Determination of Cr(VI) and Cr(III) species in parenteral solutions using a nanostructured material packed-microcolumn and electrothermal atomic absorption spectrometry

MONASTERIO,.; LASCALEA, G.E.,; MARTÍNEZ, L.D; WUILLOUD, R.G.

JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY

Elsevier

Año: 2009 p. 157 - 166

0946-672X

A sequentialon-linepreconcentrationandseparationsystemforCr(VI)andCr(III)speciesdeterminationwas developed inthiswork.Forthispurpose,amicrocolumnfilledwithnanostructured a-aluminawasusedforon-line retentionofCrspeciesinaflow-injectionsystem.ThemethodinvolvestheselectiveelutionofCr(VI)with concentratedammoniaandCr(III)with1molL1 nitric acidforsequentialinjectionintoanelectrothermalatomic absorptionspectrometer(ETAAS). AnalyticalparametersincludingpH,eluenttype,flowratesofsampleandeluent,interferingeffects,etc.,were optimized.ThepreconcentrationfactorsforCr(VI)andCr(III)were41and18,respectively.Thelimitofdetection (LOD)was1.9ngL1 for Cr(VI)and6.1ngL1 for Cr(III).Thecalibrationgraphwaslinearwithacorrelation coefficientof0.999.Therelativestandarddeviation(RSD)was8.6%forCr(VI)and6.1%forCr(III)(c ¼ 10 mgL1, n ¼ 10, samplevolume ¼ 25 mL).Verificationoftheaccuracywascarriedoutbyanalysisofastandardreference material(NISTSRM1643e‘‘Traceelementsinnaturalwater’’)withareportedCrcontentof20.4070.24 mgL1. UsingtheproposedmethodologythetotalCrcontent,computedassumofCr(III)andCr(VI),inthisSRMwas 20.2670.96 mgL1. ThemethodwassuccessfullyappliedtothedeterminationofCr(VI)andCr(III)speciesin parenteralsolutions.ConcentrationofCr(III)specieswasfoundtobeintherangeof0.29–3.62 mgL1, whileCr(VI) specieswasnotdetectedinthesamplesunderstudy. r 2009 ElsevierGmbH.Allrightsreserved. 1 nitric acidforsequentialinjectionintoanelectrothermalatomic absorptionspectrometer(ETAAS). AnalyticalparametersincludingpH,eluenttype,flowratesofsampleandeluent,interferingeffects,etc.,were optimized.ThepreconcentrationfactorsforCr(VI)andCr(III)were41and18,respectively.Thelimitofdetection (LOD)was1.9ngL1 for Cr(VI)and6.1ngL1 for Cr(III).Thecalibrationgraphwaslinearwithacorrelation coefficientof0.999.Therelativestandarddeviation(RSD)was8.6%forCr(VI)and6.1%forCr(III)(c ¼ 10 mgL1, n ¼ 10, samplevolume ¼ 25 mL).Verificationoftheaccuracywascarriedoutbyanalysisofastandardreference material(NISTSRM1643e‘‘Traceelementsinnaturalwater’’)withareportedCrcontentof20.4070.24 mgL1. UsingtheproposedmethodologythetotalCrcontent,computedassumofCr(III)andCr(VI),inthisSRMwas 20.2670.96 mgL1. ThemethodwassuccessfullyappliedtothedeterminationofCr(VI)andCr(III)speciesin parenteralsolutions.ConcentrationofCr(III)specieswasfoundtobeintherangeof0.29–3.62 mgL1, whileCr(VI) specieswasnotdetectedinthesamplesunderstudy. r 2009 ElsevierGmbH.Allrightsreserved.