【商检行业标准(SN)】 进出口粮谷中抑虫肼残留量测定方法 液相色谱法

中华人民共和国出入境检验检疫行业标准SN/T 1770—2006
进出口粮谷中抑虫肼残留量
测定方法
液相色谱法
Determination af tebufenozide residues in cerealsfor import and export-Liguid chromatographic method2006-04-25发布
中华人民共和国
效码黏供
国家质量监督检验检疫总局
2006-11-15 实施
中华人民共和国出人境梭验捡痰行业标准
进出口粮谷中抑虫肼残留
测定方法液相色谱法
SN/T1770 2C06
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中国标准出版社皇岛印刷厂印刷开木880×12321/16印张1字数22千字200号年8月第一版2006年8月第一次印刷印数1—2000
书号：1550582-17034
定价10.00元
本标准的附录 A 为资料帕附录。前
本标准由国家认证认可监督管理委员会提出并山口。本标准由中华人民共和国黑龙江山入境检验检疫局负贰起节。本标雄主要起草人：杨长志、康庆贺、田丰、韩广源、高剪。本标准系首次发布的出入境检验检疫行业标准。SN/T1770--2006
1范围
进出口粮谷中抑虫耕残留量
液相色谱法
测定方法
SN/T 1770—2006
本标准规定了进出口粮谷中抑虫耕残留量检验的抽样、制样和液相色谱测定方法。：本标准适用于进出口大米中抑虫肝残留量的检验。2抽样和制样
2.1检验批
以不超过2001为一检验批。
同一检验批的商品具有相同的特征，如包装，标记、产地、规格和等级等。2.2抽样数量
按式(1)计算抽样袋数：
式中：
4——拍样袋数：
N——全批袋数。
注：值整数，小数部分问崩进位为数。2.3抽样工具
2.3.1金属单管取样器：全长55cm包括手柄），直径1.5cm~~2.0cm，沟槽长度应超过袋对角线长度的一半。
2.3.2攻样铲或取样勺。
2.3.3分样板。
2.3.4盛样器：简或，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
从雄垛的各部位随机抽取2.2规定的应抽样件数的10%（每批一般不少于3袋），将袋口肇线全部拆开，平置于分样布或其他洁净的铺垫物上，双手紧握袋底两角，提起约成45\倾角，倒拖1m以.E，使袋内贷物全部倒出。检查货物的外观、气味、有无发、变质等，并查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攻样品，立即将样品间入盛样器内。每袋抽取样品数量应基本一致。
2.4.2袋内抽样
按2.2规定的应捆样件数（扣除倒包抽样袋数），在堆垛四周上，中、下各层以曲线形走问随机抽取。将取样器(2.3.1)管梳朝下，从每袋一角依斜对角力向插人袋内，然后将管梢旋转朝1:，抽出取样器，立即将样品倒入盛样容器内。每袋抽胶样品数量应与2.4.1基本一致。每批样品总量应不少于4kg。免费标准下载网bzxz
2.4.3大样缩分
合含并倒包和袋内抽样所取全部样品，倒于分样布上，用分样板按四分法缩分样品至不少丁2kg，倒1
SN/T 1770—2006
人盛样器内,加村后标明标记,并及时送交实验室，2.5试样制备
将样品按四分法缩分至1kg+全部磨碎并通过20日筛，混句，均分成脚份作为试样。分别装入挡净的容器内、密封，标期标记。在抽样和制样过程中，应防止样品受到污染或发生残留物含最的变化。2.6试样保存
将试样于 0℃～4℃保存。
3测定方法
3. 1 方法提要
样中残留的抑虫用丙酮-水提取后，再用二氯甲烷萃瑕,萃取液经中性氧化铝和硅胶杜挣化,浓缩、定容后，用配有紫外椅测器的液相色谱仪进行测定,外标法定。3.2试剂与材料
除另有现定外，所用试剂均为分析纯,水为去离子水，3.2. 1
甲醇：色谱纯。
3.2.2乙：色谱纯。
3.2.3丙酮。
二氯甲烷：色纯。
3.2.5止已烷：色谱纯。
3.2.6无水硫酸钠，经650℃灼烧4h,置于干燥器内备用3.2.7中性氧化铅，层板用.100目～200日，300℃灼烧4h，置于于燥器内备用。3.2.8硅胶：层析用，60归~100日，110℃烘2h，置于下燥器内备用，.3.2.9抑出耕标准品，纯度98%。3.2.10抑虫胖标准溶液：准确称取适量的抑虫耕标准品·用乙睛配成浓度为100Fg/mL的标准储备液。根据需要用流动相稀释成适当浓度的标泄工作液。3.3仪器与设备
