snt 1954-2007 进出口冰鲜肉中二氧化氯残留量的检验方法 分光光度法

'SNT1954-2007进出口冰鲜肉中二氧化氯残留量的检验方法分光光度法中华人民共和国出入境检验检疫行业标准SNjT1954-2007进出口冰鲜肉中二氧化氯残留量的检验方法分光光度法Determinationofchlorinedioxideresiduesinicedmeatforimportandexport-Spectrophotometricmethod2007-08-06发布2008-03-01实施A罕5古部九三皱电毛主j曲同时7中华人民共和国发布国家质量监督检验检症总局 ??.bzfxw4>>?中华人民共和同出人境检验检疫rr~~标准迸出口冰鲜肉中二氧化氯残留量的检验方法分光光度法S:'-I/T1954-20074幡巾因标准出版社出版北京复兴门外三里河北街16号自j，ifZ绚码:1000-Ei网址.spc.net.cn电话6852394668517548中国标准出版社秦皇岛印刷厂印刷3峰开本880X12301/16印张0.75字数16千字200ì年11月第一版20071f11月第次印刷 印数1--2000'峙书号15;:;066??2-18236定价8.00元前言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:中华人民共和国吉林出入境检验检疫局。本标准主要起草人z徐立明、周晓、陈明岩、牟峻。本标准系首次发布的出人境检验检疫行业标准。SN/T1954-2007I??.bzfxw>?进出口冰鲜肉中二氧化氯残留量的检验方法分光光度法 1范围本标准规定了冰鲜肉中二氧化氮残留量的分光光度检测方法.本标准适用于冰鲜鸡肉中二氧化氯残留量的测定。2方法提耍'采用分光光度法在552nm处测3试剂和材料3.1丙二酸。3.2乙二胶囚乙酸二纳(EDTAX.3.3无水硫酸锅。3.4氢氧化钧。3.5硫酸。3.6磷酸二氢例。3.7N，N二乙基-对苯二胶<DP3.8DPD显包邦1]:无水硫酸的3.9丙二酸溶液(10%)。3.10氢氧化创溶液:2mol/L3.11氢氧化纳溶液:0.1mol3.12硫酸溶液:1mol/L. 3.153.16贼酸押:经120'C~140'C烘干2人=91:5:4.SN/T1954-20073.17膜酸何标准储备溶液称取1.006gil电酸仰，溶解于水，转入1000mL容量瓶中，稀释至刻度，混匀。3.18俱酸梆标准使用液z移取1.0mL膜酸梆标准储备溶液至100mL容量瓶中，稀释至刻度，浓度为10.06mg/L。4仪器与设备4.1紫外分光光度计。4.2均质器。4.3高速冷冻离心机。SN/T1954-2007 4.4离心管.50mL。4.5移液管.1.0mL、2.0mL、5.0mL、10.0mLo4.6具塞比色管.50mLo5试样制备与保存5.1试样制备从所取全部样品中取出有代表性样品约1I鸣，经捣碎机充分捣碎均匀，均分成两份，分别装人洁净容器内作为试样。密封并加贴标签。5.2试样保存将试样于18l:以下冷冻保存.在抽样及制样的操作过程中，应防止样品受到污染或发生残留物含量的变化。6分析步骤6.1提取称取试样5.0g(精确至0.1g)于50mL离心管中，加入20mL磷酸盐缓冲液(3.14).提取3mioo将提取液过滤。残渣再用20mL磷酸盐缓冲液(3.14)重复提取一次，合并滤液，同时做空白试验。将滤液移至50mL离心管中，以10000r/min的转速.4l:于冷冻离心机中离心 10min，弃去油脂，以磷酸盐缓冲液(3.14)定容，供分光光度法测定。6.2测定6.2.1标准曲线的绘制向一系列50mL具塞比包管中加入0.00.0.25.0.50.1.50.2.50.5.00.10.00mL腆酸何标准使用溶液(3.18).各加人1.0g贼化何(3.15).0.5mL硫酸(3.12).混匀后静置2min，然后加入0.5mL氢氧化纳溶液(3.10).稀释至刻度oJi!IJ各管中的浓度相当于0.00.0.05.0.10.0.30.0.50.1.00.2.00mg汀，的有效氛。分别加入2.5mL磷酸盐缓冲液和1.0g显色剂(3.8).摇匀，立即在2min内用1cm比色皿在552nm处测定吸光度，绘制标准曲线。6.2.2样品中二氧化氮的测定取50mL滤液于50mL具塞比色管中，加人1mL丙二酸溶液(3.9)混合，加入1.5mL磷酸盐缓冲液和1.0gDPD显色J1'IJ(3.8)混匀。立即在2min内，用1cm比色皿在552nm处测定吸光度，根据标准曲线求出二氧化氮的浓度.6.3结果计算2 按式(1)计算试样中二氧化氮残留量:x=(c-co)0Vx1.9一ηz式中gx试样中二氧化氮残留量，单位为毫克每千克(mg/kg);c样液中二氧化氮的浓度，单位为毫克每升(mg/L);Co一一试剂空白中二氧化氮的浓度，单位为毫克每升(mg/L),V一一样液最终定容体积，单位为毫升(mL);m最终样液所代表的试样质量，单位为克(g);1.9一一二氧化氮与有效氯间的换算系数。…(1)??.bzfxw>?7测定低限、回收率7.1测定低限本方法的测定低限为0.50mg/kg. 7.2回收率冰鲜鸡肉C102的添加浓度及其回收率实验数据.一一在0.50mg/kg时，回收率为106.O%~114.0%,-一一在2.00mg/kg时，回收率为99.0%~103.0%,-一一在4.00mg/kg时，回收率为97.5%~100.5%。