【商检行业标准(SN)】 出口皮革及皮革制品中五氯酚残留量检验方法 乙酰化-气相色谱法

中华人民共和国进出口商品检验行业标准SN0193.1-93
上商中务
i2括9.4324
出口皮革及皮革制品中五氯酚
残留量检验方法
乙酰化气相色谱法
Method for determination of pentachlorophenolresidues in leather and leather products for exportAcetylation-gaschromatography1993-06-04发布
中华人民共和国国家进出口商品检验局1993-08-01实施
（京）新登字023号
中华人民共和国进出口商品检验行业标准出口皮革及皮革制品中五氯酚
残留量检验方法乙酰化-气相色谱法Method for determination of pentachlorophenolresidues in leather and leather products for exportAcetylation-gaschromatography1主题内容与适用范围
SN 0193.1-93
本标准规定了出口皮革及皮革制品中五氯酚残留量检验的抽样、制样和气相色谱测定方法。本标准适用于出口皮革及皮革制品中五氮酚残留量的检验。抽样和制样
出口皮革及皮革制品中五氮酚残留量的检验样品可取自于原料皮革。2.1检验批
以不超过1万件为一检验批。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
抽样件数可按式(1)计算：
元=0.5/N
式中：n—抽样件数；
N一每个检验批内的总件数。
取样件数不得少于3件，每一检验批内取样总量不得少于500g。2.3抽样工具
割刀，剪刀。
2.4抽样方法
（1）
在检验批中抽取样品时，先数清整批革的数量，而后顺次每隔N/n件取一件，割下或剪下部分作为原始样品。同一取样单位的原始样品放在同一塑料袋或容器内，加封后，标明标记，并及时送实验室。2.5试样制备
将皮革样品剪成约1cm见方的小块，混和并以四分法缩分出50g以上样品，于食品粉碎机中粉碎，使全部通过2mm直径孔筛，制成均匀样品。制备好的试样盛于500mL广口具磨口塞样品瓶中。2.6试样保存
试样于室温下保存。
注：在抽样和制样的操作过程中，必须防止样品受到污染或发生残留物含量的变化。3测定方法
3.1方法提要
中华人民共和国国家进出口商品检验局1993-06-04批准1993-08-01实施
SN 0193.1-—93
样品中残留的五氯酚及其钠盐在硫酸溶液中均成五氮酚，用正已烷提取。经浓硫酸净化后，再以四硼酸钠水溶液反提取。加入乙酸酐生成五氯酚乙酯，最后以正已烷提取。用配有电子俘获检测器的气相色谱仪检测，以艾氏剂作内标进行定量，3.2试剂和材料
除特殊规定外试剂均为分析纯，水为蒸馏水或相适应的去离子水。3.2.1浓硫酸。
硫酸溶液：6:mol/L。
四硼酸钠溶液：0.1mol/L。
正已烷：全玻璃仪器加碱重新蒸馏。无水硫酸钠：经650℃4h灼烧。
：无水硫酸钠柱：类似筒形漏斗的柱，内装5cm高的无水硫酸钠。3.2.7
乙酸酐。
内标及五氯酚标准品：纯度>99%。3.2.9内标及五氯酚标准溶液的配制3.2.9.1内标溶液配制：称取0.05g艾氏剂，精确至0.0001g，于100mL容量瓶中，用正已烷溶解并定容，再用正已烷定量稀释至浓度为0.500μg/mL。3.2.9.2五氯酚标准溶液的配制：称取0.10000g五氯酚标准品，精确至0.1mg，于100mL容量瓶中，用正己烷溶解并定容作为贮备液，五氮酚浓度为1.000mg/mL。定量稀释，并移取一定量稀释液按测定步骤3.4.3乙酰化后制成标准工作液（使五氯酚浓度与样液中被测组分浓度相近，内标物艾氏剂浓度约为0.0500μg/mL）。
3.3仪器和设备
3.3.1气相色谱仪并配备电子俘获检测器。3.3.2积分仪或记录仪。
3.3.3食品粉碎机。
3.3.4离心机。
3.3.5混合器。
3.3.6.微量注射器：10μL。
3.4测定步骤
3.4.1提取
称取试样约1.0g（精确至0.01g）于50mL离心管中，加20mL6mol/L硫酸，在混合器上混匀2min。加入20mL正已烷，振摇3min后在混合器上混匀2min，并在3000r/min下离心2min。用吸管吸取正已烷层移入另一50mL离心管中，残液再用10mL正已烷重复提取一次，合并正已烷提取液在同一离心管内。
3.4.2净化
在正已烷提取液内徐徐加入10mL浓硫酸，振摇0.5min，在3000r/min下离心2min。用吸管将正已烷提取液移入·125mL分液漏斗中，再用2mL正已烷冲洗离心管管壁，静置分层后，用吸管将正已烷冲洗液合并于同一分液漏斗中。弃去硫酸层。在上述正已烷中加30mL0.1mol/L四硼酸钠溶液，振摇1min，静置分层。.将下层水相放入另125mL分液漏斗中。正已烷层再以20mL0.1mol/L四硼酸钠溶液提取一次，合并下层水相于同一分液漏斗。弃去正己烷层。
3.4.3乙酰化
在上述四硼酸钠水溶液中加入0.5mL乙酸酐，振摇1min，再加入10mL正已烷，振摇1min，静置分层。弃去下层水相。于正已烷溶液中，再每次用20mL0.1mol/L四硼酸钠水溶液洗涤正已烷层，共2
