1、叶己|中华人民共和国出入境检验检疫行业标准SN /T 1115 - 2002 进出口水果中恶草酣残留量的检验方法Method for the determination of oxadiazon residues in fruits 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疫总局SN /T 1115-2002 前本标准是按照GB/T1. 1-2000标准化工作导则第1部分:标准的结构和编写规则及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。
2、其中测定方法是参考了国内外有关文献，经研究、改进和验证后而制定的。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水果中恶草酣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湖南出入境检验检疫局负责起草。本标准主要起草人:李拥军、黄志强、熊芳、张莹、戴华。本标准系首次发布的出入境检验检疫行业标准。SN /T 1115-2002 迸出口水果中恶草嗣残留量的检验方法1 范围本标准规定了进出口水果中恶草酣残留量检验的抽样、制样和气相色谱质谱测定及确证方法。本标准适用于进出口柑桔、苹果中恶草酣残留量的检验
3、。2 抽样和制样2.1 检验批以不起过1500件为一检验批。同一检验批的商品应具有相同的特征，如包装、标记、产地、规格和等级等。2.2 抽样撤量(见表1)表1批量最低抽样数125 1 26100 5 101250 10 2511 500 15 2.3 抽样方法按2.2规定的抽样件数随机抽取，逐件开启。每件至少取500g作为原始样品，原始样品总量不得少于2kgo加封后，标明标记，及时送实验室。2.4 试样制备将所取原始样品缩分出1峙，取可食部分，经组织捣碎机捣碎，均分成两份，装入洁净容器内，作为试样。密封，并标明标记。2.5 试样保存将试样于一180C以下冷冻保存。注:在抽样和制样的操作过程中，
4、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 方法提要试样中恶草酣残留物用苯正己烧提取，然后过活性炭小柱净化，用配有质量选择性检测器的气相色谱仪测定及确证，外标法定量。3. 2 试剂和材料除特殊规定外，所有试剂均为分析纯，水为蒸锢水。3. 2. 1 苯z重蒸馆。3.2.2 正己烧:重蒸榴。SN/T 1115-2002 3.2.3 氯化铺。3.2.4 无水硫酸铀z经650C灼烧4h，置于干燥器中备用。3.2.5 活性碳小柱:SUPELCLEANENVI-CARB小柱，125mg , 3 mL或相当者。3.2.6 苯-正己烧溶液:苯十正己皖0+1)。3.2.7 苯-正己烧溶液:苯
5、+正己皖(2+1)。3.2.8 恶草嗣标准品:纯度99%。3.2.9 恶草嗣储备液:准确称取适量恶草酣标准品，用少量正己烧榕解，并以正己皖配制成浓度为1 000g/mL标准储备液。根据需要再用正己烧将标准储备液稀释成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，配质量选择性检测器。3. 3. 2 固相萃取装置，带真空泵。3. 3. 3 离心机:3000r/min。3. 3. 4 涡旋混匀器。3.3.5 离心管:15mL。3. 3. 6 刻度试管:15 mLo 3. 3. 7 微量注射器:10L。3. 4 测定步骤3.4.1 提取准确称取2.0g均匀试样(精确至0.001
6、g)于15mL离心管中，加入1g氯化铀(3.2. 3) ，于1昆匀器上提匀30S，加入2mL苯-正己烧棍合溶液(3.2.肘，在1昆匀器上充分混匀3min，于2500 r/min离心2 min，将上清液转移到另一15mL刻度试管中，残渣再分别用2mL苯-正己烧混合溶液(3.2.6)重复提取2次，合并提取液，加入1.0g无水硫酸铀(3.2.4)使之干燥。3.4.2 净化将活性碳小柱安装在固相萃取的真空抽滤装置上，用1mLX3苯先预淋洗小柱，保持流速为O.5 mL/min，弃去洗脱液。将样品提取液加到小柱上，再用1.5mLX3苯-正己皖混合溶液(3.2. 7)洗涤试管并一起转移到小柱中，收集全部洗脱
7、液。在45C下，空气流吹至近干，用正己皖榕解残渣并定容至0.50 mL，供GC/MSD分析。3.4.3 测定3.4.3.1 气相色i白质谱条件a)色谱柱:石英毛细管柱HP-5，25mXO. 2 mm(内径)，膜厚0.33m，或相当者;b)色谱柱温度:100C保持1min，以5C/min上升至200C，再以10C/min上升至280C，保持5 min; 2 c)进样口温度:280C;d)色谱-质谱接口温度:250C;e)载气:氮气，纯度二三99.995 % , 0. 6 mL/min; f)进样量:1L; g)进样方式:无分流进样，1min后开阀zh)电离方式:EI;i)电离能量:70ev; j
8、)测定方式:选择离子监测方式(SIM); k)监测离子Cm/z):177、258、344;1)溶剂延迟:20min。SN /T 1115-2002 3. 4. 3. 2 色谱测定根据样液中恶草嗣的含量情况，选定峰面积相近的标准工作溶液。标准工作榕液和样液中恶草酬的响应值均应在仪器检测的线性范围内。对标准工作液和样液等体积参插进样测定，在上述色谱条件下，恶草酣的保留时间约为25.95mino标准品SIM色谱图及全扫描质谱图见附录A中图A.1、A.2。3. 4.3.3 质谱确证对标准溶液及样液均按3.4.3.1规定的条件进行测定，如果样液中与标准搭液相同的保留时间有峰出现，则对其进行质谱确证。在上
9、述气相色谱-质谱条件下，恶草酣的保留时间约为25.95min，监测离子强度比(m/z)为258: 177 : 344= (65士10): 100 : (16土2)。3.4.4 空白实验除不加试样外，均按上述测定步骤进行。3. 5 结果计算和表述用色谱数据处理机或按下式(1)计算试样中恶草酣的含量:X=AXxV 一A, X m 式中:X试样中恶草酶的含量，mg/kg;A一一样液中恶草酣的峰面积，mm2;C.一一标准工作液中恶草酣的浓度，用/mL;A.一一标准工作液中恶草酣的峰面积，mm2;V 样液最终定容体积，mL;m一一最终样液所代表的试样量.g。注s计算结果须扣除空白值。4 测定低限、固收率
10、4.1 测定低限本方法恶草酣的测定低限分别为0.010mg/kg. 4.2 回收率4.2.1 柑桔中恶草酣添加浓度及回收率的实验数据:在0.01mg/kg时，为98.4%;在0.05mg/kg时，为100.3%; 在0.5mg/kg时，为95.0%。4.2.2 苹果中恶草酣添加浓度及回收率的实验数据:在0.01mg/kg时，为98.3%; 在0.05mg/kg时，为97.0%; 在0.5mg/kg时，为96.7%。. ( 1 ) 3 SN /T 1115-2002 附录A(资料性附录)恶草圃标准晶色谐和质糟固Abundance 25.95 nnUAUAnUAUAUnun向AU删翩翩翩翩翩翩翩刷