SN/T1954-20073SN/T1954-2007ForewordThisstandardwasproposedbyandwasunderthechargeoftheNationalRegulationCommissionforCertificationandAccreditation.ThisstandardwasdraftedbytheJilinEntry-ExitInspectionandQuarantineBureauofthePeople'5RepublicofChina. Thisstandardwasmainlydrafte~byXuliming,ZhouXiao,Chenty!ingyan,MuJun.Thisstandardwasaprofessionalsli昌市aarálδF舌白!fy-exitinspectiotiandquarantinepromulgatedforthefirsttime./;/-4而P。-/峭fy!...;~;J..] Note:ThisEnglistiversion.atranslationfromtheChinesetext.isonlyforreference??.bzfxw>?SN/T1954-2007Determinationofchlorinedioxideresidueinicedmeatforimportandexport-Spectrophotometricmethod1ScopeThisstandardspecifiesthemethodofdeterminationofchlorinedioxide(CIO,)residueinicedmeatforimportandexportbyspectrophotometry2PrinciplecontentofCIO,inicedchicken3ReagentsandmaterialsAIIthereagentsusedshouldbe 3.1Malonicacid.3.2Disodiumedetatedihydrate3.3Sodiumsulphateanhydrous3.4Sodiumhydroxide.3.5Sulphuricacid3.6Potassiumdihydrogenphosphate.3.7N,N.diethyl-p-phenylenediamine<DPDl.5SN/T1954-20073.8DPDcolorreagent:anhydroussodiumsulphate:DPD:EDTA=91:5:4.3.9Mal口nicacidaqueoussolution(10%). 3.10Sodiumhydroxideaqueoussolution:2mofiL.3.11Sodiumhydroxideaqueoussolution:0.1moi/L3.12Sulluricacidaqueoussoltuion:1mol/L.3.13Potassiumdihydrogenphosphateaqoueoussolution:0.1mol/L3.14Phosphatebullersolution(pH=6.2):combine500mL01O.1mol/LKH,PO.with81mL010.1mol/LNaOH.anddiluteto1000mL.3.15Potassiumiodide.3.16Potassiumiodate:dried2hat(120-140);(;.3.17Standardstocksolution01potassiumiodate:weigh1.0069potussiumiodate.Dissolvewithwater.Translertoone1000mL01calibratedIlask,dilutetoscalewithwater.Mixthoroughly.3.18Standardsolution01potassiumiodate:transler1.0mL01thestockstandardsolutiontoone100mLcalibratedIlask,anddilutetoscale.Theconcentration 01thisstandardsolutionis10.06mg/L.4Apparatusesandequipments4.1Ultravioletspectrophotometer.4.2Homogenizer.4.3Highspeedrelrigeratedcentriluge.4.4Centrilugetube:50mL4.5Graduatedpipettes:1.0mL,2.0mL,5.0mL,and10.0mL.4.6Stopperedcolorcomparisontubes:50mL.6??.bzfxw>?SN/T1954-2007 5Preparationandstorageoftestsample5.1PreparationoftestsampleApproximate1kgofrepresentativesampleistakenfromthewholetestsample.Grindthoroughlywithagrinder.Mixthoroughlyanddivideintotwoequalportionsastestsample.Putintocleancon.tainers.Sealandlabelthem.5.2StorageoftestsampleThetestsamplesshouldbefrozenlystoredbelow-1日;C.Certainmeasuresshouldbetakentopre.ventcontaminationofthesamplesordecompositionoftheresiduesduringthesamplepreparationprocedure.6Procedure6.1ExtractionWeigh5.0g(accuratetoO.1g)ofthetestsampleintoa50mLcentrifugetube.Add20mLofphos-phatebuffersolution(3.14)andextractfor3minandfilterthe