皮革中铬含量的测定任务书

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出口皮革手套中铬(VI)的检验方法分光光度法

出口皮革手套中铬(VI)的检验方法分光光度法Method for the determination of chromium(VI) in leather gloves for export—SpectrophotometrySN 0704—1997 前言本标准是根据GB／T1.1—1993《标准化工作导则第1单元：标准的起草与表述规则第l部分：标准编写的基本规定》及SN／T 0001—1995《出口商品中农药、兽药残留量及生物毒素检验方法标准编写的基本规定》的要求进行编写的。

其中测定方法是采用prEN420：1992标准中铬(VI)测定方法，技术内容与原方法相同，经验证后，按规定格式要求做了编辑性修改。

本标准中同时制定了抽样和制样方法。

测定低限是根据prEN420：1992对皮革手套中铬(VI)的最高限量和测定方法的灵敏度而制定的。

本标准的附录A为提示的附录。

本标准由中华人民共和国国家进出口商品检验局提出并归口。

本标准由中华人民共和国广东进出口商品检验局负责起草。

本标准主要起草人：蒋瑾华、蔡纯、易蓉。

本标准系首次发布的行业标准。

1 范围本标准规定了出口皮革手套中铬(VI)检验的抽样、制样和分光光度测定方法。

本标准适用于出口皮革手套中铬(VI)的检验。

2 抽样和制样2.1 检验批2.1.1 手套原料皮革以同一生产批的不超过5000张为一检验批。

2.1.2 手套成品以不超过1000箱为一检验批。

同一检验批的商品应具有相同特征，如包装、标记、产地、规格和等级等。

2.2 抽样数量2.2.1 手套原料皮革按式(1)计算抽取张数： (1)式中：n—抽样张数；N—同一检验批皮革的总张数。

注：n值取整数，小数部分向前进位为整数。

在任何情况下，取样量不得少于3张。

2.2.2 手套成品批量，件最低抽样数，件1～10111～20221～50351～1005101～5007501～100092.3 抽样工具割刀、剪刀。

皮革化学试验六价铬的测定

皮革化学试验六价铬的测定1 方法来源参照DIN 53314。

2适用范围适用于皮革。

3测定方法3.1原理六价铬在磷酸介质中和二苯碳酰二肼定量生成紫红色的物质，用分光光度计测定。

3.2 试剂3.2.1 磷酸氢二钾缓冲溶液：1mol/L配制：称取K2HPO4.3H2O 22.8g配成100mL。

3.2.2 磷酸溶液：7:3配制：移取70mL磷酸（比重1.71，85％），用水稀至100mL。

3.2.3 显色剂的配制配制：称取1g二苯碳酰二肼（C13H14N4O）简称D.P.C，溶于100mL丙酮溶液中，加1滴醋酸溶液酸化。

二苯碳酰二肼贮于棕色瓶中，于（2～8）℃保存，最多可以存放14天，如呈现显著的变色（特别是玫瑰色），需重新配制。

3.2.4六价铬标准曲线的制作3.2.4.1 六价铬标准溶液的配制称取于（102±2）℃干燥（16±2）h的重铬酸钾0.283g，配成1000mL （0.1mg/mL六价铬标准溶液）。

吸取该溶液10mL，配成1000mL（1μg/mL六价铬标准溶液）。

3.2.4.2 六价铬标准曲线的绘制移取1μg/mL六价铬标准溶液0、1、2......10 mL，置于50 mL的容量瓶中，加入1 mL7：3磷酸溶液和1mL二苯碳酰二肼显色剂，加水到刻度，静置15分钟，同时做空白试验。

在540nm处测其吸光度。

以六价铬浓度（μg/50mL）为横坐标，相对应的吸光度为纵坐标，绘制标准曲线。

2.2.4.3皮革中六价铬含量的测定：在具塞三角瓶中加入1mol/L磷酸氢二钾缓冲溶液10mL和蒸馏水90mL，再加入7：3磷酸1滴（该溶液的pH值应在8.0±0.1，如不在该pH值范围，需调节）。

依据DM-CZ 05-505进行试样的准备。

称取准备好的革样2g于上面磷酸氢二钾缓冲溶液的三角瓶中，盖好盖，置于振荡器上，温度控制在18～28℃之间，调节振荡器的频率为（100±5）次/分，使得溶液中的皮革作轻微运动，振荡3h±5min。

