SN 1017.2-2001出口糧谷中丁胺磷殘留量檢 驗(yàn) 方 法

ISN/T1017.2—2001本標(biāo)準(zhǔn)是按照GB/T1.1—1993《標(biāo)準(zhǔn)化工作導(dǎo)則第1單元：標(biāo)準(zhǔn)的起草與表述規(guī)則第1部分：標(biāo)準(zhǔn)編寫的基本規(guī)定》及SN/T0001—1995《出口商品中農(nóng)藥、獸藥殘留量及生物毒素檢驗(yàn)方法標(biāo)準(zhǔn)編標(biāo)準(zhǔn)同時(shí)制定了抽樣和制樣方法。測(cè)定低限是根據(jù)國(guó)際上對(duì)糧谷中丁胺磷殘留量的最高限量和測(cè)定方法的靈敏度而制定的。本標(biāo)準(zhǔn)的附錄A是提示的附錄。本標(biāo)準(zhǔn)由國(guó)家認(rèn)證認(rèn)可監(jiān)督管理委員會(huì)提出并歸口。本標(biāo)準(zhǔn)起草單位：中華人民共和國(guó)浙江出入境檢驗(yàn)檢疫局。本標(biāo)準(zhǔn)首次發(fā)布。1出口糧谷中丁胺磷殘留量MethodforthedeterminationofbutamifosresiduesincerealsforexportSN/T1017.2—20011范圍本標(biāo)準(zhǔn)規(guī)定了出口糧谷中丁胺磷殘留量檢驗(yàn)的抽樣、制樣和氣相色譜測(cè)定方法。本標(biāo)準(zhǔn)適用于出口糙米中丁胺磷殘留量的檢驗(yàn)。2抽樣和制樣2.1檢驗(yàn)批以不超過(guò)4000袋(200t)為一檢驗(yàn)批。同一檢驗(yàn)批的商品應(yīng)具有相同的特征，如包裝、標(biāo)記、產(chǎn)地、規(guī)格和等級(jí)。2.2抽樣數(shù)量按式(1)計(jì)算抽取袋數(shù)a——抽樣袋數(shù)。2.3抽樣工具2.3.1單管取樣器：不銹鋼管，全長(zhǎng)55cm(包括手柄),直徑1.5cm～2.0cm,溝槽長(zhǎng)度應(yīng)超過(guò)袋對(duì)角線長(zhǎng)度的一半。2.3.2取樣鏟。2.3.3分樣板。2.3.4樣品筒(袋):可密封。2.3.5分樣布或適用鋪墊物。2.4抽樣方法2.4.1倒包抽樣從堆垛的各個(gè)部位隨機(jī)抽取2.2中規(guī)定的應(yīng)抽樣袋數(shù)的10%(每批一般不少于3袋),將袋口縫線全部拆開(kāi)，平置于分樣布或其他潔凈的鋪墊物上，雙手緊握袋底兩角，提起約成45°傾角，倒拖約1m,使袋內(nèi)貨物全部倒出。查看袋內(nèi)和袋間品質(zhì)是否均勻。確認(rèn)情況正常后，用取樣鏟隨機(jī)在各部位抽取樣品，立即將樣品倒入盛樣器內(nèi)。每袋抽取樣品數(shù)量應(yīng)基本一致。2.4.2袋內(nèi)抽樣按2.2中規(guī)定的應(yīng)抽樣袋數(shù)的90%,在堆垛四周上、中、下各層以曲線走向隨機(jī)抽取。將取樣器管槽朝下，從每袋一角依斜對(duì)角方向插入袋內(nèi)，然后將管槽旋轉(zhuǎn)朝上，抽出取樣器，立即將樣品倒入盛樣容中華人民共和國(guó)國(guó)家質(zhì)量監(jiān)督檢驗(yàn)檢疫總局2001-12-30批準(zhǔn)2002-06-01實(shí)施SN/T1017.2—20012器內(nèi)。每袋抽取樣品數(shù)量應(yīng)與2.4.1基本一致。每批樣品總量應(yīng)不少于4kg。2.4.3大樣縮分集中袋內(nèi)抽樣和倒包抽樣所取全部樣品，倒于分樣布上，用分樣板按四分法縮分出樣品不少于2kg,裝入盛樣器內(nèi)，加封后標(biāo)明標(biāo)記并及時(shí)送交實(shí)驗(yàn)室。2.5試樣制備將樣品按四分法縮分出約1kg,全部磨碎并通過(guò)20目篩，混勻后均分成兩份，分別裝入潔凈容器內(nèi)作為試樣，密封并標(biāo)明標(biāo)記。2.6試樣保存將試樣于一5C以下避光保存。3測(cè)定方法3.1方法提要試樣中丁胺磷經(jīng)丙酮、水提取，用正已烷抽提，經(jīng)弗羅里硅土柱凈化，用乙醚-正已烷(30+70)洗脫液洗脫，濃縮后定量加入正己烷，用配有氮磷檢測(cè)器的氣相色譜儀測(cè)定，外標(biāo)法定量。3.2試劑和材料除特殊另有規(guī)定外，所用試劑3.2.2氯化鈉溶液：5%,將50gmL水中。3.2.3洗脫液：正己烷-乙醚(70+30)。3.2.4無(wú)水硫酸鈉：650℃灼燒4h,置于干燥器中備用。3.2.5弗羅里硅土：60目～100目，650C豹燒4h,置于干燥器中備用。用前130C烘4h,于干燥器內(nèi)冷卻至室溫，加3%水脫活。3.2.6丁胺磷標(biāo)準(zhǔn)品：純度≥98%。3.2.7丁胺磷標(biāo)準(zhǔn)溶液：準(zhǔn)確稱取適量的丁胺磷標(biāo)準(zhǔn)品，用丙酮配成濃度為0.10mg/mL標(biāo)準(zhǔn)儲(chǔ)備溶液，根據(jù)需要再用丙酮稀釋成適當(dāng)濃度的標(biāo)準(zhǔn)工作溶液。3.3儀器和設(shè)備3.3.1氣相色譜儀：配有氮磷檢測(cè)器和毛細(xì)管不分流進(jìn)樣系統(tǒng)。3.3.2旋轉(zhuǎn)蒸發(fā)器。3.3.3弗羅里硅土凈化柱：180mm×10mm(id),內(nèi)裝約0.5cm高的脫脂棉，1cm高的無(wú)水硫酸鈉，2.0g弗羅里硅土，1cm高的無(wú)水硫酸鈉。使用前用10mL正已烷淋洗。3.3.4硫酸鈉柱：7.5cm×1.5cm(id),內(nèi)裝5cm高無(wú)水硫酸鈉。