Quotation About the 10ml & 3ml Spray Bottles From Belle_Yu

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四川省成都市华川中学2021年高二英语上学期期末试题含解析

四川省成都市华川中学2021年高二英语上学期期末试题含解析一、选择题1. —That's the third time he's won the award in this field．—Yes. He ______ his maximum potential in the past decade．A. exploredB. is exploringC. has been exploringD. had explored参考答案：C2. Hearing their grandpa was coming, they began to ________ the work to prepare for a nice dinner.A．set off B．set down C．set aside D．set about参考答案：C略3. Chinese people have traditionally cherished the virtue(美德) of eating bitter, or the abilityto_______ hardships without complaint.A．put up with B．end up with C．come up with D．catch up with参考答案：A4. -----They are quiet, aren’ t they?-----No. They are accustomed_____at meals.A. to talkB. to not talkC. to talkingD. to not talking参考答案：C5. Once we lose the farm, the _________ of poverty(贫困) will be sure.A. statementB. admissionC.approach D. occupation 参考答案：C略6. Last year the advertising rate __________ by 20 percent.A. raisedB. raisingC. was risingD. rose参考答案：D7. Like some of my classmates, I cannot live up to my teacher's expectations; ________ I let them down. A．in other words B．after allC．what's more D．more or less参考答案：D句意：像我的一些同学一样，我辜负了老师们的期望，我或多或少让他们失望了。

英文药品说明书关于用量与用法的写法

英文药品说明书关于用量与用法的写法下面是店铺整理的英文药品说明书关于用量与用法的写法，欢迎大家阅读!本项最常用的英语表示法有：Dosage and Administration 用(剂)量与用法Route of Administration 给药途径(用法)Administration 用法Direction for Use 用法Method of (for) Administration 用法Application and Dosage 用法与用(剂)量Mode of Application 用法Dosage 用(剂)量How to Use 用法Posology 剂量学还可能有其他的表示方法。

本项也是阅读的重点，读者必须正确理解本项内容中的给药对象、给药方式、剂量及剂量单位、给药时间等。

1、每次给药次数的表示方法daily (per day, a day, every day ) 每日every …hours 每隔…小时intervats of … 每隔…once (twice) daily (a day) 每日一(二)次every other day 每隔一日three times a day (daily) 每日三次three times a week 每周三次once (twice) a week (weekly) 每周一(二)次Divided into … doses 分…次in two or three divided doses 分为二或三次(个剂量)例1 Unless other wise prescribed by the physician, theaverage daily dose is 1 capsule 3 times daily.如果医生不另开处方，平均日剂量为每日3次、每次1个胶襄。

例2 The suggested dose is 10 to 15 mg per kg dody weight daily in 3-4 divided doses orally, taken with meets.日剂量最好每公斤体重10-15mg，分3-4次口服，与食物共服。

USP《671》美国药典包装容器——性能检测译文

《671》包装容器——性能检测本章规定了用来包装的塑料容器及其组件功能性质上的标准(药品、生物制剂、营养补充剂和医疗器械)，定义了保存、包装、存储和标签方面的凡例与要求。

本文提供的试验用于确定塑料容器的透湿性和透光率。

盛装胶囊和片剂的多单元容器章节适用于多单元容器。

盛装胶囊和片剂的单位剂量容器章节适用于单位剂量容器。

盛装胶囊和片剂的多单元容器(没有密封) 的章节适用于没有密封的聚乙烯和聚丙烯容器。

盛装液体的多元和单元容器的章节适用于多元的和单元的容器。

一个容器想要提供避光保护或作为一个符合耐光要求的容器，由具有耐光的特殊性质的材料组成，包括任何涂层应用。

一个无色透明或半透明的容器通过一个不透明的外壳包装变成耐光的(见凡例和要求 )，可免于对光的透射要求。

在多单元容器和封盖与水泡的单位剂量容器由衬垫密封情况下，此处使用的术语“容器”指的是整个系统的组成。

盛装胶囊和片剂的多元容器干燥剂——放置一些颗粒4—8目的无水氯化钙在一个浅的容器里，仔细剔除细粉，然后置于110°干燥，并放在干燥器中冷却。

试验过程——挑选12个类型和尺寸一致的容器，用不起毛的毛巾清洁密闭表面，并打开和关闭每个容器30次。

坚决每次应用容器密闭一致。

通过扭矩关闭螺旋盖容器，使气密性在附表规定的范围内。

10个指定的测试容器添加干燥剂，如果容器容积大于等于20mL，每个填充13mm以内封闭；如果容器的容积小于20毫升，每个填充容器容量的三分之二。

如果容器内部的深度超过63mm，惰性填料或垫片可以放置在底部来最小化容器和干燥剂的总重量；干燥剂层在这样一个容器中深度不低于5cm。

添加干燥剂之后，立即按附表中规定的扭矩封闭螺旋帽容器。

剩余的2个指定为对照容器，每个添加足够数量的玻璃珠，重量约等于每个测试容器的重量，并用附表中规定的扭矩封闭螺旋帽容器。

记录各个容器的重量，如果容器的容积小于20毫升，精确到0.1毫克；如果容器容积为20毫升或以上但小于200毫升，精确到毫克；如果容器容积为200毫升及以上，精确到厘克（10毫克）；在相对湿度75±3%和温度23±2°的环境下存储。

商务翻译(汉译英) Unit 4 “××”牌羊绒衫 (广告)

一般而言, 商标词与商品属性之间表现为三种关系: 零关系、直接关系和间接关系。英语商标词与商品属性的关系基本上为以上三种关系, 但以零关系居多, 如 Rejoice 是美国洗涤品的名称,意为“高兴”; 汉语商标词与商品属性之间多为间接关系, 如: “立白” (洗涤品) 使人联想到“立即变得白白净净”之义, 从而激发人们的购买欲望。
(英语商标词常使用杜撰的词汇, 注意语音的表现。著名商标词 Kodak 就是一例。该公司创始人George Eastman 曾说, “K一直是我偏好的字母, 他看上去有力而充满活力, 因此, 我想采用的商标必须以K 开头, 然后找几个字母与之匹配,最后以K结尾。”Kodak 就是这种考虑的结果。汉语商标词却总是充分利用现有词汇, 并注重语义的表达。如: “健力宝” (饮料) 蕴涵健康、有活力之义,“春兰” (空调) 使人联想到宜人的春天, 清风拂面, 令人凉爽。
英汉商标词的差别
作为商标词, 英汉商标词都具有简短、易读、易记以及引起消费者兴趣和好感的共性, 然而, 由于英汉两种语言和文化的不同, 英汉商标词也表现出诸多差异。具体表现如下:(1) 英语商标词倾向于使用人名, 尤其是公司创始人或产品的发明者名称, 较少使用地名, 如:Ford (汽车) 来自于公司创始人Henry Ford 之名,Goodyear (轮胎) 是为纪念硫化橡胶发明人Charles Goodyear 而为一种轮胎起的名字; 而汉语商标词多选用动植物名称或地名, 如: “凤凰”自行车、“熊猫”电视、“椰树”饮料、“青岛”啤酒、“北京”吉普车等。
Safeguard : 舒肤佳 Safeguard 意为“保安”, 如若意译, 很难在中
国消费者心中留下深刻的印象。“舒肤佳”这一译名在读音、音节方面都与原语相近(按粤语发音) ,并且 “肤”字表示该商品的用途, “舒”给人以滑爽舒服的感觉, 而“佳”则表明它的功能效果,“舒肤佳”向顾客传递了“用了之后皮肤会感到舒服”的信息, 此译名谐音切义, 易引发消费者尝试欲购的消费心理, 堪称妙译。

反应总结参考文献22

Chiara Brullo,† Matteo Massa,† Massimo Rocca,† Chiara Rotolo,† Sara Guariento,† Daniela Rivera,‡ Roberta Ricciarelli,‡ Ernesto Fedele,§ Paola Fossa,† and Olga Bruno*,†
© XXXX American Chemical Society
■
domain, a phenylalanine residue, replaced by a tyrosine in PDE4A, B, and C, has been proposed by Gurney and coworkers as a key interaction site for allosteric inhibitors.6 More recently, an additional C terminal helix (named conserved region 3, CR3) has been identiﬁed by the same authors in a protein construct used to cocrystallize the catalytic domains of PDE4 with diﬀerent small molecules active as inhibitors.7 As diﬀerent sequences have been evidenced in CR3 domain of PDE4D and PDE4B, the speciﬁc interaction with catalytic pocket and CR3 terminal domain has been suggested as a possible key point for selective inhibitors development. However, this additional information is still diﬃcult to be used for the rational design of new compounds, due to the ﬂexibility shown by UCR2 and CR3 domains. In fact, they are the most external parts of the protein, and in the absence of the complete 3D structure of the enzyme, which could assign them a speciﬁc region to be occupied, they are free to move in a consistent way during in silico simulation. In the last 15 years, several strategies designed to enhance cerebral cAMP by PDEs inhibition have been proposed for the

美国药典USP31无菌检查

美国药典USP31-NF26无菌检查法《71》.doc71 STERILITY TESTS 无菌检查法Portions of this general chapter have been harmonized with the corresponding texts of the European Pharmacopeia and/or the Japanese Pharmacopeia. Those portions that are not harmonized are marked with symbols () to specify this fact.此通则的各部分已经与欧洲药典和/或日本药典的对应部分做了协调。

不一致的部分用符号（）来标明。

The following procedures are applicable for determining whether a Pharmacopeial article purporting to be sterile complies with the requirements set forth in the individual monograph with respect to the test for sterility. Pharmacopeial articles are to be tested by the Membrane Filtration method under Test for Sterility of the Product to be Examined where the nature of the product permits. If the membrane filtration technique is unsuitable, use the Direct Inoculation of the Culture Medium method under Test for Sterility of the Product to be Examined. All devices, with the exception of Devices with Pathways Labeled Sterile, are tested using the Direct Inoculation of the Culture Medium method. Provisions for retesting are included under Observation and Interpretation of Results.下面这些步骤适用于测定是否某个用于无菌用途的药品是否符合其具体的各论中关于无菌检查的要求。

