Chromium speciation by a surfactant-coated alumina microcolumn using electrothermal atomic absorption spectrometry

• Published in: Talanta (Oxford) 1995-08, Vol.42 (8), p.1151-1155
• Main Authors: Manzoori, Jamshid L., Sorouraddin, Mohammad H., Shemirani, Farzaneh
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Spectrometric and optical methods
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/0039-9140(95)01556-Q

A simple and convenient method has been developed for the speciation of chromium(III) and chromium(VI) in aqueous solutions using a sodium dodecyl sulphate coated alumina micro-column (1.5 cm × 5 mm i.d.) and graphite furnace-atomic absorption spectrometry (GF-AAS). Under the optimized conditions (pH 0.6, adjusted with hydrochloric acid; flow rate, 1 ml min −1) chromium(VI) is retained on the column and chromium(III) is collected and determined by GF-AAS. Total chromium is directly determined by GF-AAS and chromium(VI) is calculated by difference. The relative standard deviations (10 replicate analyses) at the 20 μg l −1 level for chromium(III) and chromium(VI) and at the 40 μg l −1 level for total chromium were 1.4%, 3.6% and 1.8%, and the corresponding limits of detection (based on 3σ) were 0.57 μg ml −1, 0.61 μg ml −1 and 0.35 μg l −1 respectively. No large interference effects have been observed from other investigated species and the method has been successfully applied to a range of water samples.