液相色谱仪;配有紫外检测器。
粉碎机。
振荡器。
旋转蒸发器：配100ml、250mlL浓缩瓶氮吹，
其塞维形瓶：250 mL
分液漏斗250mL
滤膜：0.45um。
3. 3.9层析柱:25 cm×2.0 cm(内轻)玻璃柱，柱底填入少量脱脂棉,按2 g无水硫酸钠、1.0 g残胶、Gi g中性氧化铝、1g无水硫酸钠的顺序依次装柱。使用前用20 nL.两酮十正已烷(1+9)预淋洗。3.3.10无水硫酸钠柱：8.0cm×1.5cm(内径)玻璃柱,内装5cm高无水硫酸钠。3.4测定步骤
3.4.1提取
称试样约20g（精确到0.1g)于250ml.具形瓶，加入100ml丙酮十水（80+20），在振荡器上振荡提取 30 min,过滤于 250 L浓缩瓶中。用 30 ml. 内酮洗涤锥形瓶丁同一浓缩版中,在 45℃水浴中用旋转蒸发器浓缩至约20mL。将浓缩液转移到250mL分液漏斗中，再用60mL水洗涤，合并于同一分液端斗中，加人2×50rnL二氯甲烷充分振拯萃取2min，静置分层。将二氯甲烧层道过无水硫酸钠柱(3.3.10)脱水手250mL浓缩瓶中，在45℃水浴中用旋转蒸发器涨缩至近下，币用氮气流吹2
干，用4mL丙酮一正已烷(119）溶解残。SN/T 1770—2006
3.4.2净化
将上述溶液移人层析（3.3.9)中，用20mL丙酮十止已烷（1+9)洗涤浓缩瓶：待液面降至无水硫酸钠表面时，加入柱内淋洗，弃去流出液。用20mL丙阐十正已烷（1十1)洗脱，收集全部洗脱波于100mL浓缩瓶中，在45℃水浴中用旋转蒸发器浓缩至近干，用氮气流吹干。准确加入1.0mL流动相(3.41.3.1)溶解残渣，经0.45m滤膜过滤后供液相色谱测定，3.4.3测定
3.4.3. 1液相色谱条件
色谱：Nuclebsil1005Cs，250mm×4.0mm，5μm或当者a)
流动相：乙睛-水（55+45.V/V）：h)
流速:1.0 mL/min;
柱温：40℃；
检测波长：234III;
f）进样量：20μL。
3.4.3.2液相色谱测定
根据样液中抑业朋残留量情况，选定浓度相近的标准工作溶液，标准工作溶液和样液中抑虫耕响应值均应在器检测线性范围内。对标准工作溶液和样液等体积参插进样进行测定。在上述色谱条件下，抑虫胖的保留吋间约为11.2rnin。标准品色谱图参见附录A3.4.4空白试验
除不加试样外，均按上述步骤进行。3.5结果计算和表述
用色谱数据处理机或按式(2)计算试样中抑虫肼残留景，计算结果应将空值扣除。FXGXV
式中：
试样中抑虫肼的残留量，单位为毫克每千克(m乌/kg)：-—样波中抑虫肼的峰高,单位为毫米(mm)；hs-标雅工作溶液中抑虫耕的峰高，单位为旁米(mm)；-标准工作溶液中抑虫肼的浓度，单位为微克每毫升（/)；V：一样液最终定容体积,单位为毫升(mj.)#m
最终样液所代表的试样质量，单位为克（g）。4测定低限，回收率
4.1测定低限
本方法的测定低限为Q.0251ng/kg4.2回收率
样品中抑虫肼的添加浓度及回收率的实验数据：在0.500mg/kg时，回收率为9-.8%；一在0.050mg/kg时，回收率为87.0%+一在0.025tmg/kg时，回收率为85.6%。（2)
SN/T1770—2006
附录A
(资料性附录）
标准品色谱图
图A.1抑虫肼标准品液相色谱图
Foreword
Annex A of this standard is an infomatlve one.SN/T1770—2006
This standard was proposed by and is under the charge of National Regulatory Commission for Certi-fication and Accreditation Adrninistration of the People's Republic of China.This standard was drafted by Heilongjiang Entry-Exit Inspection and Quarantina Bureau of thePeople'sRepublic of China.