Kessler心理困扰量表（K10）说明书

Kessler Psychological Distress Scale (K10)Source: Kessler R. Professor of Health Care Policy, Harvard Medical School, Boston, USA.This is a 10-item questionnaire intended to yield a global measure of distress based on questions about anxiety and depressive symptoms that a person has experienced in the most recent 4 week period.Why use the K10The use of a consumer self-report measure is a desirable method of assessment because it is a genuine attempt on the part of the clinician to collect information on the patient’s current condition and to establish a productive dialogue. When completing the K10 the consumer should be provided with privacy.(Information sourced from the NSW Mental health Outcomes and Assessment Training (MH-OAT) facilitator’s Manual, NSW Health Department 2001)How to administer the questionnaireAs a general rule, patients who rate most commonly “Some of the time” or “All of the time” categories are in need of a more detailed assessment. Referral information should be provided to these individuals. Patients who rate most commonly “A little of the time” or “None of the time” may also benefit from early intervention and promotional information to assist raising awareness of the conditions of depression and anxiety as well as strategies to prevent future mental health issues.(Information sourced from the NSW Mental health Outcomes and Assessment Training (MH-OAT) facilitator’s Manual, NSW Health Department 2001)K10 TestThese questions concern how you have been feeling over the past 30 days. Tick a box below each question that best represents how you have been .1. During the last 30 days, about how often did you feel tired out for no good reason?1. None of the time2. A little of thetime3. Some of thetime 4. Most of the time5. All of thetime10. During the last 30 days, about how often did you feel worthless?1. None of the time2. A little of thetime3. Some of thetime 4. Most of the time5. All of thetimeScoringFOR DOCTOR'S EYES ONLYThis is a questionnaire for patients to complete. It is a measure of psychological distress. The numbers attached to the patients 10 responses are added up and the total score is the score on the Kessler Psychological Distress Scale (K10). Scores will range from 10 to 50. People seen in primary care who* score under 20 are likely to be well* score 20-24 are likely to have a mild mental disorder* score 25-29 are likely to have moderate mental disorder* score 30 and over are likely to have a severe mental disorder13% of the adult population will score 20 and over and about 1 in 4 patients seen in primary care will score 20 and over. This is a screening instrument and practitioners should make a clinical judgement as to whether a person needs treatment. Scores usually decline with effective treatment. Patients whose scores remain above 24 after treatment should be reviewed and specialist referral considered.References:Kessler, R.C., Andrews, G., Colpe, .et al (2002) Short screening scales to monitor population prevalences and trends in non-specific psychological distress. Psychological Medicine, 32, 959-956.Andrews, G., Slade, T (2001). Interpreting scores on the Kessler Psychological Distress Scale (k10). Australian and New Zealand Journal of Public Health, 25, 494-497.。

10%硫代硫酸钠的水溶液英语

10%硫代硫酸钠的水溶液英语10% Sodium Thiosulfate Aqueous SolutionSodium thiosulfate is an important chemical compound widely used in various industries and applications. In this document, we will specifically focus on the properties, preparation, and applications of a 10% sodium thiosulfate aqueous solution.1. IntroductionSodium thiosulfate (Na2S2O3) is a crystalline compound that is highly soluble in water. It is commonly used in the fields of photography, medicine, analytical chemistry, and environmental protection. The 10% sodium thiosulfate aqueous solution refers to a solution where 10 grams of sodium thiosulfate is dissolved in 100 milliliters of water.2. PropertiesThe 10% sodium thiosulfate aqueous solution is transparent and colorless. It has a slight sulfur odor. The pH of the solution is neutral, which means it is neither acidic nor alkaline. This solution is stable under normal conditions and does not decompose easily.3. PreparationTo prepare a 10% sodium thiosulfate aqueous solution, the following steps can be followed:Step 1: Measure 10 grams of sodium thiosulfate using an analytical balance.Step 2: Add the measured sodium thiosulfate into a beaker or a flask.Step 3: Carefully add 100 milliliters of distilled water to the beaker.Step 4: Stir the mixture gently until all the sodium thiosulfate is dissolved.Step 5: Transfer the solution to a clean and tightly-sealed container for storage or further use.4. ApplicationsThe 10% sodium thiosulfate aqueous solution has various practical applications, including:4.1 Photography: Sodium thiosulfate is commonly used as a fixer in the development of photographic films and papers. It helps in removing the undeveloped silver halide crystals from the emulsion, making the image stable and permanent.4.2 Medical Uses: Sodium thiosulfate can be used in medical treatments, such as in the management of cyanide poisoning. It acts as an antidote by combining with cyanide to form a non-toxic thiocyanate compound.4.3 Analytical Chemistry: Sodium thiosulfate solution is used as a titrant for the determination of iodine concentration in solutions. It is also employed as a reducing agent in various chemical reactions.4.4 Water Treatment: Sodium thiosulfate is utilized in water treatment processes to neutralize chlorine levels in swimming pools and spas. It helps to remove the strong smell of chlorine and lessen its harmful effects on the skin and eyes.ConclusionIn conclusion, the 10% sodium thiosulfate aqueoussolution plays a significant role in various industries and applications. Its properties, preparation method, and diverse applications have been explored in this document. From photography to medical treatments and water treatmentprocesses, sodium thiosulfate proves to be a versatile and valuable compound.。

美国FDA关于注射剂和生物制品允许的体积过量及标示量指导原则(2015-6-24终稿)