DIN EN ISO17075 皮革--化学试验--铬(VI)含量的测定德国版

February 2008DEUTSCHE NORMEnglish price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut für Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).!$LHB"1413731www.din.de©www.beuth.deDIN EN ISO 17075:2008-022 National forewordThis standard has been prepared by Technical Committee CEN/TC 289 “Leather” (Secretariat: UNI, Italy), in collaboration with Technical Committee ISO/TC IULTCS (Chemical Test Commission of the International Union of Leather Technologists and Chemists Societies).The responsible German body involved in its preparation was the Normenausschuss Materialprüfung (Materials Testing Standards Committee), Technical Committee NA 062-05-52 AA Chemische Prüfverfahren für Leder.The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 2418DIN EN ISO 2418 ISO 3696DIN ISO 3696 ISO 4044DIN EN ISO 4044 ISO 4684DIN EN ISO 4684Amendments This standard differs from DIN 53314:1996-04 and DIN CEN/TS 14495:2003-08 as follows:a) The number of the standard has been changed.b) Subclause 7.2 “Preparation of analytical solution” has been modified.Previous editionsDIN 53314: 1996-04DIN CEN/TS 14495: 2003-08National Annex NA (informative) Bibliography DIN EN ISO 2418, Leather — Chemical, physical and mechanical and fastness tests — Sampling location DIN EN ISO 4044, Leather — Chemical tests — Preparation of chemical test samplesDIN EN ISO 4684, Leather — Chemical tests — Determination of volatile matterDIN ISO 3696, Water for analytical laboratory use — Specification and test methodsw w w .b z f x w .c o mEUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN ISO 17075November 2007ICS 59.140.30Supersedes CEN/TS 14495:2003English VersionLeather - Chemical tests - Determination of chromium(VI)content (ISO 17075:2007)Cuir - Essais chimiques - Détermination de la teneur enchrome(VI) (ISO 17075:2007)Leder - Chemische Prüfungen - Bestimmung des Chrom(VI)-Gehalts (ISO 17075:2007)This European Standard was approved by CEN on 24 October 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONC O M I T É E U R O P ÉE NDE N O R M A LI S A T I O NEUR OP ÄIS C HES KOM ITEE FÜR NOR M UNGManagement Centre: rue de Stassart, 36 B-1050 Brussels © 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 17075:2007: E w w w.b z f x w .c o m2 DIN EN ISO 17075:2008-02EN ISO 17075:2007 (E)ContentsPageForeword (6)1 Scope (4)2 Normative references (4)3 Terms and definitions ........................................................................................................................ 4 4 Principle .. (4)5 Reagents (5)6 Apparatus (5)7 Procedure (6)7.1 Sampling and preparation of samples (6)7.2 Preparation of analytical solution (6)7.3 Determination of chromium(VI) in the solution obtained from the extraction procedure (6)7.4 Blank solution (7)7.5 Calibration (7)7.6 Determination of the recovery rate (7)7.6.1 Influence of the matrix (7)7.6.2 Influence of the RP material (8)8 Calculation and expression of results .............................................................................................. 8 8.1 Calculation of chromium(Vl) content ................................................................................................ 8 8.2 Recovery rate (according to 7.6.1) .................................................................................................... 9 8.3 Expression of results ......................................................................................................................... 9 9 Test report . (9)Annex A (informative) Reversed phase material (10)Annex B (informative) Accuracy (11)ww w .b z f x w .c o mForewordThis document (EN ISO 17075:2007) has been prepared by Technical Committee CEN/TC 289 "Leather", the secretariat of which is held by UNI, in collaboration with the International Union of Leather Technologists and Chemists Societies (IULTCS).This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2008, and conflicting national standards shall be withdrawn at the latest by May 2008.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS 14495:2003.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.Endorsement noticeThe text of ISO 17075:2007 has been approved by CEN as a EN ISO 17075:2007 without any modification.3EN ISO 17075:2007 (E)DIN EN ISO 17075:2008-02 :-w w w .b z f x w .c o m1 ScopeThis International Standard specifies a method for determining chromium(VI) in solutions leached from leather under defined conditions. The method described is suitable to quantify the chromium(VI) content in leathers down to 3 mg/kg.This document is applicable to all leather types.