1、户:才己|中华人民共和国出入境检验检疫行业标准SN/T 1017. 1-2001 出口粮谷中环庚草酷残留量检验方法Method for the determination of cinmethylin residues in cereals for export 2001-12 -30发布2002 - 06 -01实施中华人民共和国发布国家质量监督检验检瘦总局SN/T 1017.1-2001 前言本标准是按照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1部分:标准编写的基本规定及SN/T0001-1995(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
2、规定的要求编写的。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粮谷中环庚草酷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是提示的附录。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:朱宏、朱晓雨、郑自强、丁丽娟。本标准首次发布。范围中华人民共和国出入境检验检疫行业标准出口粮谷中环庚草酷残留量检验方法Method for the determination of cinmethylin residues in cereals for expor
3、t SN/T 1017.1-2001 本标准规定了出口粮谷中环庚草醒残留量检验的抽样、制样和气相色谱一质谱测定方法。本标准适用于出口糙米中环庚草酷残留量的检验。2 抽样和制样2.1 检验批以不超过4000袋(200t)为一检验批。同一检验批的商品应具有相同的特征，如包装、标记、产地、规格和等级。2.2 抽样数量按式(1)计算抽取袋数=y百式中:N一全批袋数; 抽样袋数。注:a值取整数，小数部分向前进位为整数。2.3 抽样工具. ( 1 ) 2. 3. 1 单管取样器:不锈钢管，全长55cm(包括于柄)，直径1.5 cm2. 0 cm，沟槽长度应超过袋对角线长度的半。2.3.2 取样铲02. 3
4、- 3 分样板。2.3.4 样品筒(袋):可密封。2.3.5 分样布或适用铺垫物。2.4 抽样方法2.4.1 倒包抽样从堆垛的各个部位随机抽取2.2中规定的应抽样件数的10%(每批一般不少于3袋)，将袋口缝线全部拆开，平置于分样布或其他洁净的铺垫物上，双手紧握袋底两角，提取约成45。倾角，倒拖约1m，使袋内货物全部倒出。查看袋内和袋间品质是否均匀。确认情况正常后，用取样铲随机在各部位抽取样品，立即将样品倒入盛样器内。每袋抽取样品数量应基本一致。2.4.2 袋内抽样按2.2中规定的应抽样袋数的90%，在堆垛四周上、中、下各层以曲线走向随机抽取。将取样器管中华人民共和国国家质量监督检验检应总局20
5、01-12-30批准2002- 06-01实施SN/T 1017.1-2001 槽朝下，从每袋一角依斜对角方向插入袋内，然后将管槽旋转朝上，抽出取样器，立即将样品倒入盛样容器内。每袋抽取样品数量应与2.4.1基本一致。每批样品总量应不少于4kg。2.4.3 大样缩分集中袋内抽样和倒包抽样所取全部样品，倒于分样布上，用分样板按四分法缩分出样品不少于2 kg，装入盛样器内，加封后标明标记并及时送交实验室。2. 5 试样制备将样品按四分法缩分出约1峙，全部磨碎并通过20目筛，由匀后均分成两份，分别装入洁净容器内作为试样，密封并标明标记。2.6 试样保存将试样于一5C以下避光保存。注:在抽样和制样的操
6、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 方法提要试样中环庚草醋经丙酣、水提取，用正己烧抽提，经弗罗里硅土柱净化，用乙酷-正己烧(10十90)洗脱液洗脱，浓缩后定量加入甲醇，用配有质谱检测器的气相色谱仪以选择离子监测方式(GC/MSDSIM)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，水为蒸馆水。3. 2. 1 甲醇，丙酬，乙酶，正己烧均需重蒸悟。3. 2. 2 氧化铀溶液:5%，将50g氧化铀溶于1000 mL水中。3. 2. 3 洗脱液:正己皖乙酷(90十10)。3. 2. 4 无水硫酸铀:650C灼烧4h，置于干燥器中备用。3
7、. 2. 5 弗罗里硅土:60目100日，6500C灼烧4h，置于干燥器中备用，用前130C烘4h，在干燥器内冷却至室温，加3%水脱活。3. 2. 6 环庚草酷标准品:纯度二三98%。3. 2. 7 环庚草酷标准洛液:准确称取适量的环庚草酷标准品中，用甲醇配成浓度为0.10mg/mL标准储备榕液，根据需要再用甲薛稀释成适当浓度的标准工作榕液。I3. 3 仪器和设备3. 3. 1 气相色谱仪:配有质谱检测器和毛细管不分流进样系统。/3. 3. 2 旋转蒸发器。3. 3. 3 层析柱:180mmX20 mm(id)，内装约0.5cm高的脱脂棉，1cm高的无水硫酸纳，6.0g弗罗里硅土，1cm高的元
8、水硫酸铀。使用前用20mL正己皖淋洗。3. 3. 4 硫酸铀柱:7. 5 cm X 1. 5 cm (id) ，内装5cm高无水硫酸铀。3. 3. 5 振荡机。3. 3. 6 兰角烧瓶:100 mL。3. 3. 7 分液漏斗:250 mLo 3. 3. 8 浓缩瓶:150 mL。3. 3. 9 离心管:10 mLo 3.3.10 微量注射器:10L 3.4 测定步骤3. 4. 1 提取和净化2 SN/T 1017.1二2001称取10g试样(精确到0.1g)置于100mL三角烧瓶中，加入20mL水，浸泡2h，再加入50mL丙酬，振荡10min，过滤。残渣用20mL丙酣再提取一次。滤液合并于25
9、0mL分液漏斗中，加入50mL氧化铀榕液，用50mL、30mL正己:境提取。合并正己炕层，过无水硫酸铀柱脱水，收集流出液于45C水浴上旋转浓缩至近干。用5mL正己烧恪解残渣，并将溶液转移至层析柱内，加30mL正己烧淋洗，弃去流出液。用加40mL正己烧乙酿(90+10)洗脱液洗脱，控制洗脱速度(约1mL/min)，收集洗脱液，于45C水浴上旋转浓缩至近干。加5mL甲醇榕解并转移至离心管中，供气相色谱质谱检测器测定。J 4. 2 测定J 4. 2.1 气相色谱质谱条件a)色谱柱:HP-5，30 mX 0.25 mm(id) X 0.25m熔融石英毛细管柱或相当的色谱柱;30C /min 10 b)
10、柱温:60C (1 min)一一一-+18 0 C一一一一一250C(5 min) ; c)进样口温度:250C;d)色谱质i普接口温度:280C;e)载气:氮气，纯度二三99.999%，流量1.0 mL/min; f)进样量:2L; g)进样方式:无分流进样，1min后开阀;h)电子轰击源(EI); i)电离能量:70eV; j)测定方式:选择离子监测方式(SIM); k)选择监测离子(m/z):105 , 123 , 169 U; 1)溶剂延迟:6min。J 4.2.2 色谱质谱测定根据样液中环庚草酷含量的情况，选定峰面积相近的标准工作溶液。标准工作溶液和样液中环庚草酷的响应值均应在仪器检