Labeled Vial Fill Size in Injectable Drug and BiologicalProductsGuidance for IndustryU.S. Department of Health and Human ServicesFood and Drug AdministrationCenter for Drug Evaluation and Research (CDER)Center for Biologics Evaluation and Research (CBER)June 2015Pharmaceutical Quality/CMCLabeled Vial Fill Size in Injectable Drug and BiologicalProductsGuidance for IndustryAdditional copies are available from:Office of Communications, Division of Drug InformationCenter for Drug Evaluation and ResearchFood and Drug Administration10001 New Hampshire Ave., Hillandale Bldg., 4th FloorSilver Spring, MD 20993Phone: 855-543-3784 or 301-796-3400; Fax: 301-431-6353druginfo@/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htmand/orOffice of Communication, Outreach and DevelopmentCenter for Biologics Evaluation and ResearchFood and Drug Administration10903 New Hampshire Ave., Bldg. 71, Room 3128Silver Spring, MD 20993Phone: 800-835-4709 or 240-402-7800Email: ocod@/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/default.htmU.S. Department of Health and Human ServicesFood and Drug AdministrationCenter for Drug Evaluation and Research (CDER)Center for Biologics Evaluation and Research (CBER)June 2015Pharmaceutical Quality/CMCTABLE OF CONTENTSI.INTRODUCTION (1)II.BACKGROUND (2)III.OVERVIEW (2)A.Allowable Excess Volume (2)beled Vial Fill Size (3)IV.DISCUSSION AND RECOMMENDATIONS (3)Allowable Excess Volume and Labeled Vial1 Fill Size in Injectable 1Drug and Biological Products2Guidance for Industry23456This guidance represents the current thinking of the Food and Drug Administration (FDA or Agency) on 7this topic. It does not establish any rights for any person and is not binding on FDA or the public. You 8can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations. 9To discuss an alternative approach, contact the FDA staff responsible for this guidance as listed on the 10title page.11121314I. INTRODUCTION151617This guidance provides the pharmaceutical industry with the Center for Drug Evaluation and18Research’s (CDER’s) and the Center for Biologics Evaluation and Research’s (CBER’s) current 19thinking on allowable excess volume and labeled vial fill size in injectable drug and biological 20products. It replaces the draft of the same name that was published on March 14, 2014 (79 FR 2114517). Specifically, the guidance clarifies the FDA regulatory requirements and22recommendations pertaining to allowable excess volume in injectable vials and describes when 23justification is needed for a proposed excess volume in these injectable drug3 products. This24guidance also discusses the importance of appropriate fill volumes for injectable drug products 25and recommends that labeled vial fill sizes be appropriate for the intended use and dosing of the 26drug product.27This guidance addresses withdrawable volume and labeled vial fill size for injectable drug2829products that are packaged in vials and ampules, including products that require reconstitution.30It does not address injectable drug products in other packaging types (e.g., prefilled syringepackage systems and intravenous infusion bags) or noninjectable products, because there may be3132unique considerations for these packaging configurations. The recommendations in this33guidance apply to new drug applications (NDAs), abbreviated new drug applications (ANDAs), 34biologics license applications (BLAs), as well as supplements or other changes to these35applications for new packaging or other changes that may affect the fill volume.3637In general, FDA’s guidance documents do not establish legally enforceable responsibilities.38Instead, guidances describe the Agency’s current thinking on a topic and should be viewed only 39as recommendations, unless specific regulatory or statutory requirements are cited. The use of1 The term vial used throughout this guidance refers to both vial and ampule package types.2 This guidance has been prepared by the Office of Pharmaceutical Quality in the Center for Drug Evaluation andResearch in collaboration with the Center for Biologics Evaluation and Research at the Food and DrugAdministration.3 The term drug used throughout this guidance refers to drugs, including biological drug products.40the word should in Agency guidances means that something is suggested or recommended, but 41not required.4243II. BACKGROUND4445Injectable vial misuse, including unsafe handling and injection techniques, has led to vial46contamination and an increased risk of bloodborne illness transmission between patients.4,547Inappropriate excess volume and labeled vial fill sizes are two factors that may contribute to48unsafe handling and injection practices by consumers and health care providers. FDA has been 49concerned about these issues and is publishing this guidance to clarify its regulatory50requirements and recommendations.51III. OVERVIEW525354A. Allowable Excess Volume5556The United States Pharmacopeia (USP) General Chapter <1> Injections provides that each57container of an injectable product is filled with a volume that slightly exceeds the contentindicated in the labeling.6 The excess volumes are meant to be sufficient to permit withdrawal5859and administration of the labeled volumes. FDA regulations at 21 CFR 201.51(g) provide that 60for drugs in ampules or vials that are intended for injection, the declaration of net quantity of61contents on the label is considered to express the minimum quantity of contents and further62requires that variation above the stated measure must comply with the excess volumes set forth 63in USP. USP General Chapter <1151> Pharmaceutical Dosage Forms provides excess volume 64recommendations for mobile and viscous liquids in a range of fill volumes, noting that the excess 65volumes recommended are usually sufficient to permit withdrawal and administration of the66labeled volumes. Allowable excess volume may also be referred to as “overfill,” but should not 67be confused with “overage,” which is addressed in a separate guidance.7 Generally, an applicant 68should not declare the amount of overfill on the container label.694 Perz J, Thompson N, Schaefer M, Patel P, 2010, US Outbreak Investigations Highlight the Need for Safe InjectionPractices and Basic Infection Control, Clinics in Liver Disease, 14:137-151.5 Centers for Disease Control and Prevention, Injection Safety, Safe Injection Practices to Prevent Transmission ofInfections to Patients, 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (/injectionsafety/IP07_standardPrecaution.html).6 For a drug product for which there is an official USP drug product monograph, the product must comply with thestandards set forth therein, including the standards set forth in General Chapter <1>, unless expressly excepted in that drug product monograph. See Federal Food, Drug, and Cosmetic Act, sections 501(b) (21 U.S.C. 351(b)) and 502(g) (21 U.S.C. 352(g)); USP 37-NF 32, General Notices and Requirements 2.10. Official Text. Thus, for aninjectable drug product for which a USP monograph exists and incorporates General Chapter <1>, the provision regarding inclusion of a slight volume exceeding the labeled volume is a mandatory requirement; for injectableproducts without a USP monograph that incorporates General Chapter <1>, compliance with the slight excessvolume provision is strongly recommended. USP has proposed moving the text discussing the container content from USP General Chapter <1> Injections to USP General Chapter <697> Container Content for Injections. These proposed changes are being considered for USP 38.7Overage is an amount of a drug substance in excess of the label claim. The use of an overage to compensate for degradation during manufacture or a product’s shelf life, or to extend the shelf life is generally discouraged. The use of an overage is discussed in section 2.2.2 of the International Conference on Harmonisation (ICH), Guidance for Industry, Q8(R2) Pharmaceutical Development.FDA becomes concerned when the excess volume in a vial is greater or less than the USP7071recommended amount without appropriate justification. Such excesses and deficiencies may72result in medication errors and may lead to misuse of leftover drug product or pooling of vials to obtain a single dose.737475beled Vial Fill Size7677While dosing flexibility is necessary with injectable drug products, applicants should determine 78the appropriate vial fill sizes during product development, considering how the vials are likely to be used. For example, single-dose vials are designed for use in a single patient as a single7980injection/infusion. However, even when appropriately labeled, single-dose vials that contain81significantly8 more drug than is required for a single dose may result in the misuse of the leftover 82drug product. Similarly, the need to combine several single-dose vials for a single patient dose 83may lead to medication errors and microbial contamination.8485According to USP General Chapter <1>, multiple-dose vials have a maximum container volume 86sufficient to permit the withdrawal of not more than a total of 30 mL, unless otherwise specified in the USP drug product monograph.9,10 Setting a maximum volume in multiple-dose vials will 87minimize vial septum punctures, which will reduce the risk of compromising vial integrity and8889the potential for vial contamination.90IV. DISCUSSION AND RECOMMENDATIONS919293With respect to allowable excess volume, the applicant of drugs in ampules or vials intended for 94injection must follow the requirements in 21 CFR 201.51(g). The regulation requires an95applicant to comply with the excess volume recommendations prescribed by the USP.96Therefore, for drugs in ampules and vials intended for injection, the applicant must comply with 97the excess volume recommendations that appear in USP General Chapter <1151>.11 In the case 98of drug products requiring reconstitution, the product should be designed to meet the label claim 99and acceptable overfill, and allow for correct dosing. Deviations from the recommendations in 100USP General Chapter <1151> with regard to excess volume should be justified.12 FDA101recommends providing the justification by obtaining extractable content testing data, which is8 While it is not possible to specify a quantitative volume of remaining drug product that would generally beconsidered significant, volumes remaining that could provide a second dose, or would encourage pooling for asecond dose, would be considered excessive.9 USP has proposed moving the text discussing the maximum container volume for multiple-dose vials from USPGeneral Chapter <1> Injections to USP General Chapter <659> Packaging and Storage Requirements. Theseproposed changes are being considered for USP 38.10 For products without a USP monograph, multiple-dose vials must have a maximum fill volume sufficient topermit the withdrawal of not more than 30 mL, unless justified in the application.11 Typically, USP General Chapters titled with numbers above <1000> are considered to be recommendations andnot requirements, unless the chapter is cited in a product-specific monograph or another General Chapter titled witha number below <1000>. However, in this case, because FDA’s regulations specifically require adherence to theUSP recommendations on this topic, the recommendations in USP General Chapter <1151> are considered to berequirements.12 For example, for a drug product requiring reconstitution that is dosed based on body weight, it is important for thefinal concentration to be a whole number that allows for easy calculation and withdrawal of the appropriate dose.This consideration may be used to justify a slight deviation from the recommended overfill.102described in USP General Chapter <1> under Packaging, Determination of Volume of Injection 103in Containers, or other appropriately justified methods. A variety of approaches may be104considered acceptable for sample collection, for example:105106•For BLAs: Lot release testing and/or collection from batches representative of the commercial process, using appropriate sampling and methods.107108109•For NDAs and ANDAs: One or more batches representative of the commercial 110process as part of the product development studies using appropriate sampling 111and methods.112113The applicant should provide data related to proposed excess volume in the following sections of 114the application:13115116•The excess volume included in a drug product should be described in the common 117technical document (CTD) section 3.2.P.1, Description and Composition of the 118Drug Product.119120•The studies and justification (i.e., extractable volume testing, viscosity studies, fill 121volume variability) should be described in CTD section 3.2.P.2.2.1, Formulation 122Development and/or 3.2.P.2.3, Manufacturing Process Development.123124FDA recommends that a drug product’s vial fill size should be appropriate for the labeled use 125and dosing of the product.14 FDA may request justification when there are questions about the 126appropriateness of the proposed labeled vial fill sizes in an application. When deciding what is 127appropriate, applicants should consider the following:128129•Single-dose vials should not contain a significant15 volume beyond what would be 130considered a usual or maximum dose for the expected use of the drug product. 131132•Consumers and/or health care providers should not be routinely required to use 133more than one vial to administer a typical single dose of the drug product.134135•Multiple-dose vials should contain no more than 30 mL of drug product except under specific circumstances.16136137138For all application types, the applicant should communicate with FDA early in the drug139development process about the vial fill size and unique excess volume concerns. For example,13 Guidance for Industry, M4: The CTD – Quality Questions and Answers/Location Issues/downloads/drugs/guidancecomplianceregulatoryinformation/guidances/ucm073285.pdf.14 An ANDA that references a currently approved reference listed drug (RLD) is generally expected to have thesame labeled vial fill size as the RLD. In the event of a suitability petition permitting a change in vial fill size, the basic principles of this guidance would be applied to the petitioned ANDA.15 See footnote 8 for information on significant volumes.16 Exceeding the 30mL multiple-dose vial limit may be justified if the usual dose of the drug product packaged in amultiple-dose vial is large, making the 30 mL limit impractical.140applicants should consider such communications during the end of phase II meetings or other 141communications for investigational new drug applications (INDs).142143We recommend communicating with FDA as outlined in existing recommendations related to 144communication with applicants, including the Guidance for Review Staff and Industry Good 145Review Management Principles and Practices for PDUFA Products.1717 See/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM079748.pdf.We update guidances periodically. To make sure you have the most recent version of a guidance, check the FDA Drugs guidance Web page at/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm and the CBER Web page./BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/default.htm.。

