Authors: Lu Yang Elena Ciceri Zoltán Mester Ralph E Sturgeon
Publish Date: 2006/09/05
Volume: 386, Issue: 6, Pages: 1673-1680
Abstract
A method is presented for the simultaneous determination of CrIII and CrVI in yeast using speciesspecific doublespike isotope dilution SSDSID with anionexchange liquid chromatography LC separation and sector field inductively coupled plasma mass spectrometric SFICPMS detection Total Cr is quantitated using ID SFICPMS Samples were digested on a hot plate at 95±2 °C for 6 h in an alkaline solution of 05 M NaOH and 028 M Na2CO3 for the determination of CrIII and CrVI whereas microwaveassisted decomposition with HNO3 and H2O2 was used for the determination of total Cr Concentrations of 2014±16 1952±103 and 76±48 mg kg−1 one standard deviation n=4 3 3 respectively were obtained for total Cr CrIII and CrVI in the yeast sample Significant oxidation of CrIII to CrVI 242±76 CrIII oxidized n=3 and reduction of CrVI to CrIII 376±65 CrVI reduced n=3 occurred during alkaline extraction and subsequent chromatographic separation at pH 7 Despite this significant bidirectional redox transformation quantitative recoveries for both CrIII and CrVI were achieved using the SSDSID method In addition mass balance between total Cr and the sum of CrIII and CrVI concentrations was achieved Method detection limits of 03 2 and 30 mg kg−1 were obtained for total Cr CrVI and CrIII respectively based on a 02g subsample
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