SN 0193.1-93
二次，振摇，静止分层，弃去水层。从分液漏斗上口将正已烷层经无水硫酸钠柱脱水后收集于具塞10mL试管内，定量地加入适量内标溶液（一般为0.5ug艾氏剂），此溶液供气相色谱测定。3.4.4测定
3.4..4.1色谱条件
a.色谱柱：玻璃柱，2m×3mm（内径），填充物为1.6%（m/m）0V-17+6.4%（m/m）0V-210涂于ChromosorbWHP(80~100目）；氮气：纯度≥99.99%，80mL/min；b.
柱温：210℃；
进样口温度：250℃；
检测器温度：250℃。
3.4.4.2色谱测定
分别将标准工作溶液、样液注入气相色谱仪，进样量各5μL。标准工作溶液中被测组分的浓度应与样液相近。出峰保留时间：五氮酚乙酯约为3.3min；艾氏剂约为5.6min。3.4.5空白试验：除不加试样外，按上述测定步骤进行。3.4.6结果的计算和表述
用色谱数据处理机按内标法计算或按式(2)计算：C·A·A..
Ci.A·A..
式中：X-
一试样中五氮酚含量，mg/kg；
标准工作液中五氯酚乙酯(以五氯酚计)浓度，μg/mL；标准工作液中艾氏剂浓度，μg/mL；一样液中五氟酚乙酯色谱峰面积，mm2；A-
样液中艾氏剂色谱峰面积，mm2；-标准工作液中五氯酚乙酯色谱峰面积，mm2；-标准工作液中艾氏剂色谱蜂面积，mm2；样液中艾氏剂总量，ug；
一试样总量，g。
注：计算结果须扣除空白值。
4测定低限、回收率
4.1测定低限
本方法的测定低限为0.1mg/kg。4.2回收率
回收率实验数据：五氯酚浓度在0.102～18.1mg/kg范围内，回收率为92.9%101.7%。附加说明
本标准由中华人民共和国国家进出口商品检验局提出。本标准由中华人民共和国上海进出口商品检验局负责起草。本标准主要起草人葛修丽。
参考文献：
Determinationof Pentachlorophenol inAnimal Tissues,JAOAC73,838—--8411990.Professional Standard of the People's Republic of Chinafor Import and Export Commodity InspectionMethod for determination of pentachlorophenolresidues in leather and leather products for export-Acetylation-gas chromatography1'Scopeand field of applicationSN 0193.1-93
This standard specifies the method of sampling, sa'mple preparation and determination of pen-tachlorophenol residues by gas chromatography in leather and leather products for export.This standard is applicable to the determination of pentachlorophenol residues in leather andleather products for export.2Sampling and samplepreparationThe sample for determination of pentachlorophenol residue in leather and leather products for ex-portmaybetakenfromleatherrawmaterials2.1 Inspection lot
The quantity of an inspection lot should not be more than lo ooo pieces.The characteristics of the cargo within.the same inspection lot,such as packing,mark,origin.specification,grade etc.,should be the same.2.2 Quantity of sample takenThe number of pieces taken may be calculated according toformula (1):n=0.5N
n--number of pieces taken;
N-total number of pieces within one inspection lot.The number of pieces taken should be not less than 3,and the sample taken from each inspectionlot should be not less than 500 g.2.3. Sampling tools
Bark hack and scissors.
