A human urine standard reference material for accurate assessment of arsenic exposure

[摘要] Arsenicisatoxicelement,andthetoxicityoftheelementisdependentonitsmolecularform.Accurateassessmentsofarsenicexposurerequirethemeasurementofacompletepanelofinorganic,organic,andmetabolitearsenicspeciesinurine,includingarsenite(As(III)),arsenate(As(V)),monomethylarsonicacid(MMA),dimethylarsinicacid(DMA),trimethylarsineoxide(TMAO),arsenobetaine(AB),andarsenocholine(AC).Acertifiedreferencematerial(CRM)containingthepanelofarsenicspeciesinurineisneededformethodvalidationandqualityassuranceofassessmentmeasurements.Untilnow,suchaCRMwasunavailable,dueinparttothedifficultyinstabilizingarsenicspecies,especiallyAs(III).Forthefirsttime,O2intheambientatmospherewasdeterminedtobetheprimarycausefortheinstabilityofAs(III)inanaqueousmatrix,andaprocedurewasdevelopedtostabilizethepanelofarsenicspeciesinadark,lowtemperature(<−70°C),andoxygen-freeenvironment.StandardReferenceMaterial®(SRM)2669arsenicspeciesinfrozenhumanurinehasbeendevelopedtomeettheneedsinarsenicexposuremeasurementsingeneralandtosupportNationalHealthandNutritionExaminationSurvey(NHANES),inparticular.SRM2669iscertifiedforeacharsenicspeciesmentionedaboveattwoconcentrationlevelsintendedtoproximatethe50thpercentileand95thpercentiledistributionintheUSpopulation(concentrationsofAs(III),As(V),AC,andTMAOintheSRMareadjustedupwardofthetargetpercentilestobeabovethemethoddetectionlimits).TheSRMwasjointlyproducedbytheNationalInstituteofStandardsandTechnology(NIST)andtheCentersforDiseaseControlandPrevention(CDC).MeasurementsleadingtothecertificationweremadecollaborativelyatNIST,CDC,andRutgers,theStateUniversityofNewJersey...

[学科分类] 分析化学