The main drafters of this standard are Yang changzhi, Kang qinghe, tian feng and Han guangyuan,Gaoyong.
This standard is an Inspection and Quarantine professional standard promulgated for the firsttime. 1
1) Note;This English Version,a translatlon from the Chinese text, is solely for guidanca.SN/T 17702006
Determination of tebufenozide residues in cerealsfor import and export-Liquid chromatographic method1Scope
This standard specifies the method of sampling, sample preparation and determinatian of tebufeno-zide residuesby liquid chromatography-in cereals for import and export.This standard is applicable to the inspection af,tebufenozide residues in rice for import and export.2
Sampling and sample preparation2.1 Inspection lot
Each inspection lot shouid not exceed 2oo t.The characteristics f the cargo within the same inspectiorn lot, such as packing, mark, rigin, spec-Ification, grade ect. , should be the same.2.2Quantityofsampletake
sampled shallbecalculatedaccordingtothe.formula(1)The number of bags to be
-number of bags
-total number of
fo betaken;
bags in a lot.
Note, if valte a is with de
ecimal,round offthedecir
2. 3 Sarmpling tools
rt,whieh
inity to the Integral part of aLength (including handle): 55 cm; diameter:1. 5 cm~ 2. 0 cm; groove2.3.1 Metallic sampler:
lengthe longer than half the diagonal langth of the bag.Samplingshovel orladle.
2. 3. 3Piate for quartering.2, 3. 4 Sample container: Can or bag. which can be sealed.2.3.5Cloth (or other suitable material) sheet:For sample dividing(quartering),2.4 Sampling procedure
2.4. 1Sampling by emptying autSN/T 1770—2006
Draw 10 percent of the ntumber of bags specified in 2.2 (not less than 3 bags) at any part of the pileat random. Unseam and sopen the bag, ard lay it on a clean cloth sheet (or other clean sheet). Grasptight two corners of the bag bottom and raise up to an angle of 45', tug backward for ca. 1 m until allcontent of the bag is ermiptied out, Check whether the quiality of goods is uniform within and betweenthe bags, After confirming the goods are in normar'condition, scoop up the sample with a shovelfrom different parts of the out-poured content at random, and promptly place in a sample container.The quantity of the sample drawn from,each bag should be basically the same.2. 4. 2 Sarnpling from inside th bagsDraw thesamples from:thenumberof bags-specified-in2.2-(by deducting thenumberof bags drawnjong the sine wave of the pile, draw the samples from the bags of the upper,in 2.4. 1) as follows: A
middle and lower parts around the pile at random, Insert the metatic sarmpler (2. 3. 1), with itsgroove facing dawnwardl,diagorally.jinto.each bag, then turn the sampler 18o°, draw out the samplerand promptly pour the sample into a contalner. The quantity of sample drawn fromt each bags shouldbe basically the same as in 2. 4. 1.The total weight of the sample of each lot should be rot less than 4 kg.2. 4. 3 Reduction of gros
Gample
Pour all the sarmples (frbm both 2.4. land 2, 4. 2) on a clean sheet. Reduce to not less than 2 kg with :plate by cuartering. Plage in a sample container. seal, label and send to the laboratory in time.2. 5 Preparation of test sampleGrind with a grinder to'tet all pass through a 20-mesh sieve. Mix'thoroughly and divide into two equalportions as the samples, Place in a clean sample containers seat and label. In the course of samplingand sample preparation.