11、测的线性范围内。标准工作榕液和样液等体积参插进样测定。在上述色谱条件下，环庚草隘的保留时间约为9.6mino标准品的总离子流色谱图见i附录A中图A1。3.4.3 空白试验除不加试样外，均按上述测定步骤进行。J 4. 4 结果计算和表述用色谱数据处理机或按式(2)计算试样中环庚草酷的残留含量:x = A. c. V = 一一一. ，四.( 2 ) , Ao .m 式中:X一一试样中环庚草酷的残留含量，mg/kg;A一一一样液中环庚草酷的峰面积，mm2;A, 标准工作液中环庚草酷的峰面积，mm气C-标准工作液中环庚草隘的浓度，g/mL;V二一样液最终定容体积，mL;m一-最终样液所代表的试样量，g
12、0 注:计算结果需扣除空白值。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/kg。4.2 回收率3 4 SN/T 1017.1-2001 糙米中环庚草酷添加浓度及其回收率的试验数据:在0.01mg/kg添加水平时，回收率为94.8%; 在0.10mg/kg添加水平时，回收率为95.4%; 在0.20mg/kg添加水平时，回收率为92.5%。响应值3500 3000 2500 2000 1500 1000 500 。SN/T 1017.1-2001 附录A(提示的附录)标准晶色谱图1气、L啕.A._.r气、_L.JL_._ -. -、严仇_. _. . -. -人7.00
13、 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 时间/min图Al环庚草酷标准品的总离子流色谱图(SIM)5 SN/T 1017.1-2001 Foreword This standard was drafted in accordance with the requirements of GB/T 1.1-1993 Directives for the work of standardization-Unit 1: Drafting and presentation of standard-Part 1: General rules
14、for drafting standards and SN/T 0001-1995General rules for drafting the standard method for the determination of pesticide , veterinary drug residues and biotoxins in commodities for export . The method of determination of this standard was drafted by referring to relevant domestic and foreign liter
15、atures through research , modification and verification .In addition , methods of sampling and sample preparation are also specified in this method. The limit of determination in this standard is defined on the bases of the current international max imum limit for cinmethylin residues in cereals aii
16、dthe sensitivity of the method. Annex A of this standard is an informative one. This standard was proposed by and is under thecharge of China N 3tional Regulatory Commission for Certification and Accreditation. This standard was drafted by Zhejiang Entry:Exit-lnspection-ahd Quarantine Bureau of the
17、People s Republic of China. The main drafters of this standard are Zhu hong ,Zhu xiaoyu ,Zheng ziqiang and Ding lijuan. This standard is promulgated for the first time. Note: This English version , a translation from the Chinese text , is solely for guidance. 6 Professional Standard of the People s
18、Republic of China for Entry-Exit Inspection and Quarantine SN/T 1017.1-2001 Method for the determination of cinmethylin residues in cereals for expo同1 Scope This standard specifies the methods of sampling , sample preparaton and determination of cin methylin residues by GC/MS (SIM) in cereals for ex
19、port. J / 丁hisstandard is applicable to the determination of cinmethylin rsidues in unpolished rice for ex port. 2 Sampling and sample preparation 2.1 Inspection lot Each inspection lot should not exceed 4 000 bage (200 t) . 丁hecharacteristics of the cargo within the same inspection lot, such as pac
