1、中华人民共和国出入境检验检疫行业标准SN/T 1594-2005 进出口茶叶中喔曝酬残留量检验方法气相色谱法Inspection of buprofezin residue in tea for import and export Gas chromatographic method 2005-05-20发布2005-12-01实施中华人民共和国发布国家质量监督检验检疫总局前言本标准的附录A为资料性附录。本标准由国家认证认可监督管理委员会提出并归口。本标准起草单位:中华人民共和国浙江出入境检验检疫局。本标准主要起草人:丁慧瑛、朱晓雨、谢文、章晓氧、朱青青。本标准系首次发布的出入境检验检疫行业标
2、准。SN/T 1594-2005 I SN/T 1594-2005 1 范围进出口茶叶中曝嗦嗣残留量检验方法气相色谱法本标准规定了进出口茶叶中唾嗦酣残留量检验的抽样、制样和气相色谱测定方法。本标准适用于进出口茶叶中唾嗦酣残留量的检验。2 抽样和制样2. 1 检验批以不超过2000件为一检验批。同一检验批的商品应具有同一特征，如包装、标记、产地、规格、等级等。2.2 抽样数量抽样数量见表1。表1抽样数量单位为件批量最低抽样数15 l 650 2 51500 11 5011 000 16 1 0011 500 19 1 5012 000 20 2.3 抽样方法按2.2规定的抽样件数随机抽取，逐件开
3、启。每件中最少取500g作为原始样品。将所抽原始样品充分拌匀(或用分样器分取)缩分出500gl 000 g，装入清洁密封的样品筒内，加封后，标明标记，及时送交实验室。2.4 试样制备将所取全部样品磨碎，通过孔径为0.85mm筛(20目)，均分成两份，装入洁净的容器内，作为试样。密封，并标明标记。2.5 试样保存在抽样和制样的操作过程中，应防止样品污染或发生残留物含量的变化。试样应于室温下保存。3 测定方法3. 1 方法提要样品中的唾嚓酣残留用丙嗣和水提取，再经正己烧反萃取，弗罗里硅土柱净化。用配有氮磷检测器的气相色谱仪测定，外标法定量。3.2 试剂和材料除另有规定外，所用试剂均为分析纯，水为蒸
4、锢水。3.2.1 乙醋。SN/T 1594-2005 3.2.2 正己烧。3.2.3 丙酬。3.2.4 氯化铀水榕液150g/L。3.2.5 洗脱液:正己皖-乙醋。十3)。3.2.6 无水硫酸饷:6500C灼烧4h，在干燥器内冷却至室温，贮于密封瓶中备用。3.2.7 弗罗里硅土:粒度O.075 mmO. 15 mm(lOO目200目)0 6500C灼烧4h，使用前一天于1300C活化4h，在于燥器内冷却至室温，加1%的水脱活，备用。3.2.8 脱脂棉。3.2.9 唾嚓酣标准品:纯度大于99%。3.2. 10 唾嗦酣标准储备榕液z称取0.01000g唾嗦酣标准品(3.2.9)，用正己烧溶解定容至
5、100mL , 此溶液浓度为100g/mL。存放在40C的冰箱中。根据需要用正己皖稀释至适当浓度的标准工作液。3.3 仪器和设备3.3. 1 气相色谱仪，配有氮磷检测器。3.3.2 旋转蒸发器。3.3.3 均质器。3.3.4 无水硫酸铀柱:80mmX40 mm(内径)筒型漏斗，底部垫约5mm高脱脂棉，再装约50mm高无水硫酸铀。3.3.5 净化柱:200mmX15 mm(内径)玻璃柱，底部垫约5mm高脱脂棉和约20mm高无水硫酸锅，10 g弗罗里硅土，顶端加约20mm高无水硫酸铀，使用前用30mL正己皖淋洗。3.4 测定步骤3.4. 1 提取称取5g试样(精确到0.01g)置于100mL烧杯中
6、，加入15mL蒸馆水浸泡2h，加入30mL丙酬，在均质器中均质2min。过谑至50mL容量瓶中，用丙酬清洗残渣，合并滤液，并定容至50mL。移取20.0 mL捕、液至预先装有50mL氧化铀水榕液(3.2.4)和25mL正己烧的250mL分液漏斗中，剧烈振摇，静置分层。水相中再加入25mL正己烧，重复操作，合并正己烧相，过无水硫酸铀柱(3.3.4)至浓缩瓶中，用旋转蒸发器在450C水浴减压浓缩至近干。3.4.2 净化浓缩瓶中残留物用2mL、2mL正己烧溶解洗涤2次，将溶液移入净化柱中(3.3.5)，用100mL洗脱液(3.2.5)搅脱。收集全部洗脱液，用旋转蒸发器在450C水陆减压浓缩至近干，加
7、入2.0mL正己皖溶解，供气相色谱测定。3.4.3 测定3.4.3. 1 色谱条件进行测定色谱条件如下:a) 色谱柱z石英毛细管柱，HP-Ultra225 mXO. 32 mm(直径)X 0.52m(膜厚)，固定相为:(5%)二苯基-(95%)二甲基硅氧皖共聚物，或相当者;b) 载气和尾吹气:氮气(纯度大于99.999%)，载气流量:5.0 mL/min，尾吹气流量:20 mL/min , 空气流量:110 mL/min;氢气流量:3.5mL/min; c) 柱温:初始温度700C保持1min，以250C/min升至2800C，保持8min; d) 进样口温度:250oC;e) 检测器温度:3
8、00oC;f) 开阀时间:1min; g) 进样方式t不分流进样;h) 进样量:2L;2 SN/T 1594-2005 i) 制盐珠的电压应调整至最佳状态。3.4.3.2 色谱测定根据样液中唾嗦酣含量的情况，选定峰面积相近的标准工作溶液。标准工作榕液和样液中唾嗦酣的响应值应在仪器检测的线性范围内。标准工作榕液和样液等体积穿插进样测定。在上述色谱条件下，唾嗦酣的保留时间约为12.3mino唾嗦酣标准品的气相色谱图参见附录A中图A.1。3.4.3.3 空白试验除不加试样外，均按上述操作步骤进行。3.4.3.4 结果计算和表述计算结果需扣除空白值，用色谱数据处理机或按式(1)计算试样中唾嗦酬的残留含
9、量:V一一目c一-s -A A-X . ( 1 ) 式中:X一一一试样中唾嗦酣的残留量，单位为毫克每千克(mg/kg); A一一样液中唾嗦酣的峰面积，单位为平方毫米(m2); A，标准工作液中唾嗦酬的峰面积，单位为平方毫米(m2); c一一标准工作液唾嗦酣的浓度.单位为微克每千克(g/mU;V 样液最终定容体积，单位为毫升(mL); m 最终样液所代表的试样质量，单位为克(g)。4 测定低限和回收率4. 1 测定低限本方法的测定低限为0.01mg/峙。4.2 回收率唾嗦酣添加浓度在0.01mg/kg时，回收率为82%100%; 唾嗦酣添加浓度在0.02mg/kg时，回收率为80%100%; 唾