2.4 Sampling procedure
When sample is taken from the inspection lot ,count the number of pieces of the whole lot at first,then successively take one piece from every N/n pieces and cut or clip part of it as primary sample. Putthe primary samples of the same lot into the same plastic bag or container,seal and label and send tothe laboratory in time.
2.5Preparation-of test sampleApproved bythe State AdministrationofImportandExportCommodityInspectionofthe People's Republic of China on Jun.4,1993Implemented from Aug.1,1993
SN 0193.1-93
Clip the sample into small pieces of ca 1 cm,mix and reduce the pieces to not less than 50 g byquartering. Then grind the sample with a food mill and pass through the sieve of 2 mm diameter aper-tures to form a uniform sample. The prepared sample is put into a 500 mL widemouth sample bottlewith a ground glass stopper.2.6 Storage of sample
Thetestsampleis storedatroomtemperatureNote: In the course of sampling and'sample preparation,precaution must be taken to avoid contamination or anyfactors which may cause the change of residue content.3Method of determination
3.1Principle
The pentachlorophenol and its sodium salt residues in the sample will all turn to pen-tachlorophenol in sulphuric acid solution,which is then extracted with n-hexane. After cleaned up byconcentrated sulphuric acid,extract with sodium tetraborate solution. Acetylate with acetic anhydrideand finally extract with n-hexane. Determination is made by gas chromatorgraph with electron capturedetector. Aidrin is used as internal standard for quantitative measurement.3.2 Reagents and materials
Unless otherwise specified,all reagents should be of analytical grade,\water\ is distilled water orcorresponding de-ionized water.3.2.1Concentrated sulphuric acid..3.2.2Sulphuric acid solution:6mol/L3.2.3 Sodium tetraborate solution':0.1 mol/L.3.2.4n-Hexane:Redistilled with alkali by glass apparatus.3.2.5Anhydrous sodium sulfate:Ignite at 650C for 4h.3.2.6 Column of anhydrous sodium sulfate:A 6 cm X18 mm(id) glass column,filled with 2.5 cmheight of anhydrous sodium sulfate.3.2.7 Acetic anhydride.
3.2.8Internal standard and.pentachlorophenol standard:Purity>99%.3.2.9 Preparation of internal standard and pentachlorophenol standard solution.3. 2. 9. 1 - Internal standard solution : Weigh 0. 05 g of pure aldrin,accurate to 0. 000 1 g ,into a 100 mL.volumetric flask,add n-hexane to dissolve it and dilute to volume. Further dilute this solution to a concentration of 0.500 μg/mL.
3. 2. 9. 2 Pentachlorophenol standard solution: Weigh 0. 100 00 g of standard pentachlorophenol (ac-curate to 0. 1 mg)into a 100 mL volumetric flask. Add n-hexane to dissolve it and dilute to volume asthe standard stock solution with a concentration of 1. 0o0 'mg/mL. Dilute-quantitatively and transfercertain amount of the solution and prepare the standard working solution after acetylation according tothe procedure in 3. 4. 3(with a pentachlorophenol concentration closing to that of the sample'solutionand aldrin concentration as internal standard being ca 0. 050 0 μg/mL).3.3Apparatusandequipment
3. 3. 1 Gas chromatograph with electron capture detector.3.3.2 Integrator or recorder.3.3.3Food mill.
Centrifuge.
3.3.5Mixer.
3.3.6 Micro-syringe:10 μL.
3.4Procedure
3.4.1 Extraction
SN 0193.1--93
Weigh ca 1. 0 g of the sample (accurate to 0. 001 g) into a 50 mL centrifuge tube. Add 20 mL of 6mol/L suphuric acid and mix thoroughly on the mixer for 2 min.Add 20 mL of n-hexane,shake for 3min and mix thoroughly on the mixer for another 2 min. Centrifugalize at 3 ooo r/min for 2 min.Transfer the n-hexane layer with a pipette into a second 5o mL centrifuge tube.Re-extract the remain-ing solution with 1o mL of n-hexane and combine the n-hexane extract with that in the second cen-trifuge tube.