20、king , mark, origin , speci fication , grade ect , should be the same. 2.2 Quantity of sample taken The number of bags to be sampled shall be calculated according tq the formula( 1) : =;-百一.1. ( 1 ) where N-total number of bags in a lot; -number of bags to be sampled. Note: if value is with decimal
21、, round off the decimal pa町，whichis added as udtiy to the lntegral pa同of. 2.3 Sampling tools / 2.3. 1 Metallic sampler: Stainless steel tbe , length一(includinghandle): 55 cm , diameter: 1.5 cm 2.0 cm , groove length: longer than half of bag s diagonal length. 2.3.2 Sampling shovel. 2.3.3 Plate for q
22、uartering. 2.3.4 Sample can (bag) , which can be sealed. Approved by General Administration of Quality Supervision , Inspection and Quaran tine of the People s Republic of China on 2001-12-30 Implemented from 2002-06-01 7 SN/T 1017.1-2001 2.3.5 Cloth (or other suitable material) sheet:For sample div
23、iding(quartering). 2.4 Sampling procedure 2.4.1 Sampling by emptying out Draw 10% of the number of bags specified in 2.2(not less than 3 bags) at any part of the pile at random. Unseam and open the bag , and lay it on a clean cloth sheet( or other clean sheet) . Grasp tight two corners of the bag bo
24、ttom and rasie up to an angle of 450, tug backward for ca 1 m until all content of the bag is emptied out. Check whether the quality of goods is uniform within and be tween the bags. After confirming the goods are in normal condition , scoop up the sample from dif ferent pa叫sof the outpoured content
25、 with a shovel , and place in sample container promptly. The quantity of sample drawn from each bag should be bascially the same. 2.4.2 Sampling from inside the bags Draw the sample from 90% of the number bags specified in 2.2 as follows: Along the sine wave of the pile , draw samples from the bags
26、of the upper, middle and lower parts of the pile at random. Insert the sampl町，withits groove facing downward , diagonally into each bag , then turn the sam pler by 1800, draw out the sampler, and promptly pour the sample into a container. The quantity of the sample drawn from each bag should be basi
27、cally the same as in 2.4.1. The total weight of the gross sample of each lot should not be less than 4 kg. 2.4.3 Reduction of gross sample Pour all of samples on a clean sheet , reduce to not less than 2 kg with a plate by qua时ering.Place in a sample container, seal , label and send to the laborator
28、in time. 2.5 Preparation of test sample Reduce the sample to ca 1 kg by quartering , grind thoroughly and let pass through a 20 mesh sieve , mix thoroughly and divide into a equal portion. Each portion is placed in a clean container as the test sample , sealed and labeld. 2.6 Storage of test sample
29、The test samples shall be stored below - 50C and kept away from light. Note: In the course of sampling and sample preparation , precautions must be taken to avoid the contamination or any factors which may cause the change of residue content. 3 Method of determination 3.1 Principle The cinmethylin r
