SPECIATION OF CHROMIUM IN AQUATIC SAMPLES BY COUPLED-COLUMN ION CHROMATOGRAPHY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A method is described that utilizes inductively coupled plasma mass sp ectrometry as an element-selective detector for coupled column ion chr omatographic determination of chromium species in aquatic samples. The coupled column system consists of a cation guard column and an anion column. Species conversion is eliminated by minimizing the sample pret reatment and by using dilute nitric acid eluents. The smallest concent ration for quantitation is 0.3 mu g/l for Cr(III) and 0.5 mu g/l for C r(VI).