users are advised that, except where explicitly specified in a regulation, the use of SW-846 methods is not mandatory in response to Federal testing requirements. The information contained in this method is provided by EPA as guidance to be used by the analyst and the regulated community in making judgments necessary to generate results that meet the data quality objectives for the intended application.1.7This method is restricted to use by or under the supervision of trained analysts. Each analyst must demonstrate the ability to generate acceptable results with this method.2.0SUMMARY OF METHOD2.1Samples are prepared for extraction by grinding to a powder and loaded into the extraction vessel.2.2The appropriate solvent system is added to the vessel and sealed.2.3The extraction vessel containing the sample and solvent system is heated to the extraction temperature (see Sec. 11.9) and extracted for 10 minutes (or as recommended by the instrument manufacturer).2.4The mixture is allowed to cool. The vessel is opened and the contents are filtered. The solid material is rinsed and the various solvent fractions are combined.2.5The extract may be concentrated, if necessary, and, as needed, exchanged into a solvent compatible with the cleanup or determinative procedure being employed.3.0DEFINITIONSSee Sec. 5.0 of Chapter 1 and the manufacturer’s instructions for definitions associated with this analytical procedure.4.0INTERFERENCES4.1Refer to Method 3500.4.2If necessary, Florisil and/or sulfur cleanup procedures may be employed. In such cases, proceed with Method 3620 and/or Method 3660.3546-2Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IV5.0SAFETYThe use of solvents combined with the operational parameters associated with this method will give rise to relatively elevated temperature and pressure conditions in the extraction vessels that can present potential safety concerns in the laboratory. Common sense laboratory practices can be employed to minimize these concerns. However, the following sections describe additional steps that should be taken.5.1The extraction vessels are at elevated temperatures and pressure after the extraction stage. Allow the vessels to cool before opening (the use of a water bath is recommended for this purpose) and always monitor the temperature and pressure by re-connecting the control vessel to the apparatus prior to opening the vessels5.2During the heating step, some solvent vapors may escape through the vessel liner/seal cover. Follow the manufacturer's directions regarding the vessel assembly and instrument setup to prevent release of solvent vapors to the laboratory atmosphere.5.3The instrument may contain flammable vapor sensors and should be operated with all covers in place and doors closed to ensure proper operation of the sensors. If so equipped, follow the manufacturer's directions regarding replacement of extraction vessel seals when frequent vapor leaks are detected.6.0EQUIPMENT AND SUPPLIESThe mention of trade names or commercial products in this manual is for illustrative purposes only, and does not constitute an endorsement or exclusive recommendation for use by EPA. The products and instrument settings cited in SW-846 methods represent those products and settings used during method development or subsequently evaluated by the Agency. Glassware, reagents, supplies, equipment, and settings other than those listed in this manual may be employed provided that method performance appropriate for the intended RCRA application has been documented as described in Sec. 2.1 of Chapter Two.6.1Microwave solvent extraction apparatus6.1.1The temperature performance requirements necessitate that themicrowave extraction system be capable of sensing the temperature to within ± 2.5E C and automatically adjusting the microwave field output power within 2 seconds ofsensing. Temperature sensors should be accurate to ± 2E C. Temperature feedbackcontrol provides the primary performance mechanism for the method.6.1.2Microwave extraction vessels are needed. Vessels are available thatcan accommodate 1-g to 20-g samples. Vessels should be transparent to microwaveenergy, relatively inert to reagents and sample components, and capable of withstanding the temperature and