3.4.2 Clean up
Add 1o mL of concentrated sulphuric acid to n-hexane extract and shake for o. 5 min,then cen-trifugalize at 3 000 r/min for 2 min. Transfer the n-hexane extract into a 125 mL separatory funnelwith a pipette. Add 2 mL of n-hexane to rinse the centrifuge tube wall,and let stand to separate. Com-bine the n-hexane rinse solution in the separatory funnel with a pipette. Discard the sulphuric acid lay-er
Add slowly 3o mL of o.1 mol/L sodium tetraborate solution to.the above n-hexane soiution,shake for 1 min and let stand to separate. Transfer the lower aqueous layer into another 125 mL sepa-ratory funnel,the n-hexane layer is then extracted once more with 20 mL of o. 1 mol/L.sodium tetrab-orate solution. Combine'the lower aqueous layers in the same separatory funnel. Discard the n-hexanelayer
3.4.3Acetylation
Add o.5 mL of acetic anhydride to the above sodium tetraborate solution and shake for 1 min,then add 1o mL of n-hexane and shake for 1 min. Let stand to separate. Discard the lower aqueous lay-er. Wash it twice,each with 2o mL of o.1 mol/L sodium tetraborate solution.Shake and let stand toseparate. Discard the aqueous washings. From the upper mouth of the separatory funnel pass the n-hexane layer through an anhydrous sodium sulfate column to remove the water and collect the effluentin a lo mL test tube with a stopper. Add adequate internal standard solution quantitatively (generally0.5 μg for aldrin) to the n-hexane layer.The sample solution is thus.ready for GC determination3.4.4Determination
3.4.4.1 Gas chromatographic operating conditionsGCColumn:Glass,2m×3mm(id),packedwith1.6%(m/m)OV-17+6.4%(m/m)OVa.
210onchromosorbWHP(80—100mesh);b.Nitrogen:Purity≥99.99%,80mL/min;c.
Column temperature:210C;
d.Injection port temperature:25o ℃;e.
Detector temperature:250 C.
-3.4.4.2GCdetermination
Inject separately the standard working solution and sample solution into the gas chromatographInjection'volume: 5 μL each. The concentration of the constituent to be determined in the standardworking solution should be close to that of the sample solution. Retention time: ethyl pen-tachlorophenolate:ca3.3min;aldrin:ca5.6minunder aboveGC condition.3.4.5Blank test
SN0193.1-93
The operation of the blank test is the same as that described in the method of determination butwith omission of sample addition.3.4.6 Calculation and expression of the resultCalculate the content of pentachlorophenol in the sample by GC data processor or according toformula (2)：
X=S:A·Ag-m
Csi·A·A,·m免费标准下载网bzxz
（2）
X--Content of pentachlorophenol in the test sample,mg/kg;C,—Concentration of ethyl pentachlorophenolate (calculated as pentachlorophenol) in the stan-dard working solution,μg/mL;Csi-Concentration of aldrin in the standard working solution, μg/mL;A--Peak area of ethyl pentachlorophenolate in the sample solution,mm’;A,--Peak area of aldrin in the sample solution,mm;A.-Peak area of ethyl pentachlorophenolate in the standard working solution,mmA..Peak area of aldrin in the standard working solution,mm°;m:Total mass of aldrin in the sample solution,μg;m--Total mass of sample,g.
Note: The blank value should be subtracted from the result of calculation.4 Limit of determination and recovery4.1 Limit of determination
The limit of deternination of this method is 0.1 mg/kg4.2Recovery
According to the experimental data,when the concentration of pentachlorophenol is in the rangeof0.102-18.1mg/kg，therecoveryis92.9%—101.7%.Additional explanation :
This standard was proposed by the State Administration of Import and Export Commodity In-spection of the People's Republic of China.This standard was drafted by Shanghai Import and Export Commodity Inspection Bureau of thePeople's Republic of China.
This standard was mainly drafted by Ge Xiuli.Reference:
Determination ofPentachlorophenoi in Animal Tissues,JAOAC 73,838--841,1990.Note:This English versiona translation from the Chinese textis solely forguidance.SNO19
中国标准出版社出版
中国标准出版社北京印刷厂印刷1993年11月第一次印刷
1993年11月第一版
书号：155066·2-9086
61610
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