Chromium Speciation Analysis by Ion Chromatography Coupled with Inductively Coupled Plasma - Optical Emission Spectroscopy

Abstract

Two methods coupling ion chromatography with inductively coupled plasma - optical emission spectroscopy (ICP-OES) were developed for the simultaneous separation and determination of Cr(III) and Cr(VI) species. In the first method, anion chromatography with sodium bicarbonate/carbonate solution as the eluent was utilized. Cr(III) species were protected from precipitation by complexation with ethylenediaminetetra-acetic acid (EDTA) prior to analysis. The detection limits were determined experimentally as 0.05 mg L-1 for both species. Most of the common cations were found to interfere with the accurate determination of Cr(III) when present in excess of 50 mg L-1. In the second method using cation chromatography, a guard column was employed in conjunction with a stepwise elution programme to elute the chromium species. The detection limits were experimentally determined as 0.1 mg L-1 for both species.

South African Journal of Chemistry Vol.57 2004: 8-14