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2418, Leather — Chemical, physical and mechanical and fastness tests — Sampling locationISO 3696, Water for analytical laboratory use — Specification and test methodsISO 4044, Leather — Chemical tests — Preparation of chemical test samplesISO 4684, Leather — Chemical tests — Determination of volatile matter3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1chromium(VI) contentamount of chromium(VI) in leather determined by this method after extraction with an aqueous salt solution at pH 7,5 to 8,0NOTE The chromium(VI) content is reported as chromium(VI) in milligrams per kilogram (mg/kg), expressed as the dry mass of the sample.4 PrincipleSoluble chromium(VI) is leached from the sample in phosphate buffer at pH 7,5 to 8,0 and substances which influence the detection are removed by solid phase extraction if necessary. The chromium(VI) in solution oxidizes 1,5-diphenylcarbazide to 1,5-diphenylcarbazone to give a red/violet complex with chromium which can be quantified photometrically at 540 nm.The results obtained from the described method are strictly dependent on the extraction conditions. Results obtained by using other extraction procedures (extraction solution, pH, extraction time, etc.) are not comparable with the results produced by the procedure described in this standard.4 DIN EN ISO 17075:2008-02 EN ISO 17075:2007 (E)w w w .b z f x w .c o m5 ReagentsAll reagents used shall have at least analytical grade purity.5.1 Extraction solution .Dissolve 22,8 g dipotassiumhydrogenphosphate K 2HPO 4⋅3H 2O in 1 000 ml water, adjusted to pH 8,0 ± 0,1 with phosphoric acid (5.3). Degas this solution with either argon or nitrogen.5.2 Diphenylcarbazide solution .Dissolve 1,0 g 1,5-diphenylcarbazide CO(NHNHC 6H 5)2 in 100 ml acetone (CH 3)2CO and acidified with one drop of glacial acetic acid CH 3COOH.The solution should be kept in a brown glass bottle. The shelf life is up to 14 days at 4 °C.5.3 Phosphoric acid solution .700 ml o -phosphoric acid, ρ = 1,71 g/ml, made up to 1 000 ml with distilled water.5.4 Chromium(VI) stock solution .Dissolve 2,829 g potassium dichromate (K 2Cr 2O 7) (5.8) in water in a volumetric flask and make up to 1 000 ml with water. 1 ml of this solution contains 1 mg of chromium.5.5 Chromium(VI) standard solution .Pipette 1 ml of solution (5.4) into a 1 000 ml volumetric flask and make up to the mark with extraction solution (5.1). 1 ml of this solution contains 1 µg of chromium.5.6 Argon or nitrogen, oxygen-free .Preference should be given to argon as an inert gas instead of nitrogen because argon has a higher specific mass than air. 5.7 Distilled water , Grade 3 quality as specified in ISO 3696.5.8 Potassium dichromate (K 2Cr 2O 7), dried for 16 h ± 2 h at 102 °C ± 2 °C. 5.9 Methanol , HPLC grade. 6 Apparatus6.1 Suitable mechanical shaker , 50 min −1 to 150 min −1.6.2 Conical flask , of capacity 250 ml, with stopper.6.3 Aeration tube and flow meter .6.4 pH meter , with glass electrode.6.5 Membrane filter , 0,45 µm pore size (polytetrafluoroethylene or nylon).6.6 Volumetric flasks , of capacity 25 ml, 100 ml and 1 000 ml.6.7 Pipettes , various nominal volumes. 5EN ISO 17075:2007 (E)DIN EN ISO 17075:2008-02w w w.b z fx w .c o m6.8 Spectrophotometer or filterphotometer , wavelength 540 nm.6.9 Photometric cell , quartz, 4 cm length or any other suitable cell length.6.10 Glass or polypropylene cartridges filled with suitable reversed phase material , e.g. reversed phase (RP) 18.6.11 Solid Phase Extraction (SPE) system , with vacuum device or solvent resistant medical syringe. 7 Procedure7.1 Sampling and preparation of samplesIf possible, sample in accordance with ISO 2418 and grind leather in accordance with ISO 4044. Grinding should take place shortly prior to the extraction process. If sampling in accordance with ISO 2418 is not possible (e.g. leathers from finished products like shoes, garments), details about sampling shall be given together with the test report.7.2 Preparation of analytical solutionWeigh 2 g ± 0,01 g of ground leather to the nearest 0,001 g. Pipette 100 ml of degassed solution (5.1) into a 250 ml conical flask (6.2). Displace oxygen by passing oxygen-free argon (or nitrogen) (5.6) into the flask for 5 min (50 ml/min ± 10 ml/min). Remove the aeration tube (6.3), add the leather and close the flask with a stopper. Record the extract volume as V 0.Shake the leather powder suspension 3 h ± 5 min on a mechanical shaker to extract the chromium(VI).Gently shake the suspension in a smooth circular movement to keep the leather powder from adhering to the wall of the flask. Avoid shaking it too quickly. Immediately after completing 3 h of extraction, filter the content of the conical flask through a membrane filter into a glass bottle with screw cap. Check the pH of the solution. The pH of the solution shall be between 7,5 and 8,0. If the pH of the solution is not within this range, start the complete procedure again. 