Designation:D3919−08StandardPracticeforMeasuringTraceElementsinWaterbyGraphiteFurnaceAtomicAbsorptionSpectrophotometry1ThisstandardisissuedunderthefixeddesignationD3919;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthegeneralconsiderationsforthequantitativedeterminationoftraceelementsinwaterandwastewaterbygraphitefurnaceatomicabsorptionspectropho-tometry.Furnaceatomizersareamostusefulmeansofextend-ingdetectionlimits;however,thepracticeshouldonlybeusedatconcentrationlevelsbelowtheoptimumrangeofdirectflameaspirationatomicabsorptionspectrophotometry.Be-causeofdifferencesbetweenvariousmakesandmodelsofsatisfactoryinstruments,nodetailedoperatinginstructionscanbeprovidedforeachinstrument.Instead,theanalystshouldfollowtheinstructionsprovidedbythemanufacturerofaparticularinstrument.1.2Wavelengths,estimateddetectionlimits,andoptimumconcentrationrangesaregivenintheindividualmethods.Rangesmaybeincreasedordecreasedbyvaryingthevolumeofsampleinjectedortheinstrumentalsettingsorbytheuseofasecondarywavelength.Samplescontainingconcentrationshigherthanthosegivenintheoptimumrangemaybedilutedoranalyzedbyothertechniques.1.3Thistechniqueisgenerallynotapplicabletobrinesandseawater.Specialtechniquessuchasseparationofthetraceelementsfromthesalt,carefultemperaturecontrolthroughrampingtechniques,ormatrixmodificationmaybeusefulforthesesamples.1.4Theanalystisencouragedtoconsulttheliteratureasprovidedbytheinstrumentmanufactureraswellasvarioustradejournalsandscientificpublications.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesa...
