SN T 1117-2002 进出口茶叶中多种菊酯类农药残留量的检验方法.pdf

1、; 中华人民共和国出入境检验检疫行业标准SN /T 1117-2002 进出口茶叶中多种菊醋类农药残留量检验方法Method for the determination of multiple pyrethroid residues in tea f or import and export 2002- 05-20发布2002 -11-01实施中华人民共和国发布国家质量监督检验检瘦总局中华人民共和国出入境检验检疫行业标准进出口荼叶中多种菊醋类农药残留量检验方法SN/T 1117-2002 晤中国标准出版社出版北京复兴门外三里河北街16号邮政编码:100045电话:685239466851754

2、8 中国标准出版社秦皇岛印刷厂印刷* 开本880X12301/16 印张1字数10千字2002年9月第一版2002年9月第-次印刷印数1一2000 书号:155066.2-14719 定价10.00元网址版权专有侵权必究举报电话:(010)68533533SN/T 1117-2002 前本标准是按照GB/T1. 1-2000(标准化工作导则第1部分z标准的结构和编写规则及SN/T 0001一1995(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。其中测定方法是参考国内外有关文献，经研究、改进和验证后制定的。本标准同时制定了抽样和制样方法。测定低限是根据国际上对

3、茶叶中各种拟除虫菊醋残留量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。本标准由中华人民共和国浙江出入境检验检疫局负责起草。本标准主要起草人z丁慧瑛、鲍晓霞、郑自强。本标准系首次发布的出入境检验检疫行业标准。SN/T 1117-2002 迸出口茶叶中多种菊醋类农药残留量检验方法1 范围本标准规定了进出口茶叶中多种菊酶残留量检验的抽样、制样和气相色谱测定方法。本标准适用于进出口茶叶中联苯菊醋、甲氟菊醋、三氟氯辄菊醋、氯菊醋、氯辄菊醋、辄戊菊醋、澳氯菊醋残留量的检验。2 抽样和制样2.1 栓验批以不超过2000箱为一检验批。同一检验

4、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 抽样敢量(见表1)囊1单位为件批量件数最低抽样件数1-5 1 6-50 7 51-500 11 501-1 000 16 1001-1 500 19 1 501-2 000 20 2.3 抽样方法接2.2规定的抽样件数随机抽取，逐件开启。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500g-l 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20目筛，均分成两份，装人洁净的容器内，作为试样。密封，并标明标记。2.5 试样保存将试样于一

5、180C以下冷冻保存。注z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 方法提要用丙酣和水将残留的菊醋类农药从样品中提取出来，正己烧反萃取，然后用乙腊萃取，弗罗里硅土柱净化，用带电子捕获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，试剂均为分析纯，水为蒸锢水。I SN/T 1117-2002 3.2.1 乙醋、正己烧、乙腊、丙酣。3.2.2 15%氯化铀水溶液z称取15g氯化铀溶解于100mL水中。3.2.3 洗脱液z正己烧-乙酶(体积比.7十3)。3.2.4 无水硫酸铀:6500C灼烧4h.在干燥器内冷却至室温，贮于密封瓶中备

6、用。3.2.5 弗罗里硅土:60目-100臼。650C灼烧4h，使用前天130C活化4h.在于燥器内冷却至室温，加2%的水脱活，备用。3.2.6 脱脂棉。3.2.7 提取剂1:正己烧加入少量乙睛饱和，摇匀。3.2.8 提取剂:乙脯加入少量正己烧饱和，摇匀。3.2.9 联苯菊醋、甲辄菊醋、三氟氯辄菊醋、氯菊醋、氧戊菊醋、氯辄菊醋、澳辄菊醋标准品:纯度99%。3.2.10 联苯菊醋、甲佩菊醋、三氟氯佩菊醋、氯菊醋、氯氟菊醋、氟戊菊醋、澳佩菊醋标准储备溶液z分别准确称取0.0100g标准品(3.2.的，用正己烧溶解定容至100mL.溶液浓度为100周/mL。根据需要用正己烧稀释混合至适当浓度的棍合标