pressure requirements (minimum conditions of 200E C and 200 psi) necessary to perform this procedure. Follow the manufacturer’s instructions regarding cleaning, handling, and sealing the vessels.3546-3Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IV3546-4Draft Revision 0September 1999Pre-release version - This method has NOT been released by OSW as part of Update IV 6.2Apparatus for determining percent dry weight6.2.1Drying oven 6.2.2Desiccator 6.2.3Crucibles - porcelain or disposable aluminum6.3Apparatus for grinding - capable of reducing particle size to < 1 mm.6.4Analytical balance - capable to weighing to 0.01 g.6.5Apparatus for separating sample from solvent extract6.5.1Glass funnels 6.5.2Filter paper 6.5.3Pasteur pipettes6.6Vials for collection of extracts - 40-mL or 60-mL, or other appropriate volume, pre-cleaned, open top screw-cap with PTFE-lined silicone septum..7.0REAGENTS AND STANDARDS7.1Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.7.2Organic-free reagent water. All references to water in this method refer toorganic-free reagent water as defined in Chapter One.7.3Drying agents7.3.1Sodium sulfate (granular anhydrous), Na 2SO 4.7.3.2Pelletized diatomaceous earth.7.3.3The drying agents should be purified by heating at 400E C for 4 hours ina shallow tray, or by extraction with methylene chloride. If extraction with methylene chloride is employed, then a reagent blank should be prepared to demonstrate that the drying agent is free of interferences.7.4Extraction solventsThis method has been validated using a 1:1 mixture of hexane and acetone from matrices such as soil, glass-fibers, and sand. Other solvent systems may have applicability in microwave extraction, provided that at least one component absorbs microwave energy.The choice of extraction solvent will depend on the analytes of interest and no single solvent is universally applicable to all analyte groups. Whatever solvent system is employed, including those specifically listed in this method, the analyst must demonstrate adequate performance for the analytes of interest, at the levels of interest. At a minimum, such a demonstration will encompass the initial demonstration of proficiency described in Sec. 8.2 of Method 3500, using a clean reference matrix. Method 8000 describes procedures that may be used to develop performance criteria for such demonstrations as well as for matrix spike and laboratory control sample results.Hexane is a water-immiscible solvent and acetone is a water-miscible solvent. The purpose of the water-miscible solvent is to facilitate the extraction of wet solids by allowing the mixed solvent to penetrate the layer of water of the surface of the solid particles. The water-immiscible solvent extracts organics compounds with similar polarities. The polarity of acetone may also help extract polar analytes in mixed solvent systems.All solvents should be pesticide quality or equivalent. Solvents may be degassed prior to use.8.0SAMPLE COLLECTION, PRESERVATION, AND HANDLING8.1See the introductory material to this Chapter, Organic Analytes, Section 4.1.8.2Solid samples to be extracted by this procedure should be collected and stored as any other solid samples containing semivolatile organics.9.0QUALITY CONTROL9.1Refer to Chapter One and Method 8000 for specific Quality Control procedures and to Method 3500 for sample preparation quality control procedures.9.2Before processing any samples, the analyst should demonstrate that all parts of the equipment in contact with the sample and reagents are interference-free. This is accomplished through the analysis of a solid matrix method blank (e.g., clean sand). Each time samples are extracted, and when there is a change in reagents, a method blank should be prepared and analyzed for the compounds of interest as a safeguard against chronic laboratory contamination. Any method blanks, matrix spike samples, or replicate samples should be subjected to the same analytical procedures (see Sec. 11.0) as those used on actual samples.9.3All instrument operating conditions should be recorded.3546-5Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IV9.4Surrogate standards should be added to samples when listed in the appropriate determinative method.10.0CALIBRATION