10、嗦酣添加浓度在0.2mg/同时，回收率为85%100%。3 SN/T 1594-2005 4 附录A(资料性附录)标准晶色谐圄唾嚓嗣上飞罐. 圄A.1唾曝酣标准晶气相色i曾固. tR/min SN/T 1594-2005 Foreword Annex A of this standard is an informative annex. This standard was proposed by and is under the charged of The Certification and Accreditation Ad ministration of the Peoples Repub
11、lic of China. This standard was drafted by Zhejiang Entry-Exit Inspection and Ouarantine Bureau. The standard was mainly drafted by Ding Huiying. Zhu Xiao yu. Xie Wen. Zhang Xiao Dong and Zhu Oing Oing. This standard is a professional standard for entry-exit inspection and quarantine promulgated for
12、 the first time. 5 SN/T 1594-2005 Inspection of buprofezin residue in tea for export and import -Gas chromatographic method 1 Scope This standard specifies the methods of sampling , sample reparation and determination bgas chro matography(GC) of buprofezin residue in tea for export and import This s
13、tandard is applicable to the determination of buprofezin residues in tea for export and import Sampling and sample preparation. 2 Sampling and sample preparation 2. 1 Inspection lot Each inspection lot should not be exceed 2 000 packages. The characteristics of the cargo within the same inspection l
14、ot , such as packing , mark, origin ,speci fication and grade etc. should be the same. 2. 2 Quantity of sample taken Quantity of sample taken(see Table 1. Number of packages in an inspection lot 1-5 6-50 51-500 501-1 000 1 001-1 500 1 501-2000 2. 3 Sampling procedure Table 1 Minimum number of packag
15、es to be taken 2 11 16 19 20 Draw a number of packages specified in 2. 2 are taken at random and open the packages. The least sample weight as the primary sample from each package should be at 500 g. The combine primary sample is fully mixed , reduced to 500一1000g, placed in a clean sample canister
16、, sealed , labeled and sent to laboratory in time. 2. 4 Preparation of test sample The mixed primary sample is crushed with a grinder or mortar until throughly crushed and wholly 6 SN/T 1594-2005 passed through a O. 85 mm(id) sieve (20 mesh) , and then divided into two equal portions. Each por tion
17、is placed in a clean container as the test samp怡，which is then sealed and labeled. 2. 5 Storage of test sample In the course of sampling and sample preparation , precautions must be taken to avoid contamination or any factors which macause the change of residue content. The test samples should be st
18、ored at room temperature, 3 Method of determination 3. 1 Principle Buprofezin residue are extracted from the tea sample by acetone, and re-extracted by hexane , and cleaned up by passing through a florisil column. The solution is used for GC-NPD determination. Ex ternal standard method is used for q