3.3.5均質(zhì)器：11000r/min～30000r/min。3.3.10微量注射器：10μL。3.4測(cè)定步驟3.4.1提取和凈化稱取10g試樣(精確到0.1g)置于100mL三角燒瓶中，加入10mL水，浸泡2h,再加入50mL丙酮，均質(zhì)2min,過(guò)濾。殘?jiān)?×10mL丙酮再提取。濾液合并于250mL分液漏斗中，加入100mL氯SN/T1017.2—20013化鈉溶液，用50mL、30mL正己烷提取。合并正己烷層，過(guò)無(wú)水硫酸鈉柱脫水，收集流出液，于45℃水浴上旋轉(zhuǎn)濃縮至近干。用2mL正己烷溶解殘?jiān)?，并將溶液轉(zhuǎn)移至層析柱內(nèi)，加40mL正己烷-乙醚(70+30)洗脫液洗脫，控制洗脫速度(約1mL/min),收集洗脫液，于45℃水浴上旋轉(zhuǎn)濃縮至近干。加5mL正己烷溶解并轉(zhuǎn)移至離心管中，供氣相色譜測(cè)定。色譜條件a)色譜柱：HP-50+,30m×0.53mm(id)×0.5μm熔融石英毛細(xì)管柱或相當(dāng)?shù)纳V柱；c)進(jìn)樣口溫度：250℃;d)檢測(cè)器溫度：280℃;e)載氣：氮?dú)?，純度?9.999%,流量5.7mL/min;f)輔助氣：氮?dú)?，流量?0mL/min;色譜測(cè)定根據(jù)樣液中丁胺磷含量的情況，選定峰面積相近的標(biāo)準(zhǔn)工作溶液。標(biāo)準(zhǔn)工作溶液和樣液中丁胺磷的響應(yīng)值均應(yīng)在儀器檢測(cè)的線性范圍內(nèi)。標(biāo)準(zhǔn)工作溶液和樣液等體積穿插進(jìn)樣測(cè)定，在上述色譜條件下，丁胺磷的保留時(shí)間約為6.2min。標(biāo)準(zhǔn)品的色譜圖見(jiàn)附錄A中圖A1。3.4.3空白試驗(yàn)除不加試樣外，均按上述操作步驟進(jìn)行。3.4.4結(jié)果計(jì)算和表述用色譜數(shù)據(jù)處理機(jī)或按式(2)計(jì)算試樣中丁胺磷的殘留含量： (2)式中：X——試樣中丁胺磷的殘留含量，mg/kg;A——樣液中丁胺磷的峰面積，mm2;A,——標(biāo)準(zhǔn)工作液中丁胺磷的峰面積，mm2;c——標(biāo)準(zhǔn)工作液中丁胺磷的濃度，μg/mL;V樣液最終定容體積，mL;m——最終樣液所代表的試樣量，g。4測(cè)定低限和回收率4.1測(cè)定低限本方法的測(cè)定低限為0.05mg/kg。4.2回收率糙米中丁胺磷添加濃度及其回收率的試驗(yàn)數(shù)據(jù)：在0.05mg/kg在0.10mg/kg在0.50mg/kg添加水平時(shí)，回收率為94.2%;添加水平時(shí)，回收率為97.8%;添加水平時(shí)，回收率為93.2%。4(提示的附錄)標(biāo)準(zhǔn)品色譜圖5ThisstandardwasdraftedinaccordancewiththerequirementsofGB/T1.1—1993“Directivesfortheworkofstandardization—Unit1:Draftingandpresentationofstandard—Part1:Generalrulesfordraftingstandards”andSN/T0001—1995“Generalrulesfordraftingthestandardmethodforthedeterminationofpesticide,veterinarydrugresiduesandbiotoxinsincommoditiesforexport".Themethodofdeterminationofthisstandardwasdraftedbyreferringtorelevantdomesticandforeignliteraturesthroughresearch,modificationandverification.Inaddition,methodsofsamplingandsamplepreparationarealsospecifiedinthisstandard.Thelimitofdeterminationinthisstandardisdefinedonthebasesofcurrentinternationalmaxi-mumlimitforbutamifosresiduesincerealsandthesensitivityofthemethod.AnnexAofthisstandardisaninformativeone.ThisstandardwasproposedbyandisunderthechargeofChinaNationalRegulatoryCommissionforCertificationandAccreditation.ThisstandardwasdraftedbyZhejiangEntry-ExitInspectionandQuarantineBureauofthePeople'sRepublicofChina.ThemaindraftersofthisstandardareZhuxiaoyu,ZhuhongandZhengziqiangThisstandardispromulgatedforthefirsttime6MethodforthedeterminationofbutamifosbutamifosresiduesincerealsforThisstandardisapplicabletothedeterminationofbutamifosresiduesinunpolishedriceforex-2SamplingandsamplepreparationEachinspectionlotshouldnotexceefication,gradeect,shouldbethesame.2.2QuantityofsampletakenThenumberofsackstobesampledshallbecalculatedaccordingtotheformula(1): (1)a—numberofsackstobetaken.Note:Ifvalueaiswithdecimal,roundoffthedecimalpart,whichisaddedasunitytotheintegralpartofa2.3Samplingtools2.3.1Metallicsampler:Stainlesssteel,length(includinghandle):55cm,diameter:1.5cm—2.0cm,groovelength:longerthanhalfofsack'sdiagonallength.2.3.2Samplingshovel.2.3.3Plateforquartering.ApprovedbyGeneralAdministrationofQualitySupervision,InspectionandQuarantineofthePeople'sRepublicofChinaon2001-12-30SN/T1017.2—200172.3.4Samplecan(sack),whichcanbesealed.2.3.5Cloth(orothersuitablematerial)sheet:Forsampledividing(quartering).2.4Samplingprocedure2.4.1SamplingbyemptyingoutDraw10%ofthenumberofsacksspecifiedin2.2(notlessthan3sacks)atanypartofthepileatrandom.Unseamandopenthesack,andlayitonacleanclothsheet(orothercleansheet).Grasptighttwocornersofthesackbottomandrasieuptoanangleof45°,tugbackwardforca1muntilallcontentofthesackisemptiedout.Checkwhetherthequalityofgoodsisuniformwithinandbetweenthesacks.Afterconfirmingthegoodsareinnormalcondition,scoopupthesamplefromdifferentpartsoftheout-pouredcontentwithashovel,andplaceinasamplecontainerprompt-ly.Thequantityofsampledrawnfromeachsackshouldbebasciallythesame.2.4.2SamplingfrominsidethesacksDrawthesamplesfrom90%ofthenumberofsacksspecifiedin2.2asfollows:Alongthesinewaveofthepile,drawsamplesfromthesacksoftheupper,middleandlowerpartsaroundpileatrandom.Insertthesampler,withitsgroovefacingdownward,diagonallyintoeachsack,thenturnthesamplerby180°,drawoutthesampler,andpromptlypourthesampleintoacontainer.Thequantityofthesampledrawnfromeachsackshallbebasicallythesemeasin2.4.1.Thetotalweightofgrosssampleofeachlotshouldbenotlessthan4kg.2.4.3ReductionofgrosssamplePourallofsamplesonacleansheet,reducetonotlessthan2kgwithaplatebyquartering.Placeinasamplecontainer,seal,labelandsendtothelaboratoryintime.2.5PreparationoftestsampleReducethesampletoca1kgbyquartering,grindthoroughlyandletpassthrougha20meshsieve,mixthoroughlyanddivideinto2equalportions.Eachportionispalceinacleancontainerasthetestsample,sealandlabel.2.6StorageoftestsampleThetestsamplesshouldbestoredbelow-5℃andkeptawayfromlight.3MethodofdeterminationThebutamifosresiduesintestsampleareextractedwithacetoneandwater,Theextractisfurtherextractedwithn-hexane,then-hexanesolutioniscleanedupbypassingthroughacolumnfilled8withfrorisil.Theanalyteiselutedwithether-n-hexane(30+70).Theeluateisconcentratedandmadeuptoadefinitevolumewithn-hexaneanddeterminationbyGC-NPDusingexternalstan-dardmethodforquantitation.3.2.1Acetone,ether,n-hexane:Redistilled.3.2.2Sodiumchloridesolution:5%,dissolve50gofsodiumchloridein1000mLwater.3.2.4Anhydroussodiumsulfate:Igniteat650℃for4h,storeinadesiccator.deactivatewith3%ofwaterbeforeuse.3.2.6Butamifosstandard:Purity≥98%.3.2.7Butamifosstandardsolution:Accuratelyweighanappropriateamountofbutamifosstan-dardanddissolveinacetonetoprepareastandardstocksolutionof0.10mDilutethestandardstocksolutionwithacetonetotherequiredconcentrationasstandardworkingsolution.3.3Apparatusandequipment3.3.1GaschromatographyequippedwithNPDandcapillarysplitlessinlet.3.3.3Cleanupcolumn:180mmx10mm(id)glasscolumn,packedwithca0.5cmheightofab-sorbentcottonatbottom,thenwith1cmheightofanhydroussodiumsulfate,2.0gflorisil,1cmheightofanhydroussodiumsulfate,elutewith10mLn-hexanebeforeuse.3.3.4Sodiumsulfatecolumn:7.5cmx1.5cm(id),packedwith5cmheightofanhydroussodi-umsulfate.3.3.5Homogenizer:11000r/min~30000r/min.3.3.6Concialflask:100mL3.3.7Separatoryfunnel:250mL.3.3.8Evaporatingflask:150mL.3.3.9Centrifugetube:10mL.3.3.10Micro-syringe:10μL.93.4.1ExtractionandcleanupWeighca10gofthetestsample(accurateto0.1g)intoa100mLconcialflask.Add10mLwater,soakfor2h,add50mLacetone,homogenizefor2min,andthenfilter,extracttwicetheresidueswith2×10mLacetone.Combinethefiltratesin250mLseparatoryfunnel.Add100mLsodiumchloridesolution,andextractwith50mLand30mLn-hexanerespectively.Combinethen-hexanelayersandletthempassthroughacolumnofanhydroussodiumsulfatefordehydration.Collettheeffluentandrotary-evaporatetoneardrynessinawaterbathat45℃,dissolvetheresiduewith2mLn-hexaneandtransfertocleanupcolumn,elutewith40mLofether-n-hexane(70+30)eluates(flowrate1mL/min)andcolletalltheeluates,rotary-evaporatetoneardrynessat45℃water-bath.Dissolvetheresuidewith5.0mLn-hexane,andthesolutionisreadyforGC/NPDanalysis.3.4.2DeterminationGC/NPDoperatingconditiona)Column:HP-50+,30m×0.53mm(id)x0.5μmcapillarycolumnoffusedsilicaorequiva-b)Columntemperature:180℃(1min)15℃/min-255℃(5min);c)Injectionporttemperature:250℃;d)Detectortemperature:280℃;e)Carriergas:Nitrogen,purity≥99.999%.Flowrate:5.7mL/min;f)Auxgas:Nitrogen,20mL/min;g)Hydrogen:3.2mL/min;i)Injectionvolume:2μL.GC/NPDdeterminationAccordingtotheconcentrationsofbutamifosinthesamplesolution,selectthestandardworkingsolutionwithsimilarthepeakareatothatofthesamplesolution.Theresponsesofbutamifosinthestandardsolutionandthesamplesolutionshouldbewithinthelinea