AND STANDARDIZATIONThere are no calibration or standardization steps associated with this sample extraction procedure other than establishing the extraction conditions in Section 11.9.11.0PROCEDURE11.1Sample preparationThe sample preparation steps vary with the type of sample to be extracted, as described below. Where practical, samples should be air-dried and ground to a fine powder before extraction. However, where such steps are not practical because of concerns about loss of the more volatile analytes or potential contamination of the laboratory from high concentration samples, samples may be mixed with a drying agent such as sodium sulfate or pelletized diatomaceous earth prior to extraction.11.1.1Sediment/soil samplesDecant and discard any water layer on a sediment sample. Mix the sample thoroughly, especially composited samples. Discard any foreign objects such as sticks, leaves, and rocks. Air dry the sample at room temperature for 48 hours in a glass tray or on hexane-rinsed aluminum foil. Alternatively, mix the sample with an equal volume of anhydrous sodium sulfate or pelletized diatomaceous earth until a free-flowing powder is obtained.NOTE:Dry, finely-ground soil/sediment allows the best extraction efficiency fornonvolatile, nonpolar organics, e.g., 4,4'-DDT, PCBs, etc. Air-drying may not beappropriate for the analysis of the more volatile organochlorine pesticides (e.g.,the BHCs) or the more volatile of the semivolatile organics because of lossesduring the drying process. Worker safety may be an issue with the drying ofsoils containing PCDDs/PCDFs as well.NOTE:Drying should always be performed in a hood, to avoid contamination of the laboratory.11.1.2Waste samplesMultiphase waste samples must be prepared by the phase separation method in Chapter Two before extraction. This extraction procedure is for solids only.11.1.3Dry sediment/soil and dry waste samples amenable to grinding3546-6Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IV3546-7Draft Revision 0September 1999Pre-release version - This method has NOT been released by OSW as part of Update IV %dry weight 'g of dry sample g of samplex 100Grind or otherwise reduce the particle size of the waste so that it either passesthrough a 1-mm sieve or can be extruded through a 1-mm hole. Disassemble grinder between samples, according to manufacturer's instructions, and decontaminate with soap and water, followed by acetone and hexane rinses. The notes in Sec. 11.1.1 also apply to the grinding process.11.1.4Gummy, fibrous, or oily materials not amenable to grindingCut, shred, or otherwise reduce in size these samples to allow mixing andmaximum exposure of the sample surfaces for the extraction. The analyst may addanhydrous sodium sulfate, pelletized diatomaceous earth, sand, or other clean, dryreagents to the sample to make it more amenable to grinding.11.2Determination of percent dry weightWhen sample results are to be calculated on a dry weight basis, a second portion of sample should be weighed at the same time as the portion used for analytical determination.WARNING:The drying oven should be contained in a hood or vented. Significant laboratorycontamination may result from drying a heavily contaminated sample.11.2.1Immediately after weighing the sample for extraction, weigh 5-10 g of thesample into a tared crucible. Dry this aliquot overnight at 105E C. Allow to cool in adesiccator before weighing.11.2.2Calculate the % dry weight as follows:11.3Grind a sufficient weight of the dried sample from Sec. 11.1 to yield the sample weight needed for the determinative method (usually 10 - 30 g). Grind the sample until it passes through a 10-mesh sieve.11.4Transfer the ground sample to an extraction vessel. The weight of a specificsample that a vessel will contain depends on the bulk density of the sample and the amount of drying agent (if any) that was added to the sample in order to make it suitable for extraction. Analysts should ensure that the sample aliquot extracted is large enough to provide the necessary sensitivity.11.5Prepare a method blank using an aliquot of a clean solid matrix such as quartz sand of the approximate weight of the samples. If a drying agent is added to the field samples being extracted, it must also