7.3 Determination of chromium (VI) in the solution obtained from the extraction procedure Pretreat the cartridges in the following way:a) flush the cartridge (6.10) first with 5 ml methanol (5.9),b) afterwards with 5 ml distilled water (5.7) andc) directly afterwards with 10 ml of extraction solution (5.1).Do not dry the cartridges (6.10) during or after the pre-treatment.From the solution obtained in 7.2, take 10 ml (V 1) and transfer this quantitatively through the cartridge (6.10) on an SPE system with vacuum device (6.11). Collect the eluate in a 25 ml volumetric flask (6.6). Flush the cartridge with 10 ml extraction solution (5.1) into the 25 ml flask. Make up the flask to volume (V 2) with extraction solution (5.1). Mark this solution as S 1.Pipette (6.7) 10 ml (V 3) of solution S 1 into a 25 ml volumetric flask. Dilute the solution to 3/4 of the flask’s volume with extraction solution (5.1). Add 0,5 ml of phosphoric acid solution (5.3) and afterwards 0,5 ml of diphenylcarbazide solution (5.2). Make up the flask to volume (V 4) with extraction solution (5.1) and mix well. Allow to stand for 15 min ± 5 min. Measure the absorbance of the solution at 540 nm in a 4 cm cell against the blank solution (7.4). Record the absorbance obtained as A 1.6 DIN EN ISO 17075:2008-02 EN ISO 17075:2007 (E)w w w .b z f x w .c o mFor each run, pipette another 10 ml aliquot of solution S 1 into a 25 ml volumetric flask and treat it as described above, but without the addition of the diphenylcarbazide solution (5.2). Measure the absorbance of this solution in the same way as before and record it as A 2.7.4 Blank solutionFill a 25 ml volumetric flask three quarters full with extraction solution (5.1), add 0,5 ml of phosphoric acid (5.3) and 0,5 ml of diphenylcarbazide solution (5.2) and make up to the mark with extraction solution (5.1) and mix well. Prepare this solution daily and store it in the dark. Treat the blank solution in the same way as the analytical solution, excluding the solid phase extraction.7.5 CalibrationPrepare calibrating solutions from the standard solution (5.5). The chromium concentration in these solutions should cover the expected range of measurements.Prepare the calibration solutions in 25 ml volumetric flasks (6.6).Plot a suitable calibration curve by using at least six standards, within the range 0,5 ml to 15 ml of standard solution (5.5). Pipette the given volumes of standard solution (5.5) into 25 ml volumetric flasks. Add 0,5 ml of phosphoric acid (5.3) and 0,5 ml diphenylcarbazide solution (5.2) to each flask. Make up to volume with extraction solution (5.1), mix well and allow to stand for 15 min ± 5 min. Measure the absorbance of the solutions in the same photometric cell as the samples at 540 nm against the blank obtained in 7.4.Plot the chromium(VI) concentrations in micrograms per millilitre (µg/ml) against the absorbance measured. Plot the chromium(VI) concentration on the x -axis and the absorbance on the y -axis.In interlaboratory tests, the 4 cm cell proved to be most suitable. The standard solutions described above are intended for analysis using a 4 cm cell. In some cases, however, it may be suitable to use higher or lower cell path length. Care shall be taken to ensure that the calibration range used is within the linear measuring range of the spectrophotometer. The measured extinction should not exceed 0,9 extinction units.7.6 Determination of the recovery rate7.6.1 Influence of the matrix The determination of the recovery rate is important to provide information about possible matrix effects which can influence the results. Spike a 10 ml aliquot of the solution obtained in 7.2 with a suitable volume of chromium(VI) solution to doubleapproximately the content of the chromium(VI) concentration of the extract (± 25 %). Select the concentration of the spiking solution in that way that the final volume of the spiked solution is maximum 11 ml. Treat this solution in the same way as the sample (recording the absorbance as A 1s and A 2s ). (See 7.3.)The absorbance of the solution shall be within the range of the calibration curve, otherwise repeat the procedure using a smaller aliquot. The recovery rate shall be greater than 80 %.NOTE 1 If the added chromium(VI) cannot be detected, this may be an indication that the leather contains reducing agents. In some cases, if the recovery rate according to 7.6.2 is greater than 90 %, and after intensive considerations, this may lead to the conclusion that this leather has no chromium(VI) content (below detection limit).NOTE 2 The recovery rate is an indicator of whether the procedure works or whether matrix effects are affecting the results. Normally, the recovery rate is greater then 80 %. 7EN ISO 17075:2007 (E)DIN EN ISO 17075:2008-02w w w .b z f x w .c o m7.6.2 Influence of the RP materialPipette a volume of solution (5.5) which corresponds to the chromium(VI) content of the leather into a 100 ml volumetric flask and make up to volume with extraction solution (5.1).Treat this solution in the same way as the leather extract. Determine the content in this solution in the same way as that of the leather extract and compare with the calculated content. In cases where no chromium(VI) was detected in the leather sample, the concentration of the solution shall be 6 µg/100 ml. The recovery rate shall be greater than 90 %. If the recovery rate is equal to or lower than 90 %, the RP material is not suitable for this procedure and shall be substituted.8 Calculation and expression of results8.1 Calculation of chromium(VI) content12024Cr(VI)13()A A V V V w V V m F−×××=××× where