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1、食品分析（Foodanalysis）1,theiodinevalue(iodinevalue)ofthedefinitionandsignificanceofdeterminationDefinition:iodinechlorideorbromideiodineabsorbedby100goil,convertedintoiodinegrams.Significance:theunsaturationoffattyacidsinfatsandoils.2.Samplepretreatmentoff
2、oodanalysis(dryashing,wetdigestion)It'susedtodestroyorganiccompoundsDryashingmethod:Underaerobiccondition,theorganicmatterwasdecomposedintoCO2andH2Obyhightemperaturecombustion,andtheresidualwhiteorlightgreyinorganicmatterwasash.Advantage：Thismethodbasi
3、callydoesnotaddoraddlittlereagent,sotheblankvalueislow.Becauseofthesmallashcontent,moresamplescanbeprocessed,andthemeasuredcomponentscanbeenriched.Theorganicmatterisdecomposedthoroughly,andtheoperationissimple.Shortcoming:Ittakesalongtime.2.Becauseofth
4、ehightemperature,itiseasytocausethelossofvolatileelements.(3)thecruciblehastheeffectofretentiononthetestedcomponents,whichreducesthedeterminationresultsandrecoveryrate.Wetdigestionmethod:Theuseofstrongoxidizingagents(sulfuricacid,nitricacid,perchlorica
5、cid,hydrogenperoxide,PotassiumPermanganate,etc.)heatingdigestioniscomplete,thedecompositionoforganicmatterinthesample,themeasuredelementsinionicstateexistsinsolution.Advantage：Thedecompositionrateoforganicmatterisfastandthetimeisshort.Duetothelowheatin
6、gtemperature,canreducetheemissionofvolatilemetalloss.Shortcoming:Produceharmfulgas.Itiseasytoproducealargeamountoffoamoverflowintheearlystage.Thereagentdosageislargeandtheblankvalueishigh.3.ThedefinitionofsulfuricacidsulfonationSulfuricacidsulfonationm
7、ethod(sulfonationmethod)Samplesweretreatedwithconcentratedsulfuricacid,theintroductionofpolarfunctionalgroupsSO3typicalfat,pigment,waxandotherinterferingsubstancesbecomemorepolar,solubleinwaterandacidcompoundsseparatedfromthosesolubleinorganicsolventco
8、mponenttest.Itismainlyusedforthedeterminationoforganochlorinepesticideresidues.4,foodanalysisandinspectionofthesamplecollectionrequirements,theprincipleofcorrectsampling,foodanalysisofsampleshrinkageTheprincipleofcorrectsampling(1)theco