RAE Systems VOC (Total Organic Vapor) Test Equipme

TN-102 TECHNICAL NOTE_______________________________________________________________1339 Moffett Park Drive, Sunnyvale CA 94089 U.S.A.Tel: 1.408.752.0723 | Fax: 1.408.752.0724 | E-mail: ***********************Copyright RAE Systems Inc. | rev.2 wh 10-01F ACTS ABOUT PID M EASUREMENTSMiniRAE, ToxiRAE, ppbRAE, MultiRAE and ModuRAE VOC monitors are designed to provide continuous total organic vapor exposure monitoring in hazardous environments using a Photoionization Detector (PID). A few important factors affect the operation and measurement accuracy of PID instruments. These factors are explained below:1) Accuracy: The specified measurement accuracy (e.g.,±2 ppm or 10% of reading, whichever is greater) is defined for a single gas (e.g., isobutylene) obtained after the unit is calibrated with zero gas and isobutylene gas. The isobutylene calibration gas is balanced with air and is accurate to within 100±2% or 2 ppm, or 10±10% or 1 ppm. The measurement accuracy specification applies to bottled isobutylene gas only. For other organic gases and vapors, the specifiedmeasurement accuracy can be achieved if the specific gas of interest is used as calibration gas and the relative sensitivity of this particular gas is similar to that of isobutylene.2) Correction Factor: The correction factors (CFs) inTechnical Note 106 ( ) provide a convenient way to obtain approximate readings of other organic gases, when only isobutylene calibration gas isavailable. Refer to the instrument manual for the procedures to do so. Please note that using the CF will not achieve thespecified accuracy. This is because are accurate to about 20% and may change slightly with age and cleanliness of the lamp and with concentration. Such factors become more pronounced when the CF is much greater than 1. The instrument sensitivity can be estimated by multiplying the correction factor by 0.1. Therefore, a compound with CF of 10 will have a resolution of about 1 ppm instead of 0.1 ppm.3) Limitation of Gas Detection: A PID cannot detect allorganic vapors present. In general, if the Ionization Energy (IE, formerly ionization potential or IP) of a given compound is higher than that of the UV lamp energy (9.8, 10.6 or 11.7eV), it cannot be measured by a PID.4) Mixtures of Chemical Vapors: The PID detectorcannot distinguish one ionizable gas from another. Therefore, if there is more than one compound present, the PID will not provide an accurate concentration of a particular gas. It will give an approximate reading of total gas concentration.5) Humidity and Interference from other gases: In realapplications, the humidity level and the presence of other non-ionizable gas (such as methane) can reduce the sensitivity of the PID. It has been observed that the water vapor can reduce the instrument response by 50% when the relative humidity level is increased from 10% to 90%. This is because high concentrations of water molecules or other non-ionizable gas molecules block out some of the UV light. This well-knowneffect is called "quenching" and occurs with most existing photoionization detectors. Methane at 10 vol% reduces the response by a factor of about five, and most organiccompounds very high concentrations have similar effects. Many inorganic gases including argon, oxygen, nitrogen, hydrogen, and carbon dioxide have little or no effect on PID response and the PID can be used to measure contaminants in nearly pure streams of these gases.On the RAE PIDs, the detector chambers are specially designed to minimize the "quenching" effect. In addition, membrane filters are used to remove any moisture droplets from the incoming gas stream. As a result, RAE PIDs show improved response at high humidity and high concentration of non-ionizable gases.The following figure shows the humidity response ofMiniRAE 2000. The horizontal axis is the relative humidity and the vertical axis is the relative response of the PID instrument . Curves for ppbRAE and ToxiRAE are similar, although the effect is somewhat less for the ToxiRAE PID.6) Very High Concentration of Gases : When the VOCconcentration exceeds a few thousand ppm, the PID response "flattens out" because some of the gas molecules are blocked from the UV light source and can’t be ionized. This is a “self-quenching” effects similar to the quenching effects of water vapor or methane at high concentrations. This downward curvature is compensated by the instrument firmware to greatly improve the linearity, but the measurement errorincreases above a few thousand ppm. Therefore, to obtain the specified accuracy in high concentration range, the monitor should be calibrated using a similarly high concentration gas or use a dilution device at the input of the gas stream.。

中石化中石化空瓶的标准重量

中石化中石化空瓶的标准重量英文回答：The standard weight of Sinopec empty bottles varies depending on the type of bottle. As a Sinopec employee, I have encountered and handled different types of empty bottles and can provide some examples.For example, the standard weight of a 5-gallon polycarbonate bottle used for storing drinking water is approximately 700 grams. This type of bottle is commonly used in households and offices for water dispensers. When empty, it is lightweight and easy to handle.On the other hand, the standard weight of a 20-liter metal drum used for storing industrial chemicals is around 7 kilograms. These drums are much heavier due to their sturdy construction and the materials they are designed to contain. They are commonly used in factories and warehouses for storing and transporting various chemicals.It is important to note that these are just a few examples, and there are many other types of Sinopec empty bottles with different standard weights depending on their purpose and materials. The weight of the empty bottle is determined based on factors such as its size, material, and intended use.中文回答：中石化空瓶的标准重量因瓶子的类型而异。

Simultaneous Purification of Pulchinenoside B4 and B5 from Pulsatilla

© 2012 American Chemical Society
of target ingredients from complex extracts.12−18 On the other hand, polyacrylate resins, providing special hydrogen-bonding interactions with adsorbents, are suitable for the separation of phenolic acid and polyphenols,19−21 alkaloids,22 and dye ions, etc.23,24 As each type of resin has its own characteristics, it is critical to explore the suitable resins with speciﬁc features for the enrichment of target ingredients from various herbal extracts. To obtain pure ingredients frequently demanded in pharmaceutical applications, multiple-stage separation methods, such as various column chromatographies and crystallization techniques, are usually exploited.25−30 Preparative HPLC was applied as a powerful technique for the puriﬁcation of natural products,31 owing to its high eﬃciency, selectivity, and degree of automation. HPLC columns with traditional packing became nonhomogenous with time during the process of scale-up separation due to progressive consolidations of column beds. This phenomenon is resulted from repeated thermal expansion/ contraction, pump pulsations, etc. In contrast, dynamic axial compression (DAC) column, which was axially compressed under constant pressure to maintain a stable bed, ran well with good eﬃciencies and repeatability. DAC columns have been widely adopted in preparative HPLC separation procedures.31,32 In this study, a systematic preparative method was developed for the simultaneous puriﬁcation of performance of nine types of MARs was critically evaluated by static and dynamic absorption/desorption experiments to select the optimal resin. A second stage separation process was conducted to obtain both target compounds with high purity by

外贸英语口语电子书

一．对外贸易和对外贸易关系（一）They mainly trade with Japanese firms.他们主要和日本商行进行贸易。

For the past five years, we have done a lot of trade with your company.在过去的五年中，我们与贵国进行了大量的贸易。

Our trade is conducted on the basis of equality.我们是在平等的基础上进行贸易。

There has been a slowdown in the wool trade with you.和你们的羊毛贸易已有所减少。

Our foreign trade is continuously expanding.我们的对外贸易不断发展。

Trade in leather has gone up (down) 3%.皮革贸易上升（下降）了百分之三。

Trade in general is improving.贸易情况正在好转。

Our company mainly trades in arts and crafts.我们公司主要经营手工艺品。

They are well-known in trade circles.他们在贸易界很有名望。

We trade with people in all countries on the basis of equality and mutual benefit.我们在平等互利的基础上和各国人民进行贸易。

To respect the local custom of the buying country is one important aspect of Chinas foreign policy.尊重买方国家的风俗习惯是我国贸易政策的一个重要方面。

Our purpose is to explore the possibilities of developing trade with you.我们的目的是和你们探讨一下发展贸易的可能性。

(完整版)美国药典USP31(921)翻译版(下)

Method Ib (Residual Titration) 方法Ib（残留滴定）Principle— See the information given in the section Principle under Method Ia. In the residual titration, excess Reagent is added to the test specimen, sufficient time is allowed for the reaction to reach completion, and the unconsumed Reagent is titrated with a standard solution of water in a solvent such as methanol. The residual titration procedure is applicable generally and avoids the difficulties that may be encountered in the direct titration of substances from which the bound water is released slowly.原理：见方法Ia项下原理部分给出的信息。

在残留滴定中，额外的试剂被加入到供试样品中，为反应的完成留下了充分的时间，并且将未消耗掉的试剂与水和某种溶剂（例如，甲醇）的标准溶液一起滴定。

残留滴定程序通常是可行的，并避免了可能在直接滴定该物质过程中遇到的困难，这些物质中被束缚水分释放得很缓慢。

Apparatus, Reagent, and Test Preparation— Use Method Ia.仪器、试剂、供试配制液：同方法Ia。

Standardization of Water Solution for Residual Titration— Prepare a Water Solution by diluting 2 mL of water with methanol or other suitable solvent to 1000 mL. Standardize this solution by titrating 25.0 mL with the Reagent, previously standardized as directed under Standardization of the Reagent. Calculate the water content, in mg per mL, of the Water Solution taken by the formula:用于残留滴定的水溶液的标准化：以甲醇或其他适当溶剂将2mL水稀释至1000mL，以配制水溶液。

翻译2

7.1Introduction可能是最善意的化学治疗方案几乎没有代表性抽样毫无价值，然而，样品收集和运输上线的仪器，需要非常谨慎，代表性抽样的一些关键因素包括：。

提取样品散装的解决方案，使它代表了实际情况，在这个过程中流体;空调样本，以防止在采样线溶解成分的沉积;保持在一个合适的范围，以防止沉积或夹带的悬浮固体样品的线性速度，进一步空调样品压力和温度，准确的分析Ÿ行工具允许;图7.1和7.2显示采样系统的化学规范实地查看。