19、uantitative measurement. 3. 2 Reagents and materials Unless otherwise specified , all the reagent used should be analytical. grade , water is distilled wa ter. 3. 2. 1 ethyl ether. 3. 2. 2 n-hexane. 3. 2. 3 acetone. 3.2.4 Sodium chloride solution 150 9 /L. 3.2.5 Eluting solution: n-hexane-ethyl ethe
20、r(7 + 3). 3.2.6 Anhydrous sodium sulfate: ignite for 4 h at 6500C , and keep in a tightly closed container. 3.2.7 Florisil: granule size O. 075 mm-O. 15 mm (100 mesh-200 mesh) , ignite for 4 h at 6500C , and keep in a tightly closed container, then heat for 4 h at 130C in an oven , cooling to room t
21、emper ature in desiccator and add 1 % of water before use. 3. 2. 8 Absorbent cotton. 3.2.9 Satandard of buprofezin: purity99%. 3.2.10 Stock satandard solution of buprofezin: accurately weight 0.010 00 9 Satandard(3. 2.酌，dissolve with n-hexane and quantitatively on 100 mL, the concentration of soluti
22、on is 100g/mL. he solution shall be stored in 40C refrigeratory. According to the requirement , is prepared from the 7 SN/T 1594-2005 stock standard sofution by n-hexane and difuted to the required concentration. 3.3 Apparatus and equipment 3.3. 1 Gas chromatography, equipped wth Ntrogen phosphorus
23、detector. 3. 3. 2 Rotary vacuum evaporator 3.3.3 Hgh speed blender. 3.3.4 Column of anhydrous sodium sulfate: 80 mm x 40 mm(id) cylinder funnel , pack with ca 5 mm absorbent cotton at the bottom of the column and fll n 50 mm anhydrous sodum sulfate. 3.3.5 Column for clean-up: 200 mm x 15 mm(d) glass
24、 cloumn , pack wth 5 mm absorbent cotton at the bottom of the column and fll n 20 mm anhydrous sodium sulfate, 10 9 florsl , fill in 20 mm anhydrous sodum sulfate at top. Add 30 mL of n-hexane wash before use. 3. 4 Procedure 3.4. 1 Extracton Wegh ca 5 9 of the test sample(accurate to 0.01 g) nto a 1
25、00 mL beaker. Add 15 rnL water and stand to 2 hours. Add 30 mL acetone , mxed 2 mn n hgh speed blender, flter the extracted solu ton wth a flter paper , collect the fltrates quantitatively in 50 mL volunetric flask with acetone. Transfer 20. 0 mL filter solution into a 250 mL separatory funnel which
26、 is added 50 mL sodium chlo ride solution(3. 2. 4) and 25 mL n-hexane, shake vigorously for 2 mn , let stand to separatng , Add 25 mL n-hexane to water laer， repeat the operation again. Combine the n-hexane layers through col umn of anhydrous sodium sulfate(3. 3. 4) nto a 100 mL round bottom flask t
27、o nearly dryness at rota ry vacuum evaporator bfeow 450C . 3. 4. 2 Cfeanup Add 2 mL n-hexane and 2 mL n-hexane to dissofve the residue , transfer the above sofution into cof umn(3.3.酌，efuted with 100 mL efuting sofution(3. 2. 5). Collect aff the efuted sofuton and rotary vacuum evaporate to dryness