11、刷Eaaazaeaa。on44且i30.00 32.00 34.00 Tirne 28.00 22.00 24.00 26.00 Abundance 1000000 900000 800000 700000 600o 41 57 400000 300000 200000 100000 。50 圄A.1恶草圈标准晶的SIM色谱固258 100 150 200 固A.2恶草嗣标准晶SCAN质谱固4 302 344 287 300 358 393 408 350 400 rn/Z SN/T 1115-2002 Forword This standard was drafted in accordan
12、ce with the requirements of GB/T 1.1-20: Directives for of standardization-Part 1: Rules for the structures and drafting of standards and SN/T 01-1995 General rules for drafting the standard methods for the determination of pesticide , veterinary drug residues and biotoxins in commodities for export
13、 . The method of determination of this standard WlS drafted by referring to relevant domestic and foreign literatures through research , modification and verification .In addition , methods of sampling and sample preparation are also specified in this standard. The limit of determination is defined
14、in this standard on the basis of the current international maxi mum limits for oxadiazon residues in fruits and the sensitivity of the method. The annex A of this standard is an informative annex This standard was proposed by and is under the charge of Certification and Accreditation adminis tration
15、 of the People s Republic of China. This standard was drafted by Hunan Entry-Exit Inspection and Ouarantine Bureau of the People s Republic of China. The main drafters of this standard are Li Yongjun , Huang Zhiqiang , Xiong Fang , Zhang Ying , Dai Hua. This standard is a professional standard for e
16、ntry-exit inspection and quarantine promulgated for the first time. Note: This English version ,a translation from the Chinese text , is solely for guidance. 5 SN/T 1115-2002 Method for the determination of oxadiazon residues in fruits for import and expo同1 Scope This standard specifies the methods
17、of sampling , sample preparation and determination by gas chromatography-mass spectrometry of oxadiazon residues in fruits for import and export. This standard is applicable to the determination of oxadiazon residues in orange and apple for im p。同andexpo同.2 Sampling and sample preparation 2. 1 Inspe
18、ction lot The quantity of an inspection lot should not be more than 1 500 packages. The characteristics ofthe cargo within the same inspection lot,such as packing , mark, origin ,speci fication and grade , should be the same. 2.2 Quantity of sample taken (see Table 1) Table 1 Number of packages in e
19、ach inspection lot Minimum number of packages to be taken 1-25 26-100 5 101一25010 251-1 500 15 2.3 Sampling procedure A number of packages specified in 2.2 are taken at random and opened one b。ne.The sample taken as the primary sample from each package should be at least 500grams. The total weight o
20、f all the primary samples should not be less than 2 kg , which shall be sealed , labeled and sent to laboratory in time. 2.4 Preparation of test samples The combined primary samples is reduced to 1 kg , the edible portions are blended and then divid-6 SN/T 1115-2002 ed into two equal portions. Each
21、portion is placed in a clean container as the test sample , which is sealed and labeled. 2.5 Storage of test samples The test samples should be stored below - 18C . Note : In the course of sampling and sample preparation , precaution must be taken to avoid contamination or any factors which may caus