虽然抽样的某些方面有突出蜜蜂在前面的章节，下面的讨论提供了一个在这方面蒸汽发电化学更专注的神情。

7.2The需要采样由于许多历史案例说明，可能会发生化学搅得很突然。

除了在非常低的压力单位，研究生本身的抽样是不建议，因为这样只允许化学家获得“快照”的化学条件的意见。

在很大程度上可以发生在干预期间。

适当的化学控制，在线监测几乎已成为必不可少的。

这些分析表7.1通过7.2清单建议的采样点，电力和工业热电联产，蒸汽植物采样参数。

未必是绝对的要求，和这本书的读者可能会说赞成或反对一些分析，或有没有被提及。

然而，计划概述，将使蒸汽发电人员密切监察锅炉条件。

7.3Sample点选择下面的段落解释采样点的选择和分析背后的原因。

首先是一种常见的样本点和参数表中所列的讨论。

7.3.1化妆系统排放废水时，推荐的化妆系统的分析取决于类型的治疗方法。

对于阳离子/阴离子/混床除盐，阴离子的钠，二氧化硅，和电导率的污水分析提供了许多有意义的信息，并可以用来区分阳离子和阴离子的问题。

钠的水平升高表明用尽阴床。

如果阳离子床废气之前，阴床，阴离子污水的导电性会增加。

但是，如果前阴床的排气管排出的废气首先，电导率将DIP前短期内急剧增加。

混床出水的监测是更关键的是，混床是在治疗过程中的最后阶段，任何污染物将直接引入到锅炉给水系统。

典型的分析包括钠，二氧化硅和电导率。

表7.1蒸汽采样点效用鼓锅炉样品推荐点在线分析取样分析频率化妆系统出水钠硅规格分析和建议。

药物分析研究实验报告

个人收集整理仅供参考学习阿司匹林地质量分析一．实验目地1.掌握阿司匹林鉴定试验地原理及与药物结构地关系；2.掌握本实验中药物特殊杂质地来源和检查原理；3.掌握阿司匹林分析地条件及要点二．实验原理1.药物本品为白色片，遇湿气易变质. 本品含阿司匹林应为标示量地95.0%~105.0%.2.原理：⑴鉴别①三氯化铁反应 : 水杨酸及其盐在中性或弱酸性条件下，与三氯化铁试液反应，生成紫堇色配位化合物 . 阿司匹林加热水解生成水杨酸，可用三氯化铁反应鉴别. b5E2RGbCAP②水解反应 : 阿司匹林与碳酸钠试液加热，酯健水解，得水杨酸钠和醋酸钠，加过量稀硫酸酸化后，生成白色水杨酸沉淀，并发生醋酸地臭气，因此可用水解反应鉴别. p1EanqFDPw⑵ 检查阿司匹林中游离水杨酸地检查a.杂质来源游离水杨酸为阿司匹林生产中未反应地原料或贮存过程中地水解产物.b.检查方法阿司匹林无游离酚羟基，不与高铁盐溶液作用，而水杨酸则可与之反应生成紫堇色，此种方法称之对照法，极为灵敏，可检出 1ug 地游离水杨酸 . DXDiTa9E3d3.干燥失重测定法（1）定义：系指药品在规定地条件下，经干燥后所减失地量，以百分率表示 . 主要指水分，也包括其它挥发性物质 .（2 ）干燥失重测定法(中国药典2010年版二部附录ⅧL)有烘箱干燥法、恒温减压干燥法及干燥器干燥法，后者又分常压、减压两种. RTCrpUDGiT1）常压恒温干燥法：适用于受热较稳定地药物. 将供试品置相同条件下已干燥恒重地扁形称瓶中，于烘箱内在规定温度下干燥至恒重（两次干燥或炽灼后地重量差异在0.3mg 以下），从减失地重量和取样量计算供试品地干燥失重. 干燥温度一般为105℃. 5PCzVD7HxA2）干燥剂干燥法：适用于受热分解且易挥发地供试品 . 将供试品置干燥器中，利用干燥器内地干燥剂吸收水分至恒重 . 常用地有硅胶、硫酸和五氧化二磷 . jLBHrnAILg3）减压干燥法：适用于熔点低、受热不稳定及难赶除水分地药物 . 在减压条件下，可降低干燥温度和缩短干燥时间 . 减压后地压力在2.67kPa(20mmHg)以下 .xHAQX74J0X恒温减压干燥法烘箱干燥法干燥器干燥法4.炽灼残渣检查药品（多为有机化合物）经高温加热分解或挥发后遗留下不挥发地无机物，经加硫酸并炽灼（700~800℃）后生成金属氧化物或其硫酸盐即为炽灼残渣 . LDAYtRyKfE高温炉三．实验仪器与试剂㈠仪器高效液相色谱仪， 10~25ml 注射器， 0.8um 微孔滤膜，容量瓶，移液管，漏斗，扁形称量瓶，烘箱最高温度300℃，控温精度± 1℃，干燥器 ( 普通 ) ，分析天平感量0.1mg，高温炉，坩埚，坩埚钳等.剩余仪器如下图所示 . Zzz6ZB2Ltk㈡试剂1.三氯化铁试液取三氯化铁 9g，加水使溶解成100ml，既得 .2.碳酸钠试液取一水合碳酸钠12.5g 或无水碳酸钠 10.5g ，加水使溶解成100ml，既得 .3.稀硫酸取硫酸 57ml，加水稀释至 1000ml，既得 . 本液含硫酸应为9.5%~10.5%.阿司匹林、硫酸（分析纯）dvzfvkwMI1四．实验步骤（一）性状本品为白色结晶或结晶性粉末；无臭或微带醋酸臭，味微酸；遇湿气即缓缓水解 .本品在乙醇中易溶，在三氯甲烷或乙醚中溶解，在水或无水乙醚中微溶；在氢氧化钠溶液或碳酸钠溶液中溶解，但同时分解. rqyn 14ZNXI（二）鉴别（1）取本品约 0.1g ，加水 10ml，煮沸，放冷，加三氯化铁试液1滴，即显紫堇色 . EmxvxOtOco（2）取本品约 0.5g ，加碳酸钠试液 10ml，煮沸 2 分钟后，放冷，加过量地稀硫酸，即析出白色沉淀，并发生醋酸地臭气 . SixE2yXPq5（3）本品地红外光吸收图谱应与对照地图谱（《药品红外光谱集》5 图）一致 . 6ewMyirQFL（三）检查（1）溶液地澄清度取本品 0.50g ，加温热至约 45℃地碳酸钠试液10ml 溶解后，溶液应澄清 . kavU42VRUs（2）游离水杨酸取本品约 0.1g ，精密称定，置 10ml 量瓶中，加 1%冰醋酸甲醇溶液适量，振摇使溶解，并稀释至刻度，摇匀，作为供试品溶液（临用新制）；取水杨酸对照品约 10mg，精密称定，置 100ml 量瓶中，加 1%冰醋酸甲醇溶液适量使溶解并稀释至刻度，摇匀，精密量取 5 ml，置 50ml 量瓶中，用 1%冰醋酸甲醇溶液稀释至刻度，摇匀，作为对照品溶液 . 照高效液相色谱法（2010 年版药典二部附录Ⅴ D）试验 . 用十八烷基硅烷键合硅胶为填充剂；以乙腈－四氢呋喃－冰醋酸－水（ 20：5：5：70）为流动相；检测波长为 303nm.理论板数按水杨酸峰计算不低于 5000，阿司匹林峰与水杨酸峰地分离度应符合要求 . 立即精密量取供试品溶液、对照品溶液各 10μl ，分别注入液相色谱仪，记录色谱图 . 供试品溶液色谱图中如有与水杨酸峰保留时间一致地色谱峰，按外标法以峰面积计算，不得过 0.1%. y6v3ALoS89（3）干燥失重1.称取供试品取供试品，混合均匀( 如为较大地结晶，应先迅速捣碎使成2mm 以下地小粒 ) . 分取约 1g 或该药品项下所规定地重量，置与供试品同样条件下干燥至恒重地扁形称量瓶中( 供试品平铺厚度不可超过5m m，如为疏松物质，厚度不可超过 10mm) ，精密称定 . 干燥失重在1.0%以下地品种可只做一份， 1.0% 以上地品种应做平行试验两份.M2ub6vSTnP2.干燥除另有规定外，照各该药品项下规定地条件干燥. 干燥时，应将瓶盖取下，置称量瓶旁或将瓶盖半开. 取出时须将称量瓶盖好. 0YujCfmUCw3.称重用干燥器干燥地供试品，干燥后取出即可称定重量 .置烘箱或恒温减压干燥箱内干燥地供试品，应在干燥后取出置干燥器中放冷至室温 ( 一般约需 30~60 分钟 ) ，再称定重量 . eUts8ZQVRd4.恒重称定后地供试品按 (5.4.2~5.4.3)操作，直至恒重.5.记录与计算记录干燥时地温度、压力，干燥剂地种类，干燥和放冷至室温地时间，称量及恒重数据、计算和结果 ( 如做平行试验两份者，取其平均值) 等. sQsAEJkW5T式中 :W1为供试品地重量 (g) ; W2为称量瓶恒重地重量(g) ; W3为( 称量瓶 +供试品 ) 恒重地重量 (g). GMsIasNXkA6.干燥至恒重，除另有规定外，系指连续两次干燥后地重量差异在0.3mg 以下地重量 . 干燥失重过程中地第二次及以后多次称重，均应在规定条件下继续干燥 1 小时后进行 . TIrRGchYzg(4)炽灼残渣1.空坩埚恒重取坩埚置于高温炉内，将盖子斜盖在坩埚上，经 700-800 ℃炽灼约 60分钟，关闭电源，将炉门稍打开，待炉温降至约 400 ℃取出坩埚，移置干燥器内并盖上盖子，放冷至室温 ( 一般需 30~60 分钟 ) ，精密称定坩埚重量 . 再在上述条件下炽灼约 30 分钟，取出，置干燥器内，放冷至室温 ( 与上次放冷时间相同 ) ，称量，直至恒重，备用 . 以上炽灼操作也可借助煤气灯进行 . 7EqZcWLZNX2.称取供试品取供试品 1.0-2.0g或各该药品项下规定地重量，置已炽灼至恒重地坩埚内，精密称定 .3.炭化将盛有供试品地坩埚斜置电炉或煤气灯上缓缓灼烧( 避免供试品骤然膨胀而逸出 ) ，炽灼至供试品全部炭化呈黑色，并不冒浓烟，放冷至室温，“炭化”操作应在通风柜内进行 . lzq7IGf02E4.灰化除另有规定外，滴加硫酸 0.5-1.0ml ，使炭化物全部湿润，继续在电炉或煤气灯上加热至硫酸蒸气除尽，白烟完全消失 ( 以上操作应在通风柜内进行) ，将坩埚移置高温炉内，盖子斜盖于坩埚上，在700~800℃炽灼约 60 分钟，使供试品完全灰化 . zvpgeqJ1hk5.恒重按操作方法 1 自“取出坩埚稍冷片刻”起，依法操作，直至恒重. 以上炽灼操作也可借助煤气灯进行.五．注意事项（一）干燥失重1.由于原料药地含量测定，根据药典“凡例”地规定，应取未经干燥地供试品进行试验，测定后再按干燥品 ( 或无水物 ) 计算，因而干燥失重地数据将直接影响含量测定 ; 当供试品具有引湿性时，宜将含量测定与干燥失重地取样放在同一时间进行 . NrpoJac3v12. 供试品如未达规定地干燥湿度即融化时，应先将供试品于较低地温度下干燥至大部分水分除去后，再按规定条件干燥 . 1nowfTG4KI3.设定烘箱地温度时，应注意加热温度有冲高现象( 尤其干燥温度较低时) ，必要时可先设定至略低于规定地温度，待温度稳定后再调高至规定温度 . 也可借助程序升温方法 . fjnFLDa5Zo4.减压干燥，除另有规定外，压力应在2.67kPa(20mmHg)以下，并宜选用单层玻璃盖称量瓶，如用双层中空地玻璃盖称量瓶，减压时，称量瓶盖切勿放入减压干燥箱 ( 器) 内，应放另一普通干燥器内 . 减压干燥箱( 器) 内部为负压，开启前应缓缓旋开进气阀，使干燥空气进入，并避免气流吹散供试品 . tfnNhnE6e55.初次使用新地减压干燥器时，宜先将外部用较厚地布包好，再行减压，以防破碎伤人 .6. 恒温减压干燥时，除另有规定外，温度应为60 ℃. 装有供试品地称量瓶应尽量置于温度计部位，以避免因箱内温度不均匀造成地误差. HbmVN777sL7.干燥失重测定，往往几个供试品同时进行，因此称量瓶宜先用适宜地方法编码标记，以免混淆 ; 称量瓶放入干燥箱地位置，以及取出冷却、称重地顺序，应先后一致，则较易获得恒重 . V7l4jRB8Hs8. 称定扁形称量瓶和供试品以及干燥后地恒重，均应准确至0.1mg 位.( 二) 炽灼残渣1.供试品地取量应根据炽灼残渣限度来决定，一般规定炽灼残渣限度为 0.1~0.2%，应使炽灼残渣地量在1-2mg 之间，故供试品取量多为1.0~2.0g ，炽灼残渣限度较高或较低地药品，可酌情减少或增加供试品地取量 .83lcPA59W92.炽灼残渣检查同时做几份时，坩埚宜预先编码标记，盖子与坩埚应编码一致 . 坩埚从高温炉取出地先后次序，在干燥器内地放冷时间，以及称量顺序，均应前后一致 ; 每一干燥器内同时放置坩埚最好不超过 4 个，否则不易恒重 . mZkklkzaaP3.如需将炽灼残渣留作重金属检查，则炽灼温度必须控制在500~600℃.版权申明本文部分内容，包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts, including text,pictures, and design. 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1改性壳聚糖海藻酸钠聚合物吸附剂吸附除去镍离子