extract.Re-extracttheresiduewith20mLphosphatebuffersolution(3.14).Combinethetwofiltrates.Meanwhiletheblanktestisrun-nln日.Transferthecombinedfiltratetoone50mLcentrifugaltubeandcentrifugeat10000r/minfor10minat4'Cinthehighspeedrefrigeratedcentrifuge.Discardoilandfat.Dilutetothescalewithphosphatebuffer(3.14)solutionforthedeterminationbythespectrophotometer.6.2Determination6.2.1DrawingthecalibrationcurveRespectivelytransferO.O.0.25.O.50.1.50.2.50.5.00.10.00mLstandardsolutionsofpotassiumiodate(3.18)into50mLstopperedcolorimetrictubes.Add1.09potassiumiodate(3.1日.0.5mLsulfuricacid(3.12)intoeachtube.Mixthoroughly.Standstillfor2min.Then.addO.5mLsodiumhydroxidesolution(3.10).Dilutetoscale.Theconcentrationsofeffectivechlorineinthetubesare0.00.0.05.0.1日.0.30.0.50.1.00.2.∞mg/L Separatelyadd2.5mLphosphatebuffersolutionand1.09colorreagent(3.8).Shakethoroughly.Using1cmcolorcomparisoncellsimmediatelymeasureabsorbanceat552nmin2min.Drawthecalibrationcurve.SN/T1954-20076.2.2DeterminationofCIQ,inthetest臼mpleMove50mLoffiltratetoone50mLofstopperedcolorimetrictube.Add1mLofmalonicacid(3.9).Mixthoroughly.Add1.5mLofphosphatebuffersolutionand1.0gofDPDcolorreagent.Mixthoroughly.Usingone1cmofcolorimetriccellimmediatelymeasuretheabsorbanceat552nmin2min.TheconcentrationofCIO,iscalculatedfromthevalueofabsorbanceaccordingtothecali-brationcurve.6.3CalculationandexpressionoftheresultCalculatethecontentofchlorinedioxideresidueinthetestsample accordingtoformula(1):c-co)??Vx1.9….(1)mwhereX一theresiduecontentofchlorinedioxideinthetestsample.mg/kg,c-theconcentrationofchlorinedioxideinthesamplesolution,mg/L,co-theconcentrationofchlorinedioxideintheblanksolution.mg/L,V一thefinalvolumeofthesamplesolution,mL,m-thecorrespondingmassofthetestsampleinthefinalsamplesolution,g,1.9-theconversioncoefficientbetweenchlorinedioxideandeffectivechlorine7Detectlimitandrecovery7.1LimitofquantificationThelimitofquantificationofthismethodis0.50mg/kg 7.2RecoveryTheexperimentaldataofthefortifiedconcentrationsofCIO,inblankfrozenandfreshchickenandtheircorrespondingrecoveriesare:SpikeO.50mgj闹，therecovery106.0%-114.0%,Spike2.00mg/阔，therecovery99.0%-103.0%,Spike4.00mg/闸，therecovery97.5%-100.5%.SN/T1954-2007书号，155066-2-18236定价8∞元'