w Cr(VI) is the mass fraction, expressed in milligrams per kilogram (mg/kg), of soluble Cr(VI) in leather; A 1is the absorbance of sample solution with DPC; A 2is the absorbance of sample solution without DPC; Fis the gradient of calibration curve (y /x ), expressed in millilitres per microgram (ml/µg); mis the mass of the leather sample taken, expressed in grams (g); V 0is the extract volume of the initial sample, expressed in millilitres (ml); V 1is the aliquot taken from the extract volume of the initial sample, expressed in millilitres (ml); V 2is the total eluate (S 1) volume, after passage through the SPE column, to which the aliquot V 1 was made up, expressed in millilitres (ml);V 3is the aliquot taken from solution S 1, expressed in millilitres (ml); V 4 is the final make-up volume of the aliquot from S 1, expressed in millilitres (ml). Result based on dry matter:Cr(VI)-dry Cr(VI)w w D =×whereD is the factor for conversion to dry matter:100100D w=− w is the mass fraction of the volatile matter determined using ISO 4684, expressed as a percentage. 8 DIN EN ISO 17075:2008-02 EN ISO 17075:2007 (E)w w w .b z f x w .c o m8.2 Recovery rate (according to 7.6.1)()()1s 2s 12100A A A A F ηρ⎡⎤−−−⎣⎦=×× whereη is the recovery rate, expressed in percent (%); ρis the mass concentration of chromium(VI) spiked, expressed in micrograms per millilitre (µg/ml); Fis the gradient of calibration curve, expressed in millilitres per microgram (ml/µg);A 1s is the absorbance of solution after adding chromium(VI) and DPC;A 2s is the absorbance of solution after adding chromium(VI), but without adding DPC;A 1 is the absorbance of sample solution with DPC;A 2 is the absorbance of sample solution without DPC.8.3 Expression of resultsThe chromium(VI) content is given in milligrams per kilogram (mg/kg) rounded to the nearest 0,1 mg. The content is based on dry matter. The volatile matter (ISO 4684) is given in percent (%) rounded to the nearest 0,1 %.The extraction matrix for leather is complex (for example, due to coloration) and results below 3 mg/kg show large variation and have limited reliability, therefore the limit of detection should be considered 3 mg/kg.In the case of levels of chromium(VI) being detected above 3 mg/kg, the UV/VIS spectrum of the test solution should be compared with a standard solution (7.5) to determine whether the positive result is due to interfering substances.9 Test reportThe test report shall include the following information: a) the chromium(VI) content obtained from 8.1; b) a reference to this document (i.e. ISO 17075);c) a description of the sample tested and details about sampling (7.1), if necessary; d) the cell length used if not 4 cm;e) the results obtained to 1 decimal place in milligrams per kilogram (mg/kg);f)the volatile matter of the leather in percent (%);g) the recovery rate in percent (%) if lower than 80 % or higher than 105 %; h) details of any deviations from the procedure.ww w.bz fx w .co mAnnex A (informative)Reversed phase materialIn interlaboratory trials, cartridges with 1 g RP 18 material and DIONEX cartridges (Dionex OnGuard-RP, part number 39595) have been tested and found to be suitable. Other potential cartridges are supplied by WATERS (WATERS Sep-Pak Plus tC 18) 1). Nevertheless, in some cases it may be advisable to also use other phases or more than 1 g of SPE material. In any case, the recovery rate has to be tested very carefully. Charcoal proved to be unsuitable for the decolourization of the extracts.1) Dionex OnGuard-RP and WATERS Sep-Pak Plus tC 18 are examples of suitable products available commercially. Thisinformation is given for the convenience of the users of this document and does not constitute an endorsement by ISO of these products.ww w.bz fx w .co mAnnex B (informative)AccuracyResults obtained from two separate interlaboratory trials are illustrated in Tables B.1 and B.2 below.Table B.1 — Precision data from Trial 1 for two types of leathersValues in milligrams per kilogram (mg/kg)Chromium(VI) content a Repeatability b Reproducibility b7,04 1,58 3,22 7,83 1,11 3,54aMean values bP 95 %, factor 2,8Table B.2 — Results of Trial 2 for one type of leatherLaboratoryChromium(VI) contentmg/kgMean value mg/kg1001a 19,40 18,70 19,3 19,131002a 20,60 21,30 21,7 21,20 1006a 21,80 22,20 21,8 21,931007a 19,00 18,00 21,0 19,33 1008a 25,00 24,30 24,9 24,73 1009a 19,20 17,80 18,3 18,43 1010a 16,80 13,60 13,7 14,70501a 20,90 20,60 18,1 19,87 504a 22,00 20,00 19,00 20,33 505a 15,20 14,70 16,2 15,37 507a 24,10 23,40 25,7 24,40 508a 20,60 19,50 21,1 20,40 512a18,70 15,40 16,5 16,872892a 18,40 19,00 — 18,70 2893a 16,40 16,40 — 16,40 2894a 19,40 19,30 18,9 19,20Mean value: 19,4 mg/kgUncertainty:5,0 mg/kg.ww w .bz fx w.co mTaking into account the data displayed in Figure B.1, the limit of detection of the method is defined as 3 mg/kgfor the mean value.KeyX mean values of the interlaboratory tests (2003 to 2005) Y measurements uncertainties associated to the mean valueFigure B.1 — Graphical determination of the detection limit of the Cr(VI) test methodww w.bz。