be added to the method blank, in order to assess the possible contribution of the drying agent to the blank results.11.6Add the surrogates listed in the determinative method to each sample and method blank. Add the surrogates and the matrix spike compounds appropriate for the project to the two additional aliquots of the sample selected for spiking. If a drying agent is added to thefield samples being extracted, it must also be added to the matrix spike aliquots, in order to assess the effect of the drying agent.11.7Add approximately 25 mL of the appropriate solvent system to the vessel and seal the vessel as instructed by the manufacturer.11.8Place the extraction vessel into the instrument and proceed with apparatus setup as instructed by the instrument manufacturer. If recommended by the manufacturer, include additional vessels containing water or other materials to the apparatus in order to ensure that all samples are exposed to a consistent amount of microwave energy across extraction batches.11.9Recommended extraction conditionsTemperature:100-115E CPressure:50-150 psiTime at Temperature:10 - 20 minCooling:To room temperatureFiltering/Rinsing:With same solvent system11.9.1Optimize the conditions, as needed, according to the manufacturer'sinstructions. In general, the pressure is not a critical parameter, since it is a result of the solvent system vapor pressure at the elevated temperature.11.9.2Once established, the same procedure should be used for all samplesextracted for the same type of analysis.11.10Begin the extraction according to the instructions provided by the manufacturer.11.11Allow the extracts to cool to room temperature once the extractions are complete. After cooling, open the vessels and proceed with filtering and rinsing, combining all the filtrates.11.12The extract is now ready for concentration, cleanup, or analysis, depending on the extent of interferants and the determinative method to be employed. Refer to Method 3600 for guidance on selecting appropriate cleanup methods. Excess water present in extracts may be removed by filtering the extract through a bed of anhydrous sodium sulfate. Certain cleanup and/or determinative methods may require a solvent exchange prior to cleanup and/or analysis.12.0DATA ANALYSIS AND CALCULATIONSThere are no calculations explicitly associated with this extraction procedure. See the appropriate determinative method for the calculation of final sample results.13.0METHOD PERFORMANCE3546-8Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IVReference 4 presents a large body of information and specific data on a number of analytes. It provides the basis for a major portion of the performance work associated with this procedure. References 3 and 5 are reports of similar, more specific, studies. References 6 to 8 deal specifically with phenols. All of the method validation studies described in this method were performed using microwave apparatus operating at 2450 MHz.13.1Chlorinated pesticidesSingle-laboratory accuracy data were obtained for chlorinated pesticides extracted from soil, glass-fiber, and sand matrices. Concentrations of each target analyte ranged between 500 and 1,000 µg/kg. Four real-world split samples contaminated with pesticides and creosotes were also used (obtained from US EPA ERT, Edison, NJ). The latter were extracted by an independent laboratory using standard Soxhlet procedures and results compared to those obtained with this procedure. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by the appropriate determinative method. Method blanks and five spiked replicates were included. Work was also carried out to assess the level of degradation of thermally labile pesticides and it was found that no significant degradation takes place under the procedure described in this method. The data are reported in detail in Reference 4. Data summary tables are included in Method 8081.13.2Semivolatile organicsSingle-laboratory accuracy data were obtained for semivolatile organics extracted from soil, glass-fiber, and sand samples. Concentrations of each target analyte were about 500µg/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by the appropriate determinative method. Method blanks and five spike replicates were