Abstract

A novel method for the separation and preconcentration of chromium speciation with chitosan and determination by graphite furnace atomic spectrometry (GFAAS) has been developed. Adsorption rates of chitosan for Cr^VI and Cr^III were 98 and 20% at pH 3, respectively. Cr^VI was selectively eluted off from chitosan with 5 ml of 0.1 mol L⁻¹ sodium hydroxide and determined by GFAAS. Accordingly, contents of Cr^III were obtained by the determination of total chromium after Cr^III in water samples had been transformed into Cr^VI. The detection limit (3σ, n = 10) for Cr^VI was 0.0468 µg L⁻¹ and the relative standard deviation less than 7.8% at the 0.2 µg L⁻¹ level. The method was applied to environmental water samples with recoveries of between 92–105%.