皮革化学试验三氧化二铬含量的测定

皮革化学试验三氧化二铬含量的测定1适用范围适用于各种类型的皮革。

2 原理先将革样灰化，然后与氯酸钾混合在高温下熔融，三价铬被氧化为六价铬，过量的氯酸钾在高温下被分解。

再将溶液酸化，使六价铬与碘化钾作用而释出定量的碘，以硫代硫酸钠标准溶液滴定，即可计算出样品中三氧化二铬的含量，反应式如下：Cr2O3 +5KClO3→K2CrO4+ KCl +5O2+2Cl22KClO3 →2KCl+3O22K2CrO4+2HCl →K2Cr2O7+2NaCl+H2OK2Cr2O7+6KI+14HCl →2CrCl3+3I2+8KCl+7H2OI2 +2Na2S2O3 →2NaI+Na2S4O63 仪器及试剂3.1 瓷蒸发皿，100 mL；3.2电炉，1200W；3.3氯酸钾，C.P；3.4盐酸C.P，1:1溶液；3.5碘化钾溶液，10％；3.6硫代硫酸钠标准溶液：0.1mol/L。

配制和标定见4 分析步骤精确称取0.5g样品放在瓷蒸发皿中，于电炉上灰化完全后，冷却。

将氯酸钾粉末（约1g）均匀盖满灰化好的样品上，先用小火加热，慢慢转动蒸发皿，使之均匀熔化，待全部呈现黄色时，即用大火加热，至干涸为止。

将氧化好的样品冷却，全部转移至250 mL碘量瓶中，加入1:1盐酸溶液10 mL和10％碘化钾溶液10 mL ，塞上塞子，摇匀。

并用水封，在暗处放置10分钟，用0.1mol/L硫代硫酸钠标准溶液滴定，至溶液呈淡黄色时，加入淀粉指示剂（1～2）mL ，继续滴定至无色或淡绿色为终点。

纪录所耗硫代硫酸钠的毫升数。

5 计算皮革中三氧化二铬含量％按下式计算：Cr2O3（%）= c1V1×0.02533m×100% (1)式中：c1——硫代硫酸钠标准溶液的摩尔浓度，mol/L；V1——滴定消耗硫代硫酸钠标准溶液的体积，mL；m——样品的质量，g；0.02533——与0.001 mol/L硫代硫酸钠相当的以克表示的三氧化二铬的质量。

皮革污泥中铬的分析方法研究[开题报告]

毕业论文开题报告环境工程皮革污泥中铬的分析方法研究一、选题的背景、意义1.1 铬泥分析法的研究背景铬盐用于鞣制已经有百余年历史[1]。

至今，除了生产特殊用途的革以外，90%以上的制革厂都是采用铬鞣法主鞣。

因此，在铬鞣后的多次修边、削匀、磨革等机械加工过程，不可避免地会产生大量的铬革废弃物(也称铬革渣、铬革屑)。

其湿重约占蛋白类制革固体废弃物的50%，但干重(即蛋白质含量)约占70%以上，大量的铬革废弃物的处理问题在国内外一直是难题。

铬渣污染是迄今未能解决的世界环保难题[2-5]。

铬盐工业为无机化工与冶金材料交叉的重污染行业。

铬盐目前采用的传统高温焙烧-水浸-多级蒸发结晶工艺，资源能源利用率很低，铬转化率仅为75%，每吨铬盐产品要排放2～2.5吨高毒性铬渣，所含致癌性铬酸钙为国家排放标准的数倍。

因此，铬盐行业长期被列为我国严重污染行业之首，年排放高毒性铬渣30万吨及大量含铬粉尘废气，数百万吨积存废渣严重浸染地下水体，东北地区某厂曾造成1800吨水井报废的恶性事件，严重危及环境以及产业本身的生存发展。

我国是制革大国。

皮革产量约占世界的1/5—1/4，特别是制革工业主要使用的是片蓝皮工艺。

所以产生的铬革废弃物比例高、量多，据估算现在每年约产生70多万吨(湿重)的含铬废物。

据统计到2002年，我国皮革工业的出口创汇(100亿美元以上)虽然已经跃居轻工行业首位。

但是随之而来的环境污染问题也十分严重。

已成为制约我国皮革工业能否持续发展的重要因素。

因此，铬革废弃物的资源化与高值利用问题已经迫在眉睫。

20世纪90年代以来，随着全球性生态问题的日益严峻。

资源利用、环境保护、经济发展等多种社会动力的驱使和科技发展的需要，促使国内外皮革化学与工程及工业废渣处理领域的研究者，寻求铬革废弃物“高值利用”的途径及其潜在的市场应用。

特别是我国。

既缺乏不可再生资源“铬”。

又存在原料皮供应的缺口，当今，研究制革固体废弃物、特别是含铬固体废弃物的资源化和高值利用。

ICP-MS测定皮革中铅和铬含量59

电感耦合等离子体质谱测定皮革中铅和铬含量白子竹 ,韩军,杨阳,孙杰（北京市纺织纤维检验所，国家纺织及皮革产品质量监督检验中心，北京100024）摘要：建立了皮革试样用模拟人体酸性汗液充分萃取后，采用电感耦合等离子体质谱仪测定铅和铬两种元素的含量的测定方法。