included. The data are reported in detail in Reference 4. Data summary tables are included in Method 8270.13.3PAHsSingle-laboratory accuracy data were obtained for PAHs extracted from five reference materials comprising marine sediments (HS-3, HS-4, and HS-5, all from the National Research Council of Canada), lake sediments (SRM-1491, from the National Institute of Science and Technology), and a soil contaminated with creosote (SRS103-100, from Fisher Scientific, Fairlawn, NJ). Work was also conducted with soil, glass-fiber, and sand samples spiked between 100 and 2,000 µg/kg. All samples were extracted using 1:1 hexane:acetone. One real-world split sample contaminated with creosote and pesticides was also used (obtained from US EPA ERT, Edison, NJ). The latter was extracted by one laboratory using standard Soxhlet procedures and results compared to those obtained with this procedure. Extracts were analyzed by the appropriate determinative method. Method blanks, spikes and five spiked replicates were included. The data are reported in detail in Reference 4. Data summary tables are included in Method 8270.13.4PCBsSingle-laboratory accuracy data were obtained for PCBs extracted from three reference materials (EC-1, EC-2, EC-3 - from Environment Canada). Work was also conducted with soil,3546-9Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IVglass-fiber, and sand samples spiked between 200 and 10,000 µg/kg (total PCBs). All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by the appropriate determinative method. Method blanks, spikes and spike duplicates were included for the low concentration spikes; matrix spikes were included for all other concentrations. The data are reported in detail in Reference 4. Data summary tables are included in Method 8082.13.5Chlorinated herbicides (phenoxyacid herbicides)Multi-laboratory accuracy data were obtained for chlorinated herbicides extracted from a certified spiked material (obtained from ERA, Arvada, CO). This soil was spiked by ERA at 100 µg/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by Method 8151. Method blanks and three replicates from five laboratories were included. Data summary tables are included in Method 8151.13.6PhenolsSingle-laboratory accuracy data were obtained for phenols extracted from a number of spiked soils and real-world split soils. Concentrations ranged between 200 and 10,000 µg/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by the appropriate determinative method. The data are reported in detail in References 4 to 8. Data summary tables are included in Method 8041.Multi-laboratory accuracy data were obtained for phenols extracted from a certified spiked material (obtained from ERA, Arvada, CO). This soil was spiked by ERA at 250 µg/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by Method 8041. Method blanks and three replicates from five laboratories were included. Data summary tables are included in Method 8041.13.7Organophosphorus pesticides and chlorinated herbicidesMulti-laboratory performance data were obtained for organophosphorus pesticides extracted from a certified spiked material (obtained from ERA, Arvada, CO). This soil was spiked by ERA at 250 µg/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by Method 8141. Method blanks and three replicates from five laboratories were included. Data summary tables are included in Method 8141.13.8Dioxins and furansSingle-laboratory accuracy data were obtained for dioxins and furans extracted from two soil reference materials (DX-1 from Environment Canada and SRM-1944 from NIST) containing the analytes of interest at concentrations between 10 and 6,000 ng/kg. All samples were extracted using 1:1 hexane:acetone. Extracts were analyzed by the appropriate determinative method. Method blanks, spikes and spike duplicates were included for the low concentration spikes; matrix spikes were included for all other concentrations. The data are reported in detail in References 9 and 10.14.0POLLUTION PREVENTION3546-10Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IVExtraction of organic compounds using microwave extraction conforms with EPA's pollution prevention goals. The volumes of solvent employed are generally smaller than with other extraction procedures.15.0WASTE MANAGEMENTLaboratory waste management procedures must be consistent with federal, state, and local regulations.16.0REFERENCES1K. Ganzler, A. Salgo and K. Valko. Microwave Extraction: A novel Sample Preparation Method for Chromatography. J. Chrom., 371, 299-306 (1986).2.J. R. J. Paré, J. M. R. Bélanger, and S. S. Stafford. Microwave-Assisted process(MAP TM): A new tool for the analytical laboratory. Tr. Anal. Chem. 13, 176-184 (1994). 