LIQUID-CHROMATOGRAPHIC SEPARATION OF AQUEOUS SPECIES OF CR(VI) AND CR(III)

Although chromium can be present in aqueous solutions as Cr(VI) or as any of various kinetically stable forms of Cr(III), whose distribution depends on the chemical history of the aqueous sample, most chromium speciation procedures in the literature consider only Cr(VI) and Cr(II I) (as the hexaaquo species). The present paper gives examples of char acterizations involving Cr(VI) and several typical forms of Cr(III) us ing a cation-HPLC separation scheme with spectrophotometric or radiome tric detection. These results are compared with those obtained with op en column cation-exchange chromatography using radiometric detection. (C) 1997 Elsevier Science B.V.