Critical assessment of hexavalent chromium species from different solid environmental, industrial and food matrices

The accurate determination of Cr(VI), the most hazardous form of chromium, is an analytical challenge because of its facility to be reduced during all steps of the analytical procedure. This review presents a synthesis of the available studies for the analysis of Cr species in different solid samples (soils/wastes, working atmosphere, industrial and food samples). A particular attention has been paid on Cr(III) and Cr(VI) interconversions that can occur during extraction and efforts made to avoid these reactions. Although the use of NaOH/Na2CO3 solutions with heating at 90-95°C is the more widespread procedure, species transformation can still occur and several studies suggest that speciated isotope dilution (SID) could be a suitable tool for correction of these interconversions.