3.V. Lopez-Avila, R. Young, and W. F. Beckert. Microwave-Assisted Extraction of OrganicCompounds from Standard Reference Soils and Sediments. Anal. Chem. 66, 1097-1106 (1994).4.K. Li, J. M. R. Bélanger, M. P. Llompart, R. D. Turpin, R. Singhvi, and J. R. J. Paré.Evaluation of rapid solid sample extraction using the microwave-assisted process(MAP TM) under closed-vessel conditions. Spectros. Int. J. 13 (1), 1-14 (1997).5.R. McMillin, L. C. Miner, and L. Hurst. Abbreviated microwave extraction of pesticidesand PCBs in soil. Spectros. Int. J. 13 (1), 41-50 (1997).6.M. P. Llompart, R. A. Lorenzo, R. Cela, and J. R. J.Paré. Optimization of a microwave-assisted extraction method for phenol and methylphenol isomers in soil samples using a central composite design. Analyst, 122, 133-137 (1997).7.M. P. Llompart, R. A. Lorenzo, R. Cela, J. R. J. Paré, J. M. R. Bélanger, and K. Li.Phenol and methylphenol isomers determination in soils by in-situ microwave-assisted extraction and derivatisation. J. Chromatogr. A 757, 153-164 (1997).8.M. P. Llompart, R. A. Lorenzo, R. Cela, K. Li, J. M. R. Bélanger, and J. R. J. Paré.Evaluation of supercritical fluid extraction, microwave-assisted extraction and sonication in the determination of some phenolic compounds from various soil matrices. J.Chromatogr. A, 774, 243-251 (1997).9. C. Chiu, G. Poole, Y. Shu, R. Thomas, and R. Turle. Microwave vs. Soxhlet for theextraction of dioxins and furans from solid samples. Organohalogen Compounds 27,333-338 (1996).3546-11Draft Revision 0September 1999 Pre-release version - This method has NOT been released by OSW as part of Update IV。
EPA方法索引
EPA方法索引根据您的要求，以下是EPA（美国环保局）使用的一些常见的方法索引。
这些方法涵盖了环境监测、风险评估、废物管理、空气质量评估和水质评估等各个领域。
请注意，这只是一个简要的索引，详细的方法描述和操作程序可以在EPA的官方网站上找到。
1.环境监测方法：-EPA方法1：样品获取和保留方法-EPA方法2：采样口和尾气采集系统评估方法-EPA方法3：抽样方法-EPA方法4：大气沉降物的抽样和分析方法-EPA方法5：大气礁石沉积物中颗粒物的采样和分析方法-EPA方法6：大气颗粒物的测定方法-EPA方法7：废气流中氮氧化物的测定方法-EPA方法8：高温、高湿废气流中苯/甲苯浓度的测定方法2.风险评估方法：-EPA方法9：风险评估基础指南-EPA方法10：风险评估的质量保证3.废物管理方法：-EPA方法11：可回收物品处理-EPA方法12：生物治理/垃圾填埋申请-EPA方法13：废物水处理系统操作4.空气质量评估方法：-EPA方法14：大气污染源排放计算-EPA方法15：大气质量模型基础指南-EPA方法16：大气氨浓度的测定方法-EPA方法17：大气细颗粒物的测定方法-EPA方法18：大气湿沉降物的收集和分析方法5.水质评估方法：-EPA方法19：水质评估基础指南-EPA方法20：废水处理工艺-EPA方法21：水样处理和分析方法-EPA方法22：饮用水质量监测这些方法索引只是EPA使用的一小部分方法。
EPA还有其他方法用于地下水监测、土壤污染评估、生物毒性评估和生态风险评估等。
为了确保准确性和合规性，使用这些方法时应仔细阅读相关的方法说明和操作程序，以确保正确的实施和数据采集。
用加速溶剂萃取(ASE)技术提取环境样品中的多环芳烃(PAHs)
分析结果
ASE萃取土壤以及海底沉积物中PAH的实验结果如表1和表2所示。由表1所示所有基质的加标回 收率与由索氏萃取8-18小时得到的基准值相符合。
在萃取池放入自动进样盘里，洗净的40ml收集瓶标上合适号码后（最多有20个）旋上配有隔垫的瓶 盖。
HPLC分析条件
根据HPLC分析的需要，ASE萃取液应稀释或者浓缩。HPLC系统使用的色谱柱为SUPELCOSIL 15-cm×4.6cm LC-PAH柱，流速为1.5ml/min。流动相为乙腈水溶液梯度淋洗：0-5min 60%水，40% 乙腈； 5-25min 乙腈从40%增加到100%（线性增加）。 同时用紫外和荧光检测器检测；紫外检测波 长254nm，荧光检测器激发波长300nm、发射波长410nm。采用外标法定量。
1.3
0.5
5.4
1.3
参考文献： 1. Richter, B.; Ezzell, J.; Felix, D. “Single Laboratory Method Validation Report: Extraction of TCL/PPL(Target Compound List/Priority Pollutant List) BNAs and Pesticides Using Accelerated Solvent Extraction(ASE) with Analytical Validation by GC/MS and GC/ECD”Document 116064.A, Dionex
环境分析中样品前处理新技术1
4、萃取条件的选择 萃取条件主要包括萃取溶剂的选择、萃取温度、萃取时 间等。 （1）萃取溶剂：微波加热的吸收体需要微波吸能物质，极 性物质是微波吸能物质，如乙醇、甲醇、丙酮或水等。因非 极性溶剂不吸收微波能，所以不能用100%的非极性溶剂作 微波萃取溶剂。 （2）萃取温度：由于制样杯置于密封罐中，内部压力可答 1MPa以上，因此，溶剂沸点比常压下的溶剂沸点提高许多。 如在密闭容器中丙酮的沸点可提高到164℃，丙酮-环己烷 （1：1）的共沸点提高到158 ℃，这样用微波萃取可以到达 常压下使用同样溶剂所达不到的萃取温度，既可提高萃取效 率又不致分解待测物。
目前ASE已被美国环保局（EPA）选定为推荐的标准方法 （方法编号：3545）
2、加速溶剂系统
ASE由HPLC泵、气路、不锈钢萃取池、萃取池加热炉、 萃取收集瓶等构成。
加速溶剂萃取工作流程图 所选择的HPLC泵是一种压力控制泵，萃取池采用316不锈钢制 造，用压缩的气体将萃取的样品吹入收集瓶内，萃取时有机溶剂的 选择与索氏萃取法相同。 萃取温度一般控制在150-200 ℃之间，压力通常为3.3-19.8MPa 左右,在上述条件下进行静态萃取,全过程约需15min左右
例1.微波萃取一高效液相色谱(HPLC)法测定土壤中16种多 环芳烃的研究（杨杰，干旱环境监测，2006，20（1）：5-7） 1、实验部分： 主要仪器HPLC，微波萃取仪(美国CEM公司)。氮吹浓 缩仪(美国LABCONCO公司)。 2、样品预处理： 1） 准确称取经冷冻干燥、研磨后过80目筛土壤样品l0 g，于聚四氟乙烯样品杯中，用30ml正己烷一丙酮(正己烷： 丙酮=1：1)溶剂浸泡10min后，在100 ℃微波萃取20 min。 2) 待微波萃取仪温度和压力下降后，将样品杯中的溶液 过无水硫酸钠层，用正己烷荡洗样品杯数次，并入过无水 硫酸钠层。
