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1、DODECYLGALLATEPreparedatthe46thJECFA(1996),publishedinFNP52Add4(1996)supersedingspecificationspreparedatthe41stJECFA(1993),publishedinFNP52Add2(1993).Metalsandarsenicspecificationsrevisedatthe61stJECFA(2003).AtemporaryADIestablishedatthe41stJECFA(1993)wasdeleteda
2、tthe46thJECFA(1996)andnoADIallocated.SYNONYMSLaurylgallate,INSNo.312DEFINITIONChemicalnamesDodecylgallate,n-dodecyl(orlauryl)esterof3,4,5-trihydroxy-benzoicacid,dodecylesterofgallicacid,dodecyl3,4,5-tri-hydroxybenzoateC.A.S.number1166-52-5ChemicalformulaC19H30O5S
3、tructuralformulaFormulaweight338.45AssayNotlessthan98.5%onthedriedbasisDESCRIPTIONWhitetocreamy-whitecrystallineodourlesssolidFUNCTIONALUSESAntioxidantCHARACTERISTICSIDENTIFICATIONSolubility(Vol.4)Insolubleinwater;freelysolubleinethanolandetherMeltingrange(Vol.4)
4、95-98oafterdryingGallicacidDissolveabout0.5gofthesamplein10mlofsodiumhydroxideTSandboilfor30minundernitrogen.Maintainingastreamofnitrogen,coolthemixtureandacidifytopH2-3withsulfuricacidTS.Filtertheprecipitatethroughasinteredglasscrucible,washwithaminimumamountofw
5、aterandthendryat110ofor2h.Themeltingpointofthegallicacidsoobtainedisabout240o,withdecomposition.TLCseparationofgallateUseathin-layerplatepreparedwithsilicagelG.Prepareasamplesolutionestersbydissolving10mgofsamplein10mlethanol.PreparecontrolsolutionAbydissolving10
6、mgofdodecylgallatein10mlethanol,andcontrolsolutionBbydissolving10mgofdodecylgallateand10mgofoctylgallatein10mlethanol.Place5μlofeachsolutionontheplate.Developthechromatogramtoabout15cmfromthestartingpointusingadevelopingsolventcontaining20volumesglacialaceticacid
7、,40volumespetroleumetherand40volumestoluene.Drytheplateinair.Spraytheplatewithanindicatorsolution,containing20%w/vphosphomolybdicacidinethanoluntilayellowcolourationpersists.Examineindaylight.Afterafewminthereisaprogressivechangetobluecolouration.After5to10minexp
8、osetheplatetoammoniavapoursuntilthebackgroundiswhite.Examineindaylight.Theprincipalspotofthesamplesolutioncorrespondswiththatfordodecylgallateinthecontrolsolut
