简介:Asthekeypointinsexhormoneanalysis,samplepre-treatmenttechnologyhasattractedscientists’attentionallovertheworld,andthedevelopmenttrendofsamplepreparationforwardedtofasterandmoreefficienttechnologies.Takingeconomicandenvironmentalconcernsintoaccount,subcriticalfluidextractionasafasterandmoreefficientmethodhasstoodoutasasamplepre-treatmenttechnology.Thisnewextractiontechnologycanovercometheshortcomingsofsupercriticalfluidandachievehigherextractionefficiencyatrelativelylowpressuresandtemperatures.Inthisexperiment,asimple,sensitiveandefficientmethodhasbeendevelopedforthedeterminationofdiethylstilbestrol(DES)infishtissueusingsubcritical1,1,1,2-tetrafluoroethane(R134a)extractionincombinationwithgaschromatography-massspectrometry(GC-MS).Afterextraction,freezing-lipidfiltrationwasutilizedtoremovefattyco-extract.FurtherpurificationstepswereperformedwithC18andNH2solidphaseextraction(SPE).Finally,theanalytewasderivedbyheptafluorobutyricanhydride(HFBA),followedbyGC-MSanalysis.Responsesurfacemethodology(RSM)wasemployedtooptimizingtheextractioncondition,andtheoptimizedwasasfollows:extractionpressure,4.3MPa;extractiontemperature,26℃;amountofco-solventvolume,4.7mL.Underthiscondition,ataspikedlevelof1,5,10μgkg-1,themeanrecoveryofDESwasmorethan90%withrelativestandarddeviations(RSDs)lessthan10%.Finally,thedevelopedmethodhasbeensuccessfullyusedtoanalyzingtherealsamples.
简介:Codfishisakindofabyssalfishspecieswithagreatvalueinfoodindustry.However,theflavorofcodfish,especiallytheunpleasantodor,hascausedseriousproblemsinitsprocessing.Toaccuratelyidentifythevolatilecompoundsincodfish,acombinationofsolidphasemicro-extraction(SPME)methodandsimultaneousdistillationextraction(SDE)methodwasusedtoextractthevolatiles.Gaschromatography-massspectrometry(GC-MS)alongwithKovatsindices(KI)andauthenticstandardcompoundswereusedtoidentifythevolatiles.Theresultsshowedthatatotalof86volatilecompoundswereidentifiedincodfish,ofthem24wereextractedbySDE,69compoundsbySPME,and10compoundsbybothSDEandSPME.Seventyvolatilecompoundswerefoundtohavespecificodors,ofthem7typicalcompoundscontributedsignificantlytotheflavorofcodfish.Alcohols(i.e.,(E)-2-penten-1-oland2-octanol),esters(i.e.,ethylbutyrateandmethylgeranate),aldehydes(i.e.,2-dodecenalandpentadecanal)contributedthemosttofreshflavorwhilenitrogencompounds,sulphurcompounds,furans,aswellassomeketones(i.e.,2-hydroxy-3-pentanone)broughtunpleasantodor,suchasfishyandearthyodor.ItwasindicatedthatthecombinationofmultipleextractionmethodsandGC-MSanalysiscanenhancetheaccuracyofidentification,andprovideareferenceforthefurtherstudyonflavorofaquaticproducts.