美国EPA3546新方法-微波快速溶剂萃取技术
美国EPA3546新方法-微波快速溶剂萃取技术
刘伟;张明祥
【期刊名称】《现代科学仪器》
【年(卷),期】2005(000)001
【摘要】由加拿大环保局和美国CEM共同开发的MARSX快速微波溶剂萃取技术,是世界上唯一专利的微波萃取技术,也是唯一符合美国EPA3546方法的仪器.低功率先行非脉冲微波技术实现连续高精确过程控制反应,通过高精度高频率的温压控制系统精确调节微波能量输出激发极性试剂,并且内置CARBOFLON加热和极化非极性试剂,实现了快速完全的样品萃取.
【总页数】4页(P52-55)
【作者】刘伟;张明祥
【作者单位】美国CEM公司,北京,100013;美国CEM公司,北京,100013
【正文语种】中文
【中图分类】O658.2
【相关文献】
1.快速溶剂萃取技术(ASE)在水环境监测中的比较研究及展望 [J], 计艺达
2.微波快速溶剂萃取新技术--MARSX(美国培安公司) [J],
3.抗生素提取过程中溶剂萃取技术新方法--超滤/萃取法 [J], 李十中;王淀佐;胡永平
4.快速溶剂萃取技术在农兽药残留检测中的应用与展望 [J], 张薇英;赵巧灵;戴意飞;
蒋玲波;唐雷鸣
5.应用加速溶剂萃取技术快速准确检测农药残留 [J], 韩会靖
因版权原因，仅展示原文概要，查看原文内容请购买。
微波萃取法
微波萃取法微波萃取法是一种高效、快速、环保的样品处理技术，可以用于提取各种物质中的有机成分。
本文将从微波萃取法的原理、优点、适用范围、操作步骤和注意事项等方面进行详细介绍。
一、微波萃取法的原理微波萃取法是利用微波能量对样品中所含有机物进行加热，使其在较短时间内达到沸腾状态，从而实现有机物与溶剂的快速有效分离。
由于微波能量具有穿透性和选择性，可以使样品内部均匀受热，同时不会对无机物产生影响，因此可以得到高效、准确的提取结果。
二、微波萃取法的优点1. 高效快速：相比传统提取方法，微波萃取法具有更高的提取效率和更短的提取时间。
2. 环保节能：使用微波萃取法可以减少溶剂用量和化学废弃物产生，从而达到环保节能的目的。
3. 准确可靠：由于微波能量具有穿透性和选择性，因此可以得到高度准确可靠的提取结果。
4. 操作简便：微波萃取法操作简便，只需将样品放入微波萃取仪中，设定相应的参数即可完成提取过程。
三、微波萃取法的适用范围微波萃取法适用于各种有机物的提取，特别是对于难以挥发的有机物和高沸点有机物具有很好的提取效果。
常见应用领域包括环境监测、食品安全、药物分析等。
四、微波萃取法的操作步骤1. 样品制备：将待测样品按照要求进行制备，如粉碎、研磨等。
2. 加入溶剂：将样品加入合适的溶剂中，使其达到合适的浓度。
3. 萃取条件设置：根据实际需要设置微波萃取仪的参数，如温度、时间等。
4. 开始提取：将样品装入微波萃取仪中，并启动设备开始提取过程。
5. 提取完成：当设定时间到达后，停止设备并将提取液收集起来即可进行后续分析处理。
五、注意事项1. 样品制备过程中要避免与空气接触，以免影响提取结果。
2. 萃取过程中要注意设备的安全使用，避免发生意外事故。
3. 操作时要严格按照设备说明书进行操作，避免出现误操作。
4. 提取完成后，要进行适当的溶剂回收和废弃物处理，达到环保节能的目的。
综上所述，微波萃取法是一种高效、快速、环保的样品处理技术，在各个领域都得到了广泛应用。
EPA3546-微波萃取
方法3546微波萃取 技术翻译；刘金云 mail:piery2006@ 1.0范围及应用1.1方法3546从是土壤﹑黏土﹑积沉物﹑废淤泥和固体弃物中提取可溶于水或微溶于水的有机化合物的程序.场购买剂统本方法是在市上可到的溶萃取系上发并展得到证实有效性的.本个样剂程序利用微波能源在一装有品和有机溶的闭产密的罐中生高温压条高件萃取，达到和索氏萃取(方法3540)相等的分析物回收率它，而使用的溶剂对较时间相少，所花的也比索氏萃取少。
证种应一旦分析者明某用方法具有合适的性能,它统它类分析者也可采用其的系或其型的容器.1.2挥发本方法适用于半性有机化合物,酯农药有机磷酸,氯农药有机,氯剂含除草,苯氧剂酸除草,酚类取代,氯联苯多(PCBs),PCDDs/PCDFs,这过种谱些均可通各的色方法分析.它标本方法也适用于其的目分析物的萃取,证标一旦分析者明在萃取此目分析物(参见方法3500册及本手第二章)时,够此程序具有足的性能.1.3对本方法于固体基体含有50-10，000μg/kg 挥发半性有机化合物，250-2，500μg/kg 酯农药的有机磷酸，10-5，000μg/kg 的氯农药氯剂有机和含除草,50-2，500μg/kg 酚类的取代，100-5，000μg/kg 苯氧剂的酸除草，1-5，000μg/kg 的PCBs 及10-6000ng/kg 的PCDDs/PCDFs 证实会这已有效。
本方法可能适用于含些分析浓样标浓围见物更高度的品，在目度范（方法3500内够证）的性能得到足的明之后，可采用本方法。
1.4仅细颗组样实话本方法适用于由微粒成的固体品。
如果可行的，在萃取之前，土壤/积样应气并研细风时沉物品放在空中干燥磨成微的粉末。
如果在干有工作安全及损问题分析物失，土壤/积样应与沉物品无钠处水硫酸混合或造成硅藻土粒作替代理。
预处总决测试灵理材料的重量取于方法的要求及分析所要求的敏度，一般地，需要的样为品2-20g 时来调节，同可以利用此萃取程序。
美国国家环保局EPA方法要点和推荐仪器
美国国家环保局EPA方法要点和推荐仪器EPA方法218.6离子色谱测定在饮用水、地下水和工业废水中的水溶性铬（1994年修订版3.3）应用范围测定饮用水、地下水和工业废水中的水溶性六价铬（如CrO2-4），这种方法的检测下限为0.4μg/L。
样品中如果含有大量的阴离子物质如硫酸或氯离子可能会引起色谱柱过载。
样品如果含有大量有机物或硫离子可能会引起可溶性的六价铬快速还原为三价铬。
样品贮存在4℃，在24小时内分析。
方法采用离子色谱法分析。
方法要点：水样经0.45μm滤膜过滤后，用浓缓冲溶液调节pH为9-9.5。
样品的测量体积为50-250μL进样到离子色谱。
保护柱去除样品中的有机物，六价铬以CrO2-4形式，在高容量的阴离子交换分离柱上分离，六价铬用双苯基苄巴脲柱后衍生，然后在530nm波长下检测有色络合物。
建议采用的仪器条件保护柱：Dionex IonPac NG1或与之相同的色谱柱分离柱：Dionex IonPac AS7或与之相同的色谱柱阴离子抑制器装置：Dionex Anion MicroMembrane Suppressor，其它抑制器必须有足够低的检测限和足够的基线稳定性。
色谱条件：色谱柱：保护柱-Dionex IonPac NG1, 分离柱-Dionex IonPac AS7淋洗液：250mM (NH4)2SO4, 100mM NH4OH, 流速=1.5 mL/min柱后试剂：2mM双苯基苄巴脲，10％ v/v甲醇，1N 硫酸，流速=0.5 mL/min 检测器：可见光530nm保留时间：3.8 分钟离子色谱测定无机阴离子(1993年八月，修订版2.2)应用范围1．可测定的阴离子包括A部分：溴离子，氯离子，氟离子，硝酸根，亚硝酸根，磷酸根，硫酸B部分：溴酸根，亚氯酸根，氯酸根2．基体包括：饮用水，地表水，民用水和工业废水，地下水，试剂用水，固体浸出液方法要点1．小量样品，一般2-3mL注入离子色谱，阴离子采用一个系统含有保护柱，分离柱，抑制器和电导检测器进行分离和检测。
微波萃取技术概述
微波萃取技术是一种用于从样品中提取化合物的分析方法，它利用微波辐射的能量来促使样品中的目标分子从固体或液体基质中被提取到溶剂中。
这种技术通常用于分析和检测食品、环境、药物、植物等样品中的化学成分。
以下是微波萃取技术的详细概述：1.原理：微波萃取利用微波辐射的能量在样品中产生快速的分子振动和摩擦，从而提高样品的温度和压力。
这种加热过程有助于分子在固体基质中的扩散和释放，从而促进目标分子从样品中转移到萃取溶剂中。
2.步骤：微波萃取通常包括以下步骤：–样品准备: 样品通常需要经过适当的预处理，如研磨、干燥等，以确保样品均匀性和可溶性。
–样品装入: 将预处理后的样品放入特制的微波反应容器中。
–添加溶剂: 向样品中添加适当的溶剂，该溶剂可与目标分子发生反应并提取出来。
–微波处理: 将样品置于微波设备中，通过微波辐射进行加热和萃取。
微波的频率和功率需根据样品性质进行调整。
–分离和分析: 萃取后，可以将萃取溶液用于进一步的分离和分析，如色谱、质谱等。
3.优势：–快速: 微波能够迅速提高样品温度，加速分子的扩散和转移，因此萃取速度较快。
–高效: 微波辐射能够促进目标分子从基质中释放，提高提取效率。
–少用溶剂: 由于高效的萃取，通常只需要少量溶剂。
–自动化: 微波萃取可以与自动化系统结合，提高样品处理的效率。
4.应用领域：微波萃取技术广泛应用于各个领域，包括食品分析、环境监测、药物分析、植物化学等。
它可以用于提取挥发性有机化合物、天然产物、药物成分、污染物等。
5.注意事项：–需要根据样品的性质和分析需求选择合适的微波参数和溶剂。
–微波辐射可能引发样品的化学反应或破坏，因此需要在选择微波参数时进行优化。
微波萃取技术是一种高效、快速的化学分析方法，适用于从各种样品中提取化合物。
它在实验室和工业中都有广泛的应用，有助于提高分析效率和准确性。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
美国EPA3546新方法---微波快速溶剂萃取技术刘伟张明祥杨海鹏（美国CEM公司，北京，100013）摘要：由加拿大环保局和美国CEM共同开发的MARSX快速微波溶剂萃取技术，是世界上唯一专利的微波萃取技术，也是唯一符合美国EPA3546方法的仪器。
MARSX获98年度全美R&D100大奖，低功率先行非脉冲微波磁控管技术实现连续高精确过程控制反应，MARSX利用闭环反馈控制技术，通过高精度高频率的温压控制系统精确调节微波能量输出激发极性试剂，并且内置CARBOFLON加热和极化非极性试剂，实现了快速完全的样品萃取制备，大大提高了现代气/液相色谱测定精度和效率。