30、esidues in test sample are extracted with acetone and water. The extract is further extracted with n-hexane, the n-hexane solution is cleaned up by passing through a column filled with frorisil. The analyte is eluted with ether-n-hexane (10 + 90) . The eluate is concentrated and made up to a definit
31、e volume with methanol. The solution is used for GC determination with MSD in SIM mode using external standard method for quantitation. 3.2 Reagents and materials Unless otherwise specified , all of the reagent used should be analytically pure. water is distilled one. 8 SN/T 1017.1-2001 3.2.1 Methan
32、ol , acetone , ether , n-hexane: Redistilled. 3.2.2 Sodium chloride solution:5% , dissolve 50 9 of sodium chloride in 1 000 mL water. 3圄2.3Eluate: Ether-n-hexane(90 + 10). 3.2固4Anhydrous sodium sulfate:lgnite at 6500C for 4 h , store in a desiccator for use. 3.2圄5Frorisil: 60 - 100 mesh , Ignite at
33、6500C for 4 h , store in a desiccator. Heat at 130C for 4h , deactivate with 3% of water before use. 3.2.6 Cinmethylin standard: Purity注98%.3.2.7 Cinmethylin standard solution: Accurately weigh an appropriate amount of cinmethylin standard and dissolve with methanol to prepare a standard stock solut
34、ion of 0.10 mg/mL in con certration , then dilute the standard stock solution with methanol to the required concentration as standard working solution. 3.3 Apparatus and equipment 3.3.1 Gas chromatograpl1equipped with mass selective detector and capillary splittless inlet. 3.3.2 Rotaryevaporator. 3回
35、3.3Cleanup column:180 mm x 20 mm(id) glass column , packed with ca 0.5 cm height of ab sorbent cotton at bottom , then with 1 cm height of anhydrous sodium sulfate , 6.0 9 frorisil , 1 cm height of anhydrous sodium sulfate , elute with 20 mL n-hexane before use. 3.3.4 Sodium sulfate column:7.5 cm x
36、1.5 cm(id) , prepacked with 5 cm height of anhydrous sodium sulfate. 3.3.5 Shaker. 3.3囚6Concial flask:100 mL. 3.3.7 Separatory funnel:250 mL. 3圄3回8Evaporating flask: 150 mL. 3.3.9 Centrifuge tube: 10 mL. 3.3.10 Micro-syringe: 10L 3.4 Procedure 3.4.1 Extraction and cleanup Weight ca 10 9 of the test
37、sample(accurate to 0.1 g)into a 100 mL concial flask.Add 20 mL water, soak for 2 h , add 50 mL acetone shake for 10 min , and then filter, extract the residues once more with 20 mL acetone.Combine the filtrates in a 250 mL separatory funnel.Add 50 mL sodium chlo ride solution , and then extract with
38、 50 mL and 30 mL n-hexane respectively. Combine the n-hexane SN/T 1017.1-2001 layers and let pass through a column of anhydrous sodium sulfate for dehydration. Coliet the efflu ent and rotary-evaporate to near dryness in a water bath at 450C , Dissolve the residue with 5 mL n hexane and transfer to
39、cleanup column , rinse with 30 mL n-hexane , discard the effluents. Elute with 40 mL ether-n-hexane (90+ 10) eluate (flow rate 1 mL/m in)and collect all eluates.Rotaryevapo rate to near dryness at 45 0C water-bath. Dissolve and make up to 5 mL with methanol , the solution is used for GC/MS analysis.