22、e the change of residue content. 3 Method of determination 3. 1 Principle The oxadiazon residues in the test sample are extracted with beneze- n-hexane. cleaned up by passing through a active carbon cartridge. Determination and confirmation made by means of gas chromatograph equipped with mass selec
23、tive detector, using external standard method. 3.2 Reagents and materials Unless otherwise specified , the reagents should be analtically pure , Water is redistilled water. 3.2.1 Beneze:Redistill. 3.2.2 n-Hexane:Redistilled. 3.2.3 Sodium chloride. 3.2.4 Anhydrous sodium sulfate:lgnite at 650 C for 4
24、 h , and keep in a desiccator. 3.2.5 Active carbon cartridge :SUPELCLEAN ENVI-CARB Sap-Pak cartridge , 125 mg , 3 mL or e quivalent. 3.2.6 Beneze-n-hexane solution:Beneze+ n-hexane(1 + 1). 3.2.7 Beneze-r卜hexanesolution: Beneze + n-hexane(2 + 1) . 3.2.8 Oxadiazon standard:Purity;:99%. 3.2.9 Oxadiazon
25、 standard solution: Accurately weight an adequate amount of oxadiazon stan da时，dissolvein a small volume of n-hexane. Dilute with n-hexane to form a standard stock solu tion of 1 000g/mL in concerntration. Then dilute the standard stock solution with n-hexane to the required concerntration as the st
26、andard working solution. 3.3 Apparatus and equipment 3.3.1 Gas chromatograph , equipped with mass detector. 7 SNIT 1115一20023.3.2 Solid phase extraction with mechanical vacuum pump. 3.3.3 Centrifuge:3 000 r/min. 3.3.4 Vortex mixer. 3.3.5 Centrifuge tube:15 mL. 3.3.6 Graduated tube: 15 mL. 3.3.7 Micr
27、o-syringe: 10L 3.4 Procedure 3.4.1 Extraction Weigh ca 2.0 g(accurate to 0.001 g)of the test sample into a 15 mL Centrifuge tube, add 1 9 sodi um chloride(3.2 .3) , blend for 30 s.Add 2 mL of beneze- n-hexane(3.2 .6) , blend for 3 min in vor tex mixer, centrifuge for 2 min under 2 500 r/min. Transfe
28、r the upper beneze- n-hexane extract into another 15 mL graduated tube, Repeat the procedure with 2 mL of beneze-n-hexane(3.2.6) twice, Combine beneze-n-hexane extracts ,Add 1.0 9 Anhydrous sodium sulfate(3.2.4)to dry. 3.4.2 Cleanup Set up the solid phase extraction vaccum manifold and mechanical pu
29、mp. Wash the active carbon cartridge with 1 mL x 3 beneze , keep flow speed at 0.5 mUmn. Discard the eluent. Transfer the sample residue into the cartridge. Wash the test tube with1. 5 mL x 3 beneze- n-hexane solution (3.2.7)and add into the cartridge. Collect the total eluent. and blow nearly dry w
30、ith air at 45C unit,Dissolve the residue and dilute exactly to 0.50 mL with n-hexane for GC/MSD. 3.4.3 Determination 3.4.3.1 GC/MSD operating conditions a) Column: HP-5 fused qua同zcapillary column , 25 m x 0.20 mm (id) , film thickness 0.33m，or the equivalent; b) Column temperature: 100C for 1 min ,
31、 ramp at 5C /min to 200C, ramp at 10C/min to 280 C, hold for 5 min c) Injection port temperature:280C; d) GC/MS interface temperature:250C; e) Carrier gas: Helium , purity;:,: 99.999% ,0.6 mUmin; f) Injection volume: 1L; g) Injection mode:Splitless, purge after 1 min; h) lonization mode: EI ; i) lon
32、ization energy: 70 ev; 8 SN/T 1115-2002 j) Acquistion mode: SIM ; k) Monitor ion(m/z): 177 ,258 ,344; 1) Sovlent delay:20 min; 3.4.3.2 GC/MSD determination According to the approximate concentration of oxadiazon in the test sample solution , select the standard working solution with similar peak are