关键词：电感耦合等离子体质谱;皮革;铅;铬Determination of Lead and Chrome in Leather by InductivelyCoupled Plasma Mass SpectrometerBAI Zi-zhu，HAN Jun，Y ANG Yang，SUN Jie(Beijing Textile Fiber Testing Institute, National Textile and Leather ProductQuality Supervision Testing Center, Beijing 100024, China)Abstract: The method to determinate the contents of lead and chrome in leather was established by Inductively Coupled Plasma Mass Spectrometer (ICP-MS), after the leather sample was extracted with acidic sweat.Keywords: Inductively Coupled Plasma Mass Spectrometer (ICP-MS) ; leather; lead ; chrome 引言我国是世界皮革和制鞋生产大国，同时也是原料皮资源大国、出口创汇大国、以及皮革制品的消费大国。

而传统的鞣制工艺及加工过程中使用的鞣剂、染料、助剂会使皮革及其制品中含有一定量的重金属元素，其中铅、铬等元素可通过汗液浸渍经皮肤侵入人体，严重危害人体健康。

原子捕获火焰原子吸收光谱测定皮革中的痕量铬

＊收穑日期：２０１０－０１—０２
作者简介：马亚军（１９７０－－），男．陕西省榆林市人，副教授，博士，研究方向：湿法分析及不对称合成与催化
万方数据
・６２・
陕西科技大学学报
第２８卷
定铬吸光度，根据标准工作曲线和稀释倍数求得样品中的铬含量．
１．２．２实验方法
分别准确移取一定量的Ｃｒ（ＶＩ）标准溶液于１５ｍＩ。离心管中，用５％硝酸定容至刻度，摇匀，调节石英双缝管至燃烧器火焰上方１０ＩＴｌｍ处，并使空心阴极灯光束刚好通过管中央。用ＦＡＡＳ测定其中Ｃｒ（ＶＩ）的含量．２结果与讨论
ｒｅａｃｔｉｏｎ［Ｊ］．Ｔａｌａｎｔａ，２００４．６３：９４１—９４７．
ＤＥＴＥＲＭＩＮＡＴＩｏＮ
ＣＨＲＯＭＥＩＮＬＥＡＴＨＥＲＢＹＦＬＡＭＥＡＴＯＭＩＣＡＢＳｏＲＰＴＩｏＮＳＰＥＣＴＲｏＭＥＴＲＹＵＳＩＮＧＡＴＯＭＴＲＡＰＰＩＮＧＴＥＣＨＮＩＱＵＥ
ＯＦＴＲＡＣＥ
ＭＡＹａ—Ｊｕｎ，ＷＡＮＧＲｕｉ—ｂｉｎ
液．按上述测定条件进行测定，图１中曲线ａ为常规的工作曲线，曲线ｂ为加单缝石英管后的工作曲线．由图１可知，铬的工作曲线ｂ的线性回归方程为Ａ＝０．７２１９ｚ＋０．０００６，Ｒ２—０．９９７７，线性范围为０．０６～
３６ｔ－ｔｇ／ｍＬ，检出限为０．０２ｔＬｇ／ｍＬ．
表２铬捕获前后灵敏度对比实验
摘
要：采用单缝式原子捕获石英管在火焰原子吸收光谱仪上测定皮革中的痕量铬，考察了捕
获时间、乙炔流量等测试条件的影响．实验表明，本方法的灵敏度比火焰原子吸收光谱法灵敏
度提高了４．５倍，相对标准偏差为１．５６％，加标回收率为９６．７％～１０３．０％，检出限可迭０．０２
ｔＬｇ／ｍＩ，，测定皮革中的痕量铬获得了满意的结果．关键词：皮革；铬；单缝石英管；原子捕获火焰原子吸收光谱（ＦＡＡＳ）中圈法分类号：０６５７．３１文献标识码：Ａ

皮革中Cr_6_的存在及检测

第12卷第2期皮　革　科　学　与　工　程 Vol 112,No 122002年4月L EATHER SCIENCE AND EN GIN EERIN G Apr 12002文章编号:1004-7964(2002)02-0022-06第一作者简介:刘卫国,男,1977年出生,硕士研究生收稿日期:2002-03-02皮革中Cr 6+的存在及检测刘卫国,张新申,蒋小萍(四川大学皮革化学与工程教育部重点实验室,四川　成都　610065)摘　要:扼要探讨了铬的两种化学形式Cr (Ⅲ)和Cr (Ⅵ)的主要化学性质,以及Cr (Ⅵ)在皮革中的形成原因,并讨论了皮革中Cr (Ⅵ)的提取和测定方法。

介绍并评价了一种新的Cr (Ⅵ)分析方法:流动注射分析法。

关键词:Cr (Ⅲ);Cr (Ⅵ);皮革;分析;流动注射分析;分光光度法中图分类号:TQ947 文献标识码:AForm ation and Determination of Chromium(VI)in LeatherL IU Wei -guo ,ZHA N G Xi n -shen ,J IA N G Xiao -pi ng(The Key Laboratory of Leather Chemistry and Engineering of Ministry ofEducation ,Sichuan University ,Chengdu 610065China )Abstract :Chromium (V I )is highly toxic and serves no biological purpose.The properties of Chromium (Ⅲ)and chromium (V I )are introduced.The formation and determination of Chromium (V I )in leather are reviewed.Moreover ,a new method ,flow injection analysis ,was also introduced or the purpose to determinate chromium (V I )in leather.K ey w ords :Chromium (Ⅲ);Chromium (V I );leather ;determination ;flow injection analysis ;1　引言由于其优异的鞣革性能,铬被大量应用于鞣制过程中。