Modiﬁed chitosan and calcium alginate biopolymer sorbentsfor removal of nickel (II)through adsorptionY.Vijaya a ,Srinivasa R.Popuri b ,Veera M.Boddu c ,A.Krishnaiaha,*a Biopolymers and Thermophysical Laboratories,Department of Chemistry,Sri Venkateswara University,Tirupati 517502,IndiabDepartment of Chemistry,National Chung-Hsing University,Taichung 40227,Taiwan,ROCcU.S.Army Construction Engineering Research Laboratory,Engineer Research and Development Centre,Champaign,IL 61826,USAReceived 16April 2007;received in revised form 4August 2007;accepted 10August 2007Available online 17August 2007AbstractRemoval of nickel (II)from aqueous solutions through adsorption on to biopolymer sorbents,such as calcium alginate (CA),chitosan coated calcium alginate (CCCA)and chitosan coated silica (CCS),was studied using equilibrium batch and column ﬂow techniques.The biosorbents were characterized by FTIR,SEM,TGA and surface area analysis.The extent of adsorption was found to be a function of the pH of the solution,contact time,sorbate concentration and adsorbent dose.The optimum pH was found to be 5.0.The adsorption of Ni (II)ions on CA was comparatively higher than CCCA and CCS.Adsorption of Ni (II)on to the biopolymers followed pseudo-second order kinetics.The equilibrium adsorption data for Ni (II)on CA,CCCA and CCS were ﬁtted to Freundlich,and Langmuir Isotherms.The maximum monolayer adsorption capacity of the biosorbents (CA,CCCA and CCS),as obtained from Langmuir adsorption iso-therm,was found to be 310.4,222.2and 254.3mg/g,respectively.Breakthrough curves were obtained for adsorption of Ni (II)on all the three adsorbents through column ﬂow technique.The Ni (II)loaded biosorbents were regenerated using 0.1M EDTA solution.Ó2007Elsevier Ltd.All rights reserved.Keywords:Biosorption;Nickel;Chitosan;Calcium alginate;Silica1.IntroductionThe presence of heavy metal ions from the transition series,viz,Cu,Fe,Ni,and Pb etc.in the environment was of major concern due to their toxicity to many life forms.Many industrial processes such as mining,electro-plating,dyeing,paper and petroleum produce wastewater streams containing heavy metals which are toxic to living organisms (Gupta,Gupta,&Sharma,2001).Unlike organic pollutants,metallic pollutants released into the environment tend to persist indeﬁnitely,circulating and eventually accumulating throughout the food chain thus posing a serious threat to animals and man.Since the metal ions must be removed before discharge,an economical pro-cess for removing low levels of these heavy metals from such a large volume of waste stream was important.Precip-itation,oxidation and reduction,ion exchange,ﬁltration,reverse osmosis,electro-chemical removal,and evaporative recovery can all potentially be used to treat industrial eﬄuents for metals (Chong &Volesky,1995;Leusch,Holan,&Volesky,1995;Volesky,1999).These methods are ineﬃcient for heavy metal contaminants at tracer levels.Wastewater discharge from electroplating,electronics and metal cleaning industries often contain high concentrations of Ni (II)ions and causes serious water pollution.Many biopolymers such as sodium alginate,chitosan extracted from microalgae (Da Costa &Leite,1991),shrimp,crab,some fungi (Bosinco,Dambies,Guibal,Roussy,&Le Cloirec,1997;Jang,Lopez,Eastmen,&Pryf-ogle,1991)are known to bind metal ions strongly and could be used for heavy metal adsorption.Biopolymers are non-toxic,selective,eﬃcient and inexpensive and thus highly competitive with ion-exchange resins and activated carbon.Immobilizing biomass in a biopolymeric matrix may also improve biomass performance,biosorption0144-8617/$-see front matter Ó2007Elsevier Ltd.All rights reserved.doi:10.1016/j.carbpol.2007.08.010*Corresponding author.E-mail address:abburikrishnaiah@ (A.Krishnaiah)./locate/carbpolAvailable online at Carbohydrate Polymers 72(2008)261–271capacity and facilitate the separation of biomass from metal-bearing solutions.Alginate is a linear copolymer of a-L-guluronate(G)and a-D-mannuronate(M),which con-stitutes10–40%of the dry weight of all species of brown algae(Volesky,2003).The gelation properties of alginate can be attributed to the simultaneous binding of the diva-lent cations such as Ca2+to diﬀerent chains of a-L-guluro-nate blocks.As a result of their conﬁguration,these chains form electronegative cavities capable of holding the cations via ionic interactions,resulting in cross-linking of the chains into a structure resembling an‘‘egg box’’(Grant, Morris,Rees,Smith,&Thom,1973).Due to its ability to form stable structures,cross-linked alginate has been used for the removal of heavy metal from wastewater (Holan,Volesky,&Prasetyo,1993;Kuyucak&Volesky, 1989;Romero-Gonzalez,Williams,&Gardiner,2001). Although it has been demonstrated that the alginates pres-ent in algae are capable of binding heavy metals through carboxyl groups(Chen&Yiacoumi,1997;Ib´a˜nez&Ume-tsu,2002;Konishi,Asai,Midoh,&Oku,1993;Mimura, Ohta,Akiba,&Onodera,2001),very few studies have been conducted on the potential use of alginates as a sorbent for heavy metal removal from aqueous solutions.Chitosan appears to be a more economically attractive sorbent for removal of metallic ions from water,since it is obtained from chitin the second most abundant polymer in nature next to cellulose.Furthermore,chitosan has many useful features such as biocompatibility,biodegradability, and anti-bacterial properties.Chitosan is eﬀective in the uptake of transition metals since the amino groups on chito-san chains serve as coordination sites(Muzzarelli,1983). Several methods have been used to modify raw chitosan ﬂakes either by physical(Veera,Krishnaiah,Jonathan,& Edgar,2003;Yang&Yuan,2001;Zhang&Chen,2002)or chemical(Ho,Ng,&Me Kay,2001;Hsalah,Weber,&Vera, 2000;Zouboulis,Matris,Lanara,&Nescovic,1997)modiﬁ-cations in order to improve pore size,mechanical strength, chemical stability,and biocompatibility.In the present study,new biosorbents were developed by coating chitosan,a glucosamine biopolymer,on calcium alginate and silica to overcome some of the problems asso-ciated with the use of pure chitosan.The aim of the work was to prepare calcium alginate(CA),chitosan coated cal-cium alginate(CCCA)and chitosan coated silica(CCS) and to determine the ability of these biosorbents in remov-ing nickel(II)ion from aqueous medium under batch equi-librium and columnﬂow experimental conditions.Further the biosorbents were characterized by FTIR,SEM,TGA and surface area analysis to understand the surface morphology.2.Experimental2.1.MaterialsAnalytical grade nickel ammonium sulphate was pur-chased from S.D.Fine Chemicals for nickel(II)ion source.Hydrochloric acid and sodium hydroxide used for pH adjustment and for the preparation of beads were obtained from Aldrich Chemical Company and Chemical Drug House Ltd.Sodium alginate was obtained from Loba Chemie,and acetic acid and calcium chloride were purchased from S.D.Fine Chemicals.Chitosan, with an average molecular weight of500,000and84% of degree of deacetylation,and silica gel were obtained from Aldrich Chemical Company.Double distilled water of conductivity<0.02S/cm was used throughout this work.2.2.Preparation of biosorbent beads2.2.1.Calcium alginate beadsSodium alginate solution was prepared by dissolving and gently heating4g of alginate in96ml of water.The solution was then dropped into2%calcium chloride solu-tion through the tip of the transfer pipette.The drops of sodium alginate solution gelled into3.5±0.1mm diameter beads upon contact with calcium chloride solution.The beads were kept in contact with calcium chloride solution for4h,which lead to the formation of insoluble and stable beads.Water soluble sodium alginate was converted to water insoluble calcium alginate(CA)beads using CaCl2 solution.The beads were rinsed with double distilled water and dried until the water was completely evaporated.It was observed that the size of the beads decreases on drying. Five diﬀerent beads of the completely dried sample were taken randomly and the size of the each bead was mea-sured by using the micrometer screw gauge with an accu-racy of±0.01mm.The average size of the bead was found to be2.05mm.2.2.2.Chitosan coated calcium alginateThe calcium alginate beads were dropped in to a4% chitosan gel,prepared by dissolving4g of chitosan in 100ml of2%acetic acid solution and stirred for about 12h.Then the beads covered with chitosan were trans-ferred into a500ml of0.1M NaOH solution and allowed to stand for about4h.Generally,chitosan is soluble in weak acids and insoluble in alkaline medium.The beads were removed from the alkali,thoroughly washed with double distilled water until the washings were neutral and dried.2.2.3.Chitosan coated silicaTen grams of silica,washed with2%acetic acid solution, were added to100ml of4%chitosan gel while stirring with a magnetic stirrer for4h.This process led to the formation of a silica/chitosan suspension.This suspension was dropped into500ml of0.1M NaOH solution while stirring to neutralize excess acid.The suspension was converted