7、准工作液。3.3 仪器和设备3.3.1 气相色谱仪，配有电子捕获检测器。3.3.2 旋转蒸发器。3.3.3 均质器。3.3.4 微量注射器:10L。3.3.5 无水硫酸铀柱:80mmX40 mm(内径)筒形漏斗，底部垫5mm高脱脂棉，再装50mm高无水硫酸铀。3.3.6 净化柱:200 mmX 15 mm(内径)玻璃柱，底部填约5mm高脱脂棉和20mm高无水硫酸铺，10 g弗罗里硅土，顶端加20mm高无水硫酸销，使用前用20mL正己烧淋洗。3.3.7 容量瓶:10mL、50mL。3.3.8 分液漏斗:125mL。3.4 测定步骤3.4.1 提取和净化称取5g磨碎的均匀试样(精确到0.1g).置

8、于100mL三角烧瓶中，加入15时，水浸泡2h。加入30 mL丙圃，在均质器中均质2min.过滤。滤液用丙嗣定容至50mL。精确移取20mL滤液至预先装有50mL氯化纳水溶液(3.2.2)和25mL正己烧的125mL分液漏斗中，激烈振摇，静置，将正己烧层过无水硫酸铀柱(3.3.5)至浓缩瓶中。水相中.再加入25mL正己烧，重复操作，合并正己烧层，50C以下水浴减压浓缩至约2mL。用20mL提取剂1(3.2.7)以及20mL提取剂:n(3.2.8)淋洗浓缩瓶并榕解残渣。将溶液分别转移.至同一125mL分液漏斗中，激烈振摇2min，静置，分去乙腊层于另一分液漏斗中，在正己烧层中再加入20mL提取1

9、fIJn (3.2.的，重复上述操作，合并乙脯层于上述分液漏斗中，加入30mL提取剂I(3.2.7)，激烈振摇2min.静置，分去乙腊层于100mL浓缩瓶中，在650C以下水浴减压浓缩至于。残渣分别用5mL正己烧溶解洗涤二次，将此液体移人净化柱(3.3.6)中，用80mL洗脱液(3.2.3)洗脱。收集全部洗脱液，在50C以下水浴上减压浓缩至干，用2mL正己烧榕解定容，供GC测定。3.4.2 测定3.4.2.1 色情条件a) 色谱柱z石英毛细管柱.HP-1701，30mXO. 25 mm(内径)X 0.25m(膜厚).或相当者;b) 载气、尾吹气:氮气(纯度99.999%);载气流速1.0mL/

10、min;尾吹气流速:60mL/min; c) 柱温:70C保持1min，以每分钟20C的升温速率升温至280C，保持25min; 2 SN/T 1117-2002 d) 进样口温度:280C;e) 检测器温度:3000C;f) 进样方式:不分流进样zg) 进样量:2L。3- 4. 2. 2 色谱测定根据样液中各种菊醋含量的情况，选定峰面积相近的标准工作溶液。标准工作洛液和样液中各种菊醋的响应值均应在仪器检测的线性范围内。标准工作溶液和样液等体积穿插进样测定。在上述色谱条件下联苯菊醋的保留时间约为8.9min;甲氟菊醋的保留时间约为9.9min;三氟氯佩菊醋的保留时间约为1l.9min;氧菊醋各

11、异构体的保留时间为12.1min;12. 5 min;氯氟菊醋各异构体的保留时间分别约为16.2min , 16. 8 min , 17. 0 min , 17. 4 min;氧戊菊醋各异构体的保留时间分别约为20.1mn. 21.3 min;澳氧菊醋的保留时间约为24.7mn。标准品的色谱图见附录A中图A.1。3. 4.3 空白试验除不加试样外，均按上述操作步骤进行。3- 4. 4 结果计算和表述用色谱数据处理机或按式。)计算试样中各种菊醋的残留含量zV一-m c一-s -A A-X .( 1 ) 式中zX一一试样中各种菊醋的残留含量，mg/kg;A一一样液中各种菊醋的峰面积，有异构体的菊醋

12、须计算各异构体的峰面积之和zA. -标准工作液中各种菊醋的峰面积，有异构体的菊醋须计算各异构体的峰面积之和zC一一一标准工作液中各种菊醋的故度，用/mL;V一样液最终定容体积.mL;m 最终样液所代表的试样量.g。注:计算结果需扣除空白值。4 测定低限和回收率4.1 本方法对下列农药的测定低限为甲氧菊醋。.01mg/kg;三氟氯氯菊醋0.005 mg/kg;联苯菊醋。.05mg/kg;氯菊醋。.05mg/kg;氧戊菊醋0.05 mg/kg;氯氧菊醋。.05mg/kg;澳氧菊醋0.05 mg/kg 4.2 回收率回收率的实验数据(在不同添加浓度范围内)如下:联苯菊醋浓度在O.051. 0 mg/