其主要特点是: 快速, 安全，批量大，样品量大，节省溶剂，污染小。
前言样品预处理是样品分析过程中最关键、最耗时的环节。
在现代化实验室高度重视速度和效率的今天，探索快速、高效、简便、自动化的样品预处理新方法已成为当代分析化学的前沿课题和重要研究方向之一。
萃取是分离和提纯物质的一种常用方法，为GC、HPLC等有机分析方法提供样品前处理。
传统的萃取方法由于费时、费试剂、效率低、重现性差等缺点,已不能满足分析发展的需要,于是先后出现了微波辅助萃取（MAE）、超临界流体萃取(SFE)和加速溶剂萃取（ASE）等萃取方法。
但由于技术、成本和效率等问题，一些萃取方法在使用中受到了限制，而微波萃取则克服了以上的缺点, 表现出了巨大的应用潜力和良好的发展前景。
自从1986年匈牙利学者Ganzler提出了微波萃取法并从土壤、种子、食品、饲料中萃取分离化合物以来[1]，微波萃取技术以高效、低耗、无污染，成为近年来萃取技术的佼佼者,被誉为“绿色”萃取技术。
微波是指频率为300到300 000MHz的电磁波，介于红外线和无线电波之间。
民用微波频率一般采用2450MHz，所对应能量大约为0.96J/mol，微波的量子能级属于范德华力（分子间作用力）的范畴，与化合物键能相差甚远[2]。
USEPA通过对17种稠环芳香碳氢化合物、14种苯酚类化合物、8种碱性/中性化合物以及20种有机农药的研究认证了微波萃取法不会破坏任何被测分析物的分子结构。
微波在传输过程中依介质性质不同，会产生反射、吸收和穿透现象，这取决于材料本身的几个主要特性参数：介电常数、偶极矩、介电损耗因子和损耗tanδ等[3]。
在微波萃取中，被处理的物质通常是能够不同程度吸收微波能量的介质, 整个加热过程是利用离子传导和偶极子转动的机理，具有反应灵敏、升温速度快、效率高等优点。
微波萃取的机理可从两方面考虑：一方面是微波射线自由透过透明的萃取介质，深入到生物材料的内部维管束和腺胞系统。
由于吸收微波能，物料内部温度突然升高，在天然物料中的维管束和腺胞系统升温更快，保持此温度直至其内部压力超过细胞壁膨胀的能力，细胞破裂。
位于细胞内的有效成分从细胞壁自由流出，传递到萃取溶剂里。
另一方面，由于不同物质的tanδ值不同，对微波能的吸收程度也不同，微波可以对体系中不同组分进行选择性加热，从而使被萃取物质从基体或体系中分离出来, 进入到萃取溶剂中。
1．MARSX微波快速溶剂萃取和微波消解的技术差异微波消解技术是在酸条件下利用微波辐射能量作用于分子上，使之离子化，目的是破坏分子键。
而微波萃取则是利用微波辐射能量在溶剂的辅助下使分子从样品基体上分开，在剥离过程中不能破坏分子结构和分子键。
因此两者对微波能量发射要求是不同的，萃取时微波能量发射要尽可能微量低调，温度控制要十分准确。
微波萃取仪器根据萃取状态的不同一般分为密闭高压微波萃取和常压回流微波萃取两大类。
密闭微波萃取技术是由密闭容器中酸消解样品和液固萃取有机物两种技术组合演变而来的，与微波消解相比，其研究和应用还处于初始阶段[4]。
传统的微波发射方式，其边界条件不可测量不可定量，更有脉冲微波会产生瞬间高阈值电磁脉冲能量而可能破坏所萃取的有机分子形态的担心，所以实验重复性往往难以令人满意。
直到1998年，CEM公司开发出了新型ACCUPOWER连续低功率先行专利技术，并应用到微波萃取研究中，使得微波萃取实验达到更好的重复性和平行性。
MARSX的微波能量输出可控制性大大提高，消除了微波脉冲潜在的破坏性，从而可以完整保持待测萃取物分子形态。
低能量微波依然可促使分子产生高速偶极旋转，辅以高温和高压迅速克服基质与被分析物间的分子作用力，使被分析物从基质中解析出来并快速进入萃取溶剂。
由于被分析物瞬间溶出，避免了长时间高温导致的样品分解，有利于萃取热不稳定性物质，保持待测萃取物分子形态，特别适合于处理热敏性组分或从天然物质中提取有效成分。
2．微波快速溶剂萃取技术优势与其他萃取技术如索氏提取、自动索氏抽提、超声萃取、ASE、SFE和传统分液漏斗振摇等方法相比，微波快速溶剂萃取效率高，回收率高，安全性好，使用方便。
表1为10克样品利用微波快速溶剂萃取与其他的萃取方法的比较，从表中可以看出MAE和ASE在溶剂使用量上和萃取时间上都有很大的优势，但是MAE具备了ASE所没有的大批量、大样品量处理的能力，回收率上也可看出微波辅助萃取技术要优于其他技术。
因此微波萃取技术被美国环保局认定为标准方法EPA3546，应用于挥发性有机物和半挥发性有机物的萃取，与ASE快速溶剂萃取技术EPA3545标准方法并行采用。
同时微波萃取技术也符合ASTM D5765和ASTM D6010，分别用于密闭式微波萃取土壤及沉积物中的总石油碳氢化合物和密闭式微波萃取固体材料中的有机物。
微波快速溶剂萃取技术主要有以下优点：1）2）3）4）溶剂用量少。
10g样品仅需10～30mL溶剂，试剂量只为常规萃取的1/15左右。
微波萃取法回收率和重复性普遍优于其他萃取方法[5][6]。
微波萃取仪萃取容器每罐可达50-100mL容积，加入样品量可达10～50g，每批样品处理只需要5～20分钟即可达到非常好的萃取效果。
微波萃取法不受含水量的影响。
EPA用MARSX对不同含水量的土壤中农药的回收率进行了分析（见图1），认为微波萃取前可以无需样品干燥，这大大提高了分析的工作效率。
微波萃取免除了萃取前的样品干燥处理，因此样品含水量比其他的萃取技术对基体影响更小。
表1 萃取10克样品微波快速溶剂萃取与其他的萃取技术比较技术方法溶剂使用量萃取时间温压每次批处理量回收率索氏提取200～500mL 240min-48h沸点常压1个样中自动索氏提取50～100 mL 60-240 min沸点常压1个样中超声萃取150～200 mL 30-60 min 沸点常压1个样低ASE溶剂萃取 15～30 mL 12-30min 高温高压1个样较高MAE萃取 10～35 mL 5-20min 高温高压 14-40个样高图1 不同含水量对土壤中农药残留的回收率影响3．MARSX 萃取系统的技术特点EPA3546标准方法以MARSX 微波萃取仪为基础，并经过加州EPA 对MARSX 的评估，批准MARSX 作为唯一标准萃取仪器[7]。
密闭微波萃取仪由于其反应过程中可能产生高压，所以在仪器微波腔体和反应罐设计上必须有特殊考虑。
MARSX 是CEM 公司新一代的密闭高压微波萃取仪，拥有许多先进技术和专利，更由于其低功率先行技术获得了98年度全美R&D100大奖。
1）2）3） CEM 专利的ACCUPOWER 技术。
ACCUPOWER 无须功率设定，反应过程中功率可以随反应自动调整输出。
MARSX 低功率优先连续微波输出，根据密闭罐中反应条件的变化实时精确控制和调整微波发射功率，保持了待测萃取物分子形态的完整性，相比其他简单的设定固定功率输出的脉冲微波技术产品有根本性的技术进步。
CARBOFLON 强极性激活技术。
通过内置极化CARBOFLON 加热和极化非极性试剂，使非极性试剂也能在微波场下迅速加热，从而使微波快速溶剂萃取技术可广泛适用于包括极性和非极性的各种试剂。
图2为在微波作用下非极性正己烷溶剂在加入Carboflon 后，其升温效果达到了极性丙酮溶剂的效果，扩大了微波萃取中非极性溶剂的使用范围。
RTP 光纤温度传感系统。
由于热电偶传感器在微波电磁场中会产生打火花现象，极易引起有机试剂爆炸，且由于其检测精度和响应时间慢等原因，一般不用于精确过程控制。
RTP 温度控制系统采用高频率和高精确的光纤温度传感器，采用高纯度熔融二氧化硅直接制成，无电磁干扰，避免了微波腔内的爆炸危险性。
高频光纤RTP 传感器，可随时观察到反应罐内的温度数值并反馈给ACCUPOWER 系统，精确监控萃取变化过程。
图2 加入Carboflon升温效果对比4）5）6）7）8）1）底部IR全罐测温系统。
CEM独有的底部IR技术可同时监测所有反应罐中的温度，并随时与RTP进行相互温度标定，保证系统的精度和可靠性。
大批量和大样品量的处理能力。
MARSX微波快速溶剂萃取批处理达到14-40个样，进行固体半固体萃取的效率远远高于任何其他的萃取技术。
高速磁搅拌系统。
由于电磁搅拌的作用，增进了萃取容器中气、液、固之间的充分接触，减少试剂使用以及污染，大大缩短萃取时间，提高萃取回收率。
高灵敏度有机试剂检测系统。
微波萃取一般在高压密闭容器中进行，如果实验条件控制不好，造成萃取试剂泄漏后在微波场中很容易造成危险。
CEM设计了一套高灵敏有机试剂检测系统，一旦检测值达到丙酮混爆值下限的20%时即发出警告并自动停止微波发射，避免了潜在危险。
MARSX反应容器密闭保证萃取过程中不泄漏挥发性物质和有机溶剂，宇航纤维复合材料的耐压外套和垂直定向防爆设计保证安全性。
4．微波快速萃取在农业和食品的应用微波快速溶剂萃取技术已经广泛应用于农产品、食品、环境土壤监测、烟草、化妆品、造纸、中医药材、石化等等领域。
例如监测土壤、淤泥等中有毒有害物质的污染情况[8][9]、萃取PVC中增塑剂等[10]。
农业领域微波快速溶剂萃取种子中的油；萃取谷物、蔬菜、水果、茶叶、鱼肉和其他动物组织中农药残留如：有机氯、有机磷杀虫剂、除草剂、多氯联苯、多环芳烃和二噁英等；萃取动物饲料中的农残；萃取动物肝脏和组织中兽药代谢及残留。
CEM在2000年度Pittsburgh会议上报告了从鱼肉组织中萃取4,4-DDT，2,4-DDT，4,4-DDD，4,4-DDE，Nonachlor，a-Chlordane 农药残留[11]，图3所示的实验回收率表明MAE法的回收率可与传统soxhlet法相媲美，而且大部分分析结果均优于soxhlet法。
图3微波法与索氏法萃取鱼肉组织中农药含量对比图（ng/g）罗建波等人利用微波萃取和气相色谱法测定果蔬中农药残留，研究结果表明微波萃取法试剂消耗小，样品量小，回收率高，指出MAE对有机物的萃取具有广阔的应用前景[12]。