into pellets.The pellets were washed with double distilled water until the washings were neutral.The material was crushed,sieved and particles with100mesh size were used as the biosorbent.262Y.Vijaya et al./Carbohydrate Polymers72(2008)261–2712.3.Equilibrium adsorption studiesAn adsorbate stock solution of1000mg/L of nickel(II) was prepared by dissolving6.73g of nickel ammonium sul-phate in double distilled water.This stock solution was diluted to the required concentration(50–500mg/L of Ni (II)).Equilibrium batch adsorption experimental studies were carried out with known weight(150mg)of adsorbent and100ml of nickel(II)stock solution of desired concen-tration at optimum pH(5.0)in125ml stopper bottles.The bottles were agitated at160rpm for150min time intervals at room temperature in a mechanical shaker.After attain-ing equilibrium,the biosorbent was separated byﬁltration and the aqueous-phase concentration of metal was ana-lyzed with Atomic Absorption Spectrophotometer(Per-kin-Elmer2380).The equilibrium uptake capacity for each sample was calculated according to mass balance on nickel ions;q e ¼C iÀC emVð1Þwhere C i and C e were,respectively,initial and equilibrium concentrations of metal ion,m was the mass of adsorbent and V was volume of the solution in liters.Experiments were conducted with metal ion solution in the absence of adsorbent and it was found that there was no metal adsorp-tion by the walls of the container.2.4.Column adsorption studiesColumnﬂow adsorption experiments were conducted in a glass column of about2.5cm internal diameter and10cm length.The column wasﬁlled with a known weight of the adsorbent while tapping the column such that the column wasﬁlled without voids.The adsorbate solution was allowed toﬂow through the column at a constantﬂow rate (2ml/min)throughout the experiment.The pH of the inlet solution was adjusted to5.0at the start of the experiment. The eﬄuent solution was collected at diﬀerent time inter-vals and the concentration of Ni(II)ion in the eﬄuent solution was monitored by Atomic Absorption Spectro-photometer.The solutions were diluted appropriately prior to analysis.Samples at10min time intervals from the start of the experiment were collected for analysis.Column stud-ies were conducted for the three adsorbents(CA,CCCA and CCS).Breakthrough curves for each adsorbent indi-vidually were obtained by plotting the volume of the solu-tion against the ratio of the concentration of eﬄuent at any time(C e)to that of the inlet solution(C0),C e/C0.2.5.Desorption studiesThe desorption(recovery)studies are very important since the economic success of the adsorption process depends on the regeneration of adsorbent.There are sev-eral methods for desorption of the adsorbate from the loaded adsorbents.In the present study,the elution method with solvent was used to remove the adsorbed metal ions from adsorbents.Several solvents/solutions were tried to regenerate the biosorbents.Out of several solvents/solu-tions,0.1M ethylenediamine tetraacetic acid(EDTA)solu-tion was found to be eﬀective in desorbing Ni(II)ions from the loaded adsorbents.The column was regenerated using 0.1M EDTA solution,when the concentration of the eﬄu-ent solution was close to the inlet concentration.The remaining aqueous solution was drained from the column by pumping air.Then EDTA solution was passed in to the column at aﬁxedﬂow rate and the concentration of the solution coming out of the column was monitored. 2.6.Characterization of biosorbentsThe biosorbents were characterized using FTIR spectra, SEM micrograph,thermogravimetric and surface analysis. FTIR spectra of biopolymers were recorded in a Perkin-Elmer-283B FTIR spectrometer over the wave range 4000–400cmÀ1.The samples were prepared as KBr discs. SEM photographs were taken with JSM6700F Scanning Microscope to examine the morphology and surface struc-ture of the beads at the required magniﬁcation at room temperature.The beads were deposited on a brass hold and sputtered with a thin coat of gold under vacuum. Acceleration voltage used was20kV with the secondary electron image as a detector.Thermal gravimetric analyses (TGA)were performed on freeze-dried CA,CCCA and CCS samples using Mettler Thermal Analyzer TG-50in the temperature range of30–400°C at a heating rate of 10C/min with nitrogenﬂushed at200ml/min.Surface area of the biosorbents was measured by single point BET(Bru-nauer,Emmett and Teller)method using thermal conduc-tivity detector(Carlo Erba Soptomatic–1800)within the range of0.1–2000m2gÀ1and with the sample size of2–10mg.Pycnomatic ATC was uniquely designed for density measurement of solid and powder samples.Pore volume of the biosorbent samples was measured using Pycnomatic ATC(Thermo Electronic Corporation).3.Result and discussion3.1.FTIR spectraThe FTIR spectra of CA,CCCA and CCS are shown in Fig.1in both pristine and metal loaded forms.The IR spectrum of pristine calcium alginate(Fig.1a)shows absorption bands at3430cmÀ1(OH stretching), 1618cmÀ1(COOÀasymmetric stretching),and1429cmÀ1 (COOÀsymmetric stretching).The bands at1125cmÀ1 are due to the–C–O stretching of ether groups and the bands at1065cmÀ1are assigned to the–C–O stretching of alcoholic groups.Fig.1b shows the FTIR spectrum of CA loaded with Ni(II)ions.An interesting phenomenon is the sharp shift in the position and intensity of the bands after metal binding.The FTIR spectrum of CCCA biosor-bent in Fig.1c indicates the presence of predominant peaksY.Vijaya et al./Carbohydrate Polymers72(2008)261–271263at 3352cm À1(–OH and –NH stretching vibrations),2987cm À1(–CH stretching vibration),1568cm À1(–NH bending vibration),1393cm À1(–NH deformation vibra-tion),and 1065cm À1(–CO stretching vibration).This reveals that all functional groups originally present on chitosan and alginate are still present even after coating process and are available for interaction with Ni (II)ions.Fig.1d represents the FTIR spectra of Ni (II)loaded CCCA,indicating the shift in the position and intensityof the peaks upon metal binding.Chitosan coated silica shows a peak (Fig.1e)at the wave number 797cm À1(C–H group out of plane).A broad peak at around 1092cm À1may be due to the merging of peaks relating to Si–O–Si,Si–O–H,C–O groups.Another broad peak around 3439cm À1is attributed to –NH and O–H stretch-ing vibrations.The FTIR spectrum of Ni (II)loaded CCS (Fig.1f)indicates the considerable change in the posi-tion and intensity of the peaks.From these observations it may be concluded that –NH 2,–OH,–CO and –SiO act as binding sites for Ni (II)ion adsorption on the biosorbents.The study of Chui et al.(Chui,Mok,Ng,Luong,&Ma,1996)conﬁrmed that the amino groups of chitosan are the major eﬀective binding sites for metal ions,forming stable complexes by coordination.The nitrogen electrons present in the amino groups can establish dative bonds with transitional metal ions.Some hydroxyl groups in these biopolymers may function as donors.Hence,deprotonated hydroxyl groups are involved in the coordination with metal ions (Lerivrey,Dubois,Decock,Micera,&Kozlow-ski,1986).It was established that chitosan forms chelates with metal ions by releasing hydrogen ions (Inoue,Baba,Yoshizuka,Noguchi,&Yoshizaki,1988).Formation of a complex between chitosan and Ni (II)is shown in Fig.2.3.2.Surface morphologyThe SEM images of the surface of CA,CCCA and CCS,shown in Fig.3,display a rough structure on surface with a large surface area.An examination of the SEM micro-graphs (Fig.3a and b)indicates the presence of many pores and also some cracks on the surface of the biosorbents.It also shows the surface condition on chitosan coated beads is somewhat swollen during the contact with nickel ion solution.The results from TGA are presented in Figs.4–6for CA,CCCA and CCS in the form of thermograms.Chitosan has two main decomposition stages with one starting at 238°C and another starting at around 320°C (Ding,Qing Lian,Samuels,&Polka,2003).Thermal behavior of CA and CCCA is not much diﬀerent,where as CCS behaves diﬀerently.The two weight losses in the case of CA and CCCA occur at around 235°C(aboutFig.1.FTIR spectra of (a)CA,(b)CA loaded with Ni (II),(c)CCCA,(d)CCCA loaded with Ni (II),(e)CCS,(f)CCS loaded with Ni (II).Fig.2.Formation of complexation between chitosan and Ni (II).264Y.Vijaya et al./Carbohydrate Polymers 72(2008)261–27116%)and 318°C (about 40%).The thermogram of CCS shows a broad transition with a relatively less weight loss.The weight loss is about 3%around 150°C and about 6%at 360°C.Thermogram of CCS indicates that about 8%of chitosan is coated on silica.From the TGA analyses of thebiosorbents,it may be concluded that the biosorbents could be used even at higher temperatures in water treatment.Surface area and pore volume values were presented in Table 1.Among the three biosorbents,the CA possesses high surface area and pore volume when compared to the other two sorbents.Obviously the metal uptake capacity of this sorbent will be high due to its free hydroxyl groups.3.3.Eﬀect of pHThe most important parameter inﬂuencing the biosorp-tion rate and capacity is the pH of the biosorption medium.To evaluate the eﬀect of pH on nickel (II)sorption capacity on the biopolymer adsorbents,experiments were conducted with 100ml of 100mg/L of metal solution containing 150mg of adsorbent in the pH range 2–6at room temper-ature.It was observed that biosorption rate increases as the pH of adsorption medium increases.The inﬂuence of pH was not studied beyond 6.0due to the formation of precip-itate.Fig.7depicts the eﬀect of pH on the adsorption of Ni (II)ion on CA,CCCA and CCS.The optimum pH for all the three sorbents was found to be 5.0for nickel (II)ion adsorption.The eﬀect of pH on adsorption capacity may be dis-cussed on the basis of the nature of the chemical interac-tions of Ni (II)ions with the biosorbents.The carboxylic (–COOH)and amino (–NH 2)groups present on the biosor-bents are responsible for the binding of nickel (II).At lower pH,the carboxylic groups retain their protons and amino groups get protonated,thereby,reducing the probability of binding to any positively charged ions.Whereas at higher pH (above 4.0),the COO Àions,formed due to dis-sociation of carboxylate groups,and the free amino groups attract the positively charged Ni (II)ions.This results in an increase of adsorption.According to Low et al.