40、 3.4.2 Determination 3圄4.2.1GC/MS operating condition a) Chromatographic column:HP-5 ,30 mxO.25 mm(id) xO.25m capillary column of fused silica or equivalent; 30 oC/min 10 C /min b) Column temperature:60OC (1 min)一一一一一1800C一一一一一2500C(5 min) ; c) Injection port temperature:250oC; d) GC/MS interface te
41、mperature:280OC; e) Carrier gas:Helilm，purity99.999%.Flow rate:1.0 mUmin; f) Injection volume: 2L; g) Injector mode: Injecting on splitless , valve open 1 min later. h) Electron impact source(EI); i) lonizing voltage: 70 eV; j) Determination mode:Selected ion monitoring(SIM) mode; k) Selected monito
42、ring ion(miz):105, 123 , 169 u; 1) Solvent deliver:6 min. 3.4.2.2 GC/MS determination According to the approximate concentration of cinmethylin in the sample solution , select the stan dard working solution with similar the peak area to that of sample solution. The responses of cin methylin in the s
43、tandard solution and the sample solution should be within the linear range of the instrumental detection. The standard solution should be randomly injected in between the injec tions of sampie solution of equal volume. Under the above chromatographic operating condition , the retention time of cinme
44、thylin is about 9.6 min. For total ion chromatogram of the cinmethylin standard , see fig. A 1 in annex A. 3.4.3 81ank test The operation of the blank test is the same as that described in the method of determination , but without addition of sample. 3.4.4 Calculation and expression of result The ca
45、lculation of cinmethylin content in the test sample is carried out by GC data processor or ac cording to the formula (2): A. c. V X=一一一( 2 ) As. m where X-the residue content of cinmethylin in the test sample , mg/kg; A-the peak area of cinmethylin in sample solution , mm2; As一thepeak area of cinmet
46、hylin in the standard working solution , mm飞c-the concentration of cinmethylin in the standard working solution，g/mL; V-the final volume of the sample solution , mL; m-the corresponding mass of the tested sample in the final sample solution , g. 10 SN/T 1017.1-2001 Note: The blank value should be su
47、btracted from the above result of calculation. 4 limt of determination and recovery 4.1 Li mit of determination The limit of determination of this method is 0.01 mg/kg. 4.2 Recovery According to the experimental data , the fortifying concentrations of cinmethylin in uppolished rice and its correspon
48、ding recoveries are: 0.01 mg/kg , the recovery 94.8% ; 0.10 mg/kg,the recovery95.4%j 0.20 mg/kg , the recovery 92.5% . OONFSN/T 1017.1-2001 -NFOAnnex A ( informative) Chromatogram of the standard VHZ Abundancc 3500 3000 2500 2000 1500 1000 500 r、 A A 八，、，。16.00 Time/min 15.00 14.00 13.00 12.00 11. 0
49、0 10.00 9.00 8.00 7.00 Total ion chromatogram of cinmethylin standard(SIM) 究M一元必一o权叫一侵趴一叩有另一专4一权号-机版书一副Figure A1 SN/T 1017.1-2001 中华人民共和国出入境检验检疫行业标准出口粮谷中环庚草酷残留量检验方法SN/T 1017.1-2001 .x-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:6852394668517548 中国标准出版社秦皇岛印刷厂印刷-x-开本880X1230 1/16 印张1字数26千字2002年5月第一版2002年5月第一次印刷印数l一2000 只书号:155066 2-14404 定价lO.OO兀网址版权专有侵权必究举报电话:(0