皮革中六价铬含量检测标准ISO 17075更新

工业出版社．２００７．
补偿办法．但还是不能使环境温度的影响得到完全的补偿，因此规定了这类压力式温度计使用时的环境温度变化范围，实际使用时要注意这个问题。（５）不宜测量接近室温的温度。因为被测温度在室温附近波动，毛细管和弹簧管内的蒸气一会儿汽化，一
电阻安装于测温元件内，实现了机电一体化的测温功能，形成了以液体压力式温度计为基本测温仪表的防
震、防腐、电接点、温度信号变送等多功能系列化温度仪表。小型压力式温度计可用于汽车、拖拉机、润滑油系统、内燃机冷却水系统的温度测量，还可以远距离传输测量数据，且不需要电源，使用中不会产生火花，故具有防爆性，可以用来测量易燃易爆物品等。参考文献：［１】王槐汉．温度测量实用技术［Ｍ］．北京：机械
４结束语
压力时，那么就应该使用带有）要合理的选择压力式温度计的测温范围。对于液体压力式温度计来讲，最好用它测量处于其测温范围中间部分的介质的温度；而蒸气压力式温度计，最好用
以减少导热误差，并且保持一定时间，待示值稳定后再读数。（２）在使用压力式温度计的过程中，要充分了解被测介质的情况，如果发现被测介质有腐蚀作用或有较高

oeko皮革六价铬测试方法

oeko皮革六价铬测试方法
以下是Oeko-Tex Standard 100认证中六价铬的测试方法：
1. 试样准备：取一定量的皮革样品，将其切碎后称重，并放入250mL碘量瓶中。

2. 缓冲溶液配制：加入100mL K2HPO4缓冲溶液，充氮气后盖紧塞子振荡3小时，过滤。

滤液pH值应控制在之间。

3. 显色剂和磷酸溶液的配制：取滤液10mL于50mL容量瓶中，加水到
40mL，然后加入1mL显色剂和1mL磷酸溶液，加水到刻度，混匀。

同时作试剂空白（不加滤液）和试样空白（不加显色剂）试验，以试剂空白试验作参比。

4. 吸光度测定：在15min后（±5min）于542nm处测定空白试样和样品显色后的吸光度。

5. 工作曲线的绘制：取铬标准液各0,,,,,,,于50mL容量瓶中，按步骤3中的同样操作测定铬标准液的吸光度，以铬μg/50mL为横坐标，得到吸光度—铬μg/50mL工作曲线。

6. 结果计算：根据样品显色后的吸光度和工作曲线，计算样品中六价铬的含量。

以上是Oeko-Tex Standard 100认证中六价铬的测试方法，仅供参考。

在实际操作中，需要根据具体情况进行调整和优化。

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指导教师签字年月日
备注：此任务书由指导教师填写，并于毕业设计（论文）开始前下达给学生。
重庆三峡学院
毕业设计（论文）任务书
题目分光光度法测定皮革中铬的方法探究
姓名学院化学与环境工程专业化学工程与工艺年级班别
指导教师职称下达任务日期2013年12月8日
主要研究内容、方法和要求
主要内容：
1.对铬对人体的危害进行了解。
2.对于目前对皮革中铬含量的检测方法进行了解。
3.对测方法进行对比选择，同时尝试自己设计检测方案，为后续的设计实验做准备。
[2]俞从正,孙根行,郭生伟.皮革中六价铬成因初探[J].中国皮革,2002,(第3期).
[3]秦涛,田磊,刘绍，等.皮革中六价铬的测定研究进展[J].皮革与化工,2010,(第1期).
[4]沈兵，王练，奚奇辉.高效液相色谱法测定皮革中的六价铬[J].中国皮革，2008,37（11）：39-41.
[5] ISO5398-3-2007.皮革.氧化铬含量的化学测定.第3部分：原子吸收光谱测定法定量测定[S].
研方法与要求：
1.查阅与课题相关的资料，并记录为后续论文的撰写做准备。
2.对于了解到的检测方法进行思考，看是否有可改进的地方。
3.选定的方案应可快速，较精确，且成本低廉的检测皮革中的铬含量。
4.可以提高大量检测的效率，为精确的测量做筛选。
进度计划
2013年12月前查阅资料、文献、准备开题
2013年12月撰写开题报告，提交开题报告
2014年3月中上旬进行资料整理，准备撰写论文
2014年4月中上旬提交论文第一稿，根据指导老师的意见，认真修改
2014年4月中旬提交论文第二稿，根据指导老师的意见，认真修改
2014年5月上旬提交论文第三稿，定稿
2014年5月中下旬准备论文答辩
主要参考文献
[1]周玉敏主编.分析化学2版[M].北京市：化学工业出版社, 2009.