recaution should be taken to avold contamination or any factors that maycause change of the residue content.2. 6 Storage of test sample
Thetestsampleshouldbestored oc4cSN/T1770--2006
Method of determination
3.1 Principle
The tebufenozide residues in the test sample are extracted with acetone-water. The extract is ex-tracted with dichloromethane, and clean up with an alumina and a silic gel column. The elutes solutionis evaporated. The rasidues is dissoived with acetonitrile-water and determined by HPLc With Uy. detector, us ing extermal standard method.3.2 Reagents and materials
Unless otherwise specified, all regents areanalytically pure,\wWater\is redistilled water.3.2. 1 Methanal; LC grade,
3.2.2 Acetonitrile, LC grade.3.2,.3
3.2. 4 Dichloromethane: LC grade.3.2, 5 N-hexane, LC grade.
3.2.6Anhydrous sodiurn sulfate: Ignite at 65o c for 4 h and store in a desiccator.3.2.7 Neutral alumina: For chromatography, 100 mesh 200 mesh, lgnite at 300 C tar 4 h andstore in a desiccator.
3. 2. 8 Silica gel: Far chromatography, 60 mesh~100 mesh, Heat at 110' for 2 h and store in adesiccator.
3.2.9 Tebufenozide standard:Purity98%3. 2. 10 Tebufenozide standard solution: Accurately weigh an adeguate amount of tebufenozidestandard, dissolve in acetonitrile and prepare a solution of 100 μg /mL as the standard stock solu- tion. According to the requirement, dilute a standard working sotution of appropriate concentrationwith mobile phase.
3.3Apparatusandequipment
3.3.1High performance liquid chromatograph equipped with UV-detector.3. 3.2 Grinder.
3.3. 3Shaker.
3.3.4Rotaryevaporatorwith100mL,250mLevaporatedflask3.3.5Nitrogen evaporator.
3.3.6Conicalflask：250mLwithstopper.3. 3.7 Separator funnel: 250 mL.3.3.8Membrane filter:0.45 μm.SN/T 1770—2006
3.3. 9 Chromatographic column; 25 cm × 2, 0 cm (i. d. ) Glass column, pack with a little degreasedcotton at the bottom of colurmn and add in sequence 2 g of anhydrous sodium sulfate, 1 g of silicagel. 6 g of neutral alumina, 4 g of anhydrous sodium sulfate, Pre-rinse the column with 20 mL of acetone-n-hexane (1+ 9) before use.3. 3. 10 Column of anhydrous sodium sulfate: 8. 0 cm × 1, 5 cm(i. d).packed with 5 cm height of an-hydrous sodium suifate.
3.4Procedure
3.4.1Extraction
Weigh 20 g (accurate to 0.1 g) of the test sample into a 250 mL conical flask , add 100 mL of ace-tone-water (80 + 20), and shake for 30 min with a shaker. Filter the extract into a 250 mL evaporatedflask. Wash conical flask into the same a 250 mL evaporated flask with acetone. Evaporate the extractca. 20 mt with rotary evaporator in a water-bath below 45 'C. Transfer the extract and wash evap0-rated flask with 60 mL water into a 250 mL separatar funnet. To the separator funnel, add 2 × 50 rmLof dichlorornethane, then shake violently for 2 min and let stand to separate clearly. Pass the dichloromethane layer through an anhydrous sodium sulfate colurmn (3.3.10) to remove the water, letdrain inta a 250 ml evaparated flask, Evaporate the dehydrate dichloromethane to near dryness with rotary evaporator in a water-bath belaw 45 C , then blaw to dryness under a nitrogen flow. Dissolvetheresiduebyadding 4mL ofacetone-n-hexane(1+9).3.4.2 Clean up
Rinse the above solution into the chrormatographic column (3.3.9). Wash the evaporated flask with20 mL of acetone-n-hexane (1+9)into the columin,when the liguid level lowers to the upper surfaceof anhydrous sodium sulfate,then discard the effluent. Elute with 20 mL of acetone-n-hexane (1+1)and collect all the eluate in a 100 ml evaporated flask, Evaporate the eluate to near dryness with ro-
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