ISSN:
1612-1112
Keywords:
Ion Exchange Chromatography
;
Speciation of chromium
;
Chromium(III)
;
Chromium(VI)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary Chromium can be present in aqueous solution as Cr(VI) or in monomeric, dimeric, trimeric and higher polymeric forms of Cr(III). Many monomeric forms of Cr(III) are possible, with the water molecules of Cr(H2O) 6 3+ substituted by anionic or neutral species. This proliferation of Cr(III) species makes the complete speciation of chromium a continuing challenge to the analyst. A simple and effective cation exchange procedure for the separation of various of these species uses a small glass column containing 1 mL of pre-treated cation exchange resin (Na+ form). Stepwise elution with solutions of perchloric acid, Ca2+ (pH=2) and La3+ (pH=2) separates Cr(VI) and seven Cr(III) species from CrX3 to tetramer. Radiometric (Cr-51), spectrophotometric and other detection methods can be employed; the use of radiochromium gives the lowest detection limit.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02268143
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