(Low,Lee,&Tan,1995),at low pH values the surface of adsorbent would be closely associated with hydronium ions (H 3O +),which hinder the access of the metal ions to the surface functional groups.Consequently,the percentage of metal ion removal is relatively small at lower pH.The low level of nickel (II)uptake at lower pH values could also be attributed to the increased concentration of hydronium (H 3O +)ions competing for nickel (II)binding sites on the biomass.3.4.Adsorption kineticsTo understand the eﬀect of time on the extent of adsorp-tion,equilibrium concentrations of Ni (II)ions were deter-mined at diﬀerent time intervals with initial concentrations of 100,250and 500mg/L,keeping the pH and amount of biosorbent constant.The results are graphically presented in Figs.8–10for CA,CCCA and CCS.The adsorption eﬃ-ciency of all the three biosorbents (CA,CCCA and CCS)increased with time and attained equilibrium within 90min.The data were used to study the kinetics ofadsorp-Fig.3.SEM images of (a)CA,(b)CCCA and (c)CCS.Y.Vijaya et al./Carbohydrate Polymers 72(2008)261–271265tion of Ni(II)on biosorbents.Kinetics of adsorption using diﬀerent models was studied by many workers(Aksu,2002; Donmez&Aksu,2002;Rangsayatorn,Upatham,Kruatra-chue,Pokethitiyook,&Lanza,2002).In order to investi-gate the mechanism of sorption,the rate constants for the nickel ion adsorption were determined by using Lager-gren and a pseudo-second order equations.The Lagergrenﬁrst order kinetic equation isd qed t¼k1ðq eÀq tÞð2ÞLinearized form of the above equation islogðqe Àq tÞ¼log q eÀk12:303tð3Þwhere q e and q t are the amounts of solute adsorbed per unitmass of the adsorbent(mg/g)at equilibrium time and timet(min),respectively,and k1is the rate constant(minÀ1).The straight line plots of log(q eÀq t)against t are used todetermine the rate constant,k1and correlation coeﬃcients,R2for diﬀerent concentrations.The pseudo-second order equation(Ho,2003)may beexpressed asd qed t¼k2ðq eÀq tÞ2ð4ÞLinearized form of the above equation istqt¼1k2q2eþtqeð5ÞFig.4.Thermogravimetric curve of calciumalginate.Fig.5.Thermogravimetric curve of chitosan coated calcium alginate.266Y.Vijaya et al./Carbohydrate Polymers72(2008)261–271where k 2is the rate constant of second order adsorption (g mg À1min À1).The straight line plots of t /q t against t are used to obtain rate parameters.The rate constants of Lagergren and pseudo-second order kinetic models are shown in Tables 2and 3.The ﬁrst order kinetic process has been used for the description of reversible equilibrium between liquid and solid phases whereas,the second order kinetic model assumes that the rate limiting step may be chemical adsorption (Ho &McKay,2000).In many cases,the adsorption data are well correlated by the second order equation (Wu,Tseng,&Juang,2000).An examination of the values in thetablesFig.6.Thermogravimetric curve of chitosan coated silica.Table 1Surface area and pore volume values of the adsorbents Biosorbent Pore volume (cc)Surface area (m 2/g)CA 0.231178.3CCCA 0.202144.6CCS0.224160.8Y.Vijaya et al./Carbohydrate Polymers 72(2008)261–271267indicates that the adsorption of Ni(II)on the biosorbents follows the second order kinetic model.In many cases the ﬁrst order equation of Lagergren is generally applicable over the initial stage of adsorption process and fails to rep-resent the adsorption data over the whole range of contact time.3.5.Eﬀect of biosorbent doseThe dependence of Ni(II)sorption on biosorbent dose was studied by varying the amount of adsorbent from 0.05to0.5g while keeping all other variables(pH,agita-tion time and concentration(100mg/L))constant.The results are presented in Fig.11,which indicates that removal eﬃciency of the adsorbent increases with increas-ing adsorbent dose.This is expected due to the fact that the higher dose of adsorbent in the solution results in greater availability of exchangeable sites for the ions.The maximum nickel(II)ion removal eﬃciencies are96%with CA,94%with CCCA and91%with CCS.This suggests that the Ni(II)ion can be removed eﬀectively by using <1gm of the biosorbent.3.6.Adsorption isothermsOut of several isotherm equations,the Freundlich and Langmuir isotherms were used toﬁt the experimental data. The variation of the extent of adsorption with concentra-tion of Ni(II),included in Fig.12,shows that the sorbents exhibit high metal uptake capacity at higher initial concen-tration.The Langmuir isotherm assumes a surface with homogeneous binding sites,equivalent sorption energies, and no interaction between sorbed species.In mathemati-cal form,it is written asqe¼Q0bC eð1þbC eÞð6Þ1qe¼1Q0bC eþ1Qð7Þwhere q e is the speciﬁc metal uptake,Q0the maximum adsorption capacity in mg/g,C e the equilibrium concentra-tion in mg/L,and b relates to the aﬃnity of the sorbate for the binding sites expressed in L/mg.The Freundlich isotherm is an empirical equation based on an exponential distribution of sorption sites and ener-gies.In mathematical form,it is represented asqe¼K f C1=neð8Þlog qe¼log K fþ1nlog C eð9Þwhere K f and1are related to the sorbent capacity and sorp-tion intensity,respectively.Though both Langmuir and Freundlich isotherms are capable of representing the data satisfactorily(Figs.13Table3Pseudo second order rate constants for adsorption of nickel(II)on CA, CCCA and CCSBiosorbent Concentration of nickel(II)solution(mg/L)100250500k2(mgÀ1 g minÀ1)R2k2(mgÀ1g minÀ1)R2k2(mgÀ1g minÀ1)R2CA 1.15·10À30.988 2.81·10À30.995 1.96·10À30.996 CCCA0.40·10À30.9990.48·10À30.9970.44·10À30.997 CCS0.20·10À30.9970.27·10À30.9960.23·10À30.996Table2Lagergrenﬁrst order rate constants for adsorption of Ni(II)on CA,CCCA and CCSBiosorbent Concentration of nickel(II)solution(mg/L)100250500k1(minÀ1)R2k1(minÀ1)R2k1(minÀ1)R2CA0.0240.9860.0400.9880.0520.982CCCA0.0330.9870.0340.9830.0380.997CCS0.0200.9910.0250.9940.0300.985268Y.Vijaya et al./Carbohydrate Polymers72(2008)261–271and14),the Langmuir model gives a better representa-tion.The values of Langmuir and Freundlich constants are given in Table4.The Langmuir parameter,b,can be used to predict the aﬃnity between the sorbate and sorbent using the dimensionless separation factor,R L, deﬁned by Hall et al.(Hall,Eagleton,Acrivos,&Verme-ulen,1966)asR L¼11þbC0ð10Þwhere C0is the initial Ni(II)concentration(mg/L)and b is the Langmuir adsorption equilibrium constant(L/mg).If the R L values are equal to zero or one,the adsorption is either linear or irreversible,and if the values are in between zero and one,adsorption is favorable to chemisorption. The values of R L for sorption of nickel on CA,CCCA and CCS are less than1and greater than0,indicating the favorable uptake of Ni(II)by all the biosorbents. 3.7.Column studiesColumn adsorption studies were performed under the optimum conditions with aﬂow rate of2ml/min and inlet nickel(II)concentration of100mg/L.The total amount of nickel(II)adsorbed for a given feed concentration andﬂow rate was calculated from the area under the breakthrough curve.The maximum speciﬁc nickel(II)uptake is deﬁned as the total amount of metal ion sorbed for a gram of bio-sorbent in the packed bed at the end of totalﬂow time. Breakthrough curves were obtained by plotting the nor-malized concentration deﬁned as the ratio of eﬄuent nickel (II)ion concentration to inlet nickel(II)ion concentration (C e/C0)as a function of eﬄuent volume.Adsorption breakthrough curves obtained for diﬀerent biosorbents are given in Fig.15.As can be seen inTable4Langmuir and Freundlich isotherm constants for adsorption of nickel(II)on CA,CCCA and CCSBiosorbent Q0(mg/g)b(L/mg)R2K F(L/g)n R2CA310.40.36·10À20.9900.9310.8540.986CCCA222.20.24·10À10.99011.988 2.1290.973CCS254.30.26·10À20.9947.693 1.3250.976 Y.Vijaya et al./Carbohydrate Polymers72(2008)261–271269。