13、kg范围内，回收率为70.0%82. 6%; 甲氧菊醋浓度在O.01 O. 2 mg/kg范围内，回收率为85.0%98. 0%; 三氟氯氧菊醋浓度在O.005O. 1 mg/kg范围内，回收率为92.O%103. 0%; 氯菊醋浓度在O.051. 0 mg/kg范围内，回收率为86.0%98. 2%; 氯 99% . 3.2.10 Stock satandard solution of bifenthrin , fenpropathrin , cyhalothrin , permethrin , cyperme thrin ,fenvalerate , deltamethrin:accura

14、te weigh 0.010 0 g Satandard (3.2.9) , dissolve with n-hex ane and quantitatively on 100 mL, these concentration of solutions are 100g/mL. According to the requirement , is prepared from the stock solution in n-hexane and diluted to the reguired concentra tion. 3.3 Apparatus and equipment 3.3.1 Gas

15、chromatography: with electron capture detector. 3.3.2 Rotary vacuum evaporator:with temperature-controlled water bath. 3.3.3 High speed blender. 3.3.4 Micro syringe:10L 3.3.5 Column of anhydrous sodium sulfate:80 mm x 40 mm(id) cylinder funnel ,pack with 5 mm defatted co忧。nat the bottom of the colum

16、n and fill in 50 mm anhydrous sodium sulfate. 3.3.6 Column for clear-up:200 mm x 15 mm(id) glass cloumn , pack with ca 5 mm defatted cot ton at the bo忧omof the column and fill in 20 mm anhdrous sodium sulfate, 10 g florisil , fill in 20 mm anhydrous sodium sulfate at top. Rinse the column with 20 mL

17、 of n-hexane before use. 3.3.7 Volumetric flask: 10 mL,50 mL. 3.3.8 Separatory funnel: 125 mL. 3.4 Procedure 3.4.1 Extraction and cleanup Weigh ca 5 g of the test sample( accurate to 0.1 g) into a 100 mL flask with stopper. Marinate the test sample in 15 mL of water for 2 h .Add 30 mL acetone , mixe

18、d 3 min in high speed blender, filter the above extracted solution with a filter paper ,collect the filtrates quantitativelin 50 mL volunet ric flask with acetone. Accurately transfer 20 mL filter solution into a 125 mL separatory funnel which is added 50 mL sodium chloride sOlution(3.2.2) and 25 mL

19、 n-hexane ,shake vigorously for 8 SN/T 1117-2002 2 min, let stand for separating , n-hexane layer through column of anhydrous sodium sulfate (3.3. 5) into a 100 mL round bottom flask. Water layer add 25 mL of n-hexane, repeatly operate ,concen trate to above 2 mL on Rotary vacuum evaporator bleow 50

20、C . Rinse the round bottom with 20 mL of extracte solution 1 (3.2.7) and extracte solution n (3.2.8) and dissolve residue. The solution transfer into the same 125 mL separatory funnel , shake vigor ously for 2 min, let stand to separating. Orain the acetonitrile layer into a 125 mL separatory fun ne

21、l ,n-hexane layer add 20 mL of extracte solution n (3.2.8) , repeatly operate.Combine the ace tonitrile layers into same separatory funnel , add 30 mL of extracte solution 1 (3.2.7) , shake vigor ously for 2 min, let stand to separating. Orain the acetonitrile layer into a 100 mL round bottom flask

22、to dryness at Rotary vacuun evaporator below 65C. Add 5 mL of n-hexane to dissolve the residue twice thme, transfer the above solution into column (3.3.6) , elutet with 80 mL eluting solution(3.2.3).Collect all the eluantion solution and Rotary vacuum evaporate to dryness below 50C . Add exactly 2 m

23、L of n-hexane to dissolve the residue , the solution is ready for GC determination. 3.4.2 Oetermination 3.4.2.1 GC operating condition a) Chromatographic column: Fused silica capillary column , HP-1701 , 30 m x 0.25 mm( id) x 0.25 m(film thickness) , or equivalent; b) Carrier gas and make-up gas:Nit