33、a to that of sample solution , The responses of oxa diazon in the standard working solution and sample solution should be in the linear range of the instrumental detection. The standard working solution should be injected randomly in between the injections of sample solution of equal volume. Under t
34、he above GC/MSD conditions , the retention time of oxadiazon is about 25.95 min. For SIM chromatogram and scan mass spectrogram of the standard ,See Figure A.1、FigureA.2 in annex A. 3.4.3.3 GC/MSD confirmation According to the operating condition assigned in 3.4.3.1 , analyze the standard solution a
35、nd sam ple solution. if there is a peak appeared at the same retention time for both of the sample solution and standard working solution , the GC/MSD confirmation test should be conducted. Under the above GC/MSD operating conditions , the retention time of oxadiazon is about 25.95 min, the ratio of
36、the monitoring ions(m/z)is 258:177:344= (65 :1: 10):100:(16 :1: 2). 3.4.4 Blank test The operation of the blank test is the same as that described in the method of determination , but with omission of sample addition. 3.5 Calculation and expression of result The calculation of oxadiazon content in t
37、he sample is carried out bGC/MS data processor or ac cording to the following formula: X=A x Cs x V - As x m 、自/且，、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . where X一一一Oxadiazoncontentin the sample , mg/kg; A一一-Peakarea of oxadiazon in the sample solution , mm; Cs一-Peakarea of oxadiaz
38、on in the standard working solution , mm; As-一一Concentrationof oxadiazon in the standard working solution，g/mL; V一一-Finalvolume of sample solution , mL; m一一-Massof test sample,g. Note: The blank value should be subtracted from the above result of calculation. 4 Limit of determination and recovery 4.
39、1 Limit of determination The limit of determination of this method is 0.010 mg/kg. 9 SN/T 1115-2002 4.2 Recovery 4.2.1 According to the experimental data , the fo时ifyingconcentrations of oxadiazon in orange and its corresponding recoveries are: 0.01 mg/kg,the recovery 98.4%; 0.05 mg/kg, the recovery
40、 100.3% ; 0.5 mg/阔，therecovery 95.0% . 4.2.2 According to the experimental data , the f。此ifyingconcentrations of oxadiazon in apple and its correspondtng recoveries are: 0.01 mg/阔，therecovery 98.3%; 0.05 mg/阔，therecovery 97.0% ; 0.5 mg/阔，therecovery 96.7% . 10 Abundance 50000 45000 40000 35000 30000
41、 25000 20000 15000 10000 5000 。Abundance 1000000 900000 800000 700000 600000 400000 300000 200000 100000 。41 57 50 Annex A ( informative) SIM chromatogram and Scan mass spectrogram 。foxadiazon standard 25.95 22.00 24.00 26.00 28.00 30.00 32.00 Figure A. 1 SIM chromatogram of the oxadiazon standard 1
42、75 258 112 302 SN/T 1115-2002 34.00 Time 344 287 358 3串3408 100 150 200 300 350 400 m/Z Figure A.2 Scsn Mass sp町trogramof the oxadiazon现andardNOON的FFF同Zm中华人民共和国出入境检验检疫行业标准进出口水果中恶草嗣残留量的检验方法SN/T 1115 2002 4峰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唾开本880X12301/16 印张1字数22千字2002年9月第一版2002年9月第一次印刷印数1一20007巳铃定价10.00网址书号:155066.2-14716 版权专有侵权必究举报电话:(010)68533533