28、below 450C. Add exactly 2.0 mL n-hexane to dssolve the residue , the solution is ready for GC determnation. 3.4. 3 Determnation 3.4.3.1 GC operating condition 8 a) Chromatographc column: Fused slica capillary column , Ultra 2 25 m X 0.32 mm (id) X 0.52 m (film thickness) ,composition: 5% dphenyl and
29、 95%dimethyl polysiloxane; b) Carrier gas and make-up gas: Nitrogen(purity99. 999%) , Flow rate of carrier gas: 5.0 mL/min, flow rate of make-up gas: 20 mL/min, flow rate of hydrogen: 3.5 mL/min, flow rate of air: 110 mL/min; SN/T 1594-2005 c)丁emperatureprogramme: 700C (keep 1 min) ,250C /min to 280
30、0C Ckeep 8 min); d) Injection port temperature: 250 C ; e) Detector temperature: 3000C ; f) Purge valve: 1 min on; g) Inection mode: Splitless; h) Injection volume: 2L; i) The voltage of the bead should be adjusted good condition. 3.4.3.2 GC determination According to the concentrations of buprofezi
31、n , select the standard working solution with similar peak area to that of sample solution. The responses of buprofezin in the standard working solution and the sample solution should be within the linear range of the instrumental detection. The standard working solution should be randomly injected
32、in between the injections of sample solution of equal volume. Under the above GC operating condition , the retention time of buprofezin is about 12.3 min. For chromatogram of the standard see Figure A. 1 in annex A. 3. 4. 3. 3 Blank test The operation of the blank test is the same as the described i
33、n the method of determination , but with the omission of sample addition. 3.4.3.4 Calculation and expression of result The blank value should be subtracted from the above result of calculation. calculation the content of buprofezin residue in the test sample by GC data processor or according to the
34、formula (1): AXcXV x=一一一一一一 C 1 ) A , Xm Where: X一一theresidue content of buprofezin in the test sample , mg /kg; A一一一thepeak area of buprofezin in sample solution, m2 ; As一一一-thepeak area ofmulti organophosphorus in standard working solution，m勺C一一一theconcentration of multi organophosphorus in workin
35、g solution，g/mL; V一一-thefinal volume of the sample solution , mL; m-Mass of test sample , g. 4 Limit of determination and recovery 4. 1 Limit of determination The limit of determination of this method is 0.01 mg /kg 4. 2 Recovery buprofezin 0.01 mg/I唱，therecovery is 82% .100%; buprofezin 0.02 mg/kg,
36、 the recovery is 80% .100%; buprofezin 0.2 mg/阔，therecove叩is85% .100%. 9 SN/T 1594-2005 10 Annex A ( informative) Chromatogram of the standard Buprofezin 上唱. Fig. A. 1 Gas chromatogram of buprofezin IR/min 由CON-gm二Zm中华人民共和国出入境检验检疫行业标准进出口茶叶中嚷嚷翻残留量检验方法气捆色谱法SN/T 1594一2005* 中国标准出版社出版发行北京复兴门外三里河北街16号邮政编码:100045网址电话:6852394668517548 中国标准出版社秦皇岛印刷厂印刷* 印张1字数18千字2005年8月第一次印刷开本880X 1230 1/16 2005年8月第版母定价10.00元如有印装差错由本社发行中心调换版权专有侵权必究举报电话:(010)68533533书号:155066 2-16338