24、rogen , (purity99.999%); Flow rate of carrier gas: 1 .0 mL/min. Flow rate of make-up gas: 60 mL/min; c) Column temperature:70C keep 1 min ,as rate of temperature of 20C/min raise to 280C ,keep 20 min; d) Injection port temperature: 280C ; e) Oetector temperature:300C; f) Injection mode: splitless; g

25、) Injection volume:2L. 3.4.2.2 GC determination According to the contents of multiple pyrethroid in the sample solution , select the standard work-9 SN/T 1117-2002 ing solution with similar peak area to that of sample solution. The responses of multiple pyrethroid in the standard working solution an

26、d the sample solution should be within the linear range of the instrumental detection. The standard working solution should be randomly injected in between the injections of sample solution of equal volume. Under the above GC operating condition , the reten tion time of bifenthrin is about 8.9 min;

27、the retention time of fenpropathrin is about 9.9 min; the retention time of chalothrin is about 11 .9 min; the retention time of permethrin isomer is about 12.1 min, 12.5 min;the retention time of cypermethrin isomer is about 16.2 min, 16.8 min , 17.0 min, 17.4 min;the retention time of fenvalerate

28、isomer is about 20.1 min;21.3 min;the retention time of deltamethrin is about 24.7 min. For chromatogram of the standard , see Figure A. 1 in an nex A. 3.4.2.3 Blank test The operation of the blank test is the same as the described in the method of determination, but with the omission of sample addi

29、tion. 3.4.2.4 Calculation and expression of result Calculation the content of multiple prethroid residue in the test sample bGC data processor or according to the formula( 1): X=A x C x V = As x m 、，A ，、. . . . . . . . . . . . . . . . . . . . . . . . . . where X一一theresidue content of multiple pyret

30、hroid in the test sample, mg/kg; A-一-thepeak area of multiple pyrethroid in sample solution,calculate the total of peak area for pytehroid isomers when exist isomers; As 一-thepeak area of multiple pyrethroid in the standard working solution ,calculate the total of peak area for pyteyhroid isomers wh

31、en exist isomers; c-the concentration of multiple pyrethroid in the standard working solutionllg/mL; V一一-thefinal volume of the sample solution,mL; m一-thecorresponding mass of the test sample in the final sample solution , g. Note: The blank value should be subtracted from the above result of calcul

32、ation. 4 Limit of determination and recovery 4. 1 Limit of determination The limit of determination of this method are: Fenpropathrin 0.01 mg/kg;cyhalothrin 0.005 mg/kg; bifenthrin 0.05 mg/kg; permethrin 0.05 mg/ kg; cypermethrin 0.05 mg/kg; fenvalerate 0.05 mg/问;deltamethrin 0.05 mg/kg. 10 SN/T 111

33、7-2002 4.2 R艇。IveryAccording to the experimental data , the corresponding recoveries of fortifying concentrations are: bifenthrin 0.05陶，.0 mg/kg, the recovery is 70.0% - 82.6% ; fenpropathrin 0.1 - 0.2 mg/kg, the recoveris 85.0% - 98.0%; cyhalothrin 0.005 - 0.1 mg/kg, the recovery is 92.0% - 103.0%

34、; permethrin 0.05 - 1.0 mg/kg, the recovery is 86.0% - 98.2%; cypermethrin 0.05 -.0 mg/kg,the recovery is 88.0% - 102.4%; fenvalerate 0.05 - 1.0 mg/kg, the recovery is 91 .0%句104.0%; deltamethrin 0.05 - 1.0 mg/kg, the recovery is 90.0% - 107.0%. NOON-hFFFHZm SN/T 1117-2002 Annex A (informative) .Chr

35、omatogram of the standard NH由.四Hz 400 350 同的同.ON300 150 50 100 250 200 15 Fig:8.91 min一bifenthrin(O.05g/mL) 9.91 min-fenpropathrin(0.01g/mL) 11.95 min-cyhalothrin(O.S闯ImL)12.05 mn , 12.51 min-permethrin(0.05g/mL) 16.18 min ,16.81 min ,17.01 min,17.39 min-cypermethrin(0.05g/mL) 20.13 min ,21.30 min-fenvalerate(0.05g/mL) 24.69 min-deltamethrin(0.05g/mL) Fig A.1-Gas chromatogram of multiple pyrethroid standard 25min 20 10 5 。侵权必究书号:155侃62-14719定价:10.元* 版权专有