Coprecipitation of ruthenium with chitosan and its determination by graphite furnace atomic absorption spectrometry

Abstract

A coprecipitation method with chitosan was studied for the determination of ruthenium in water samples by graphite furnace atomic absorption spectrometry. Ruthenium (0.1–5.0 μg) is coprecipitated quantitatively from a aqueous sample solution (100–1000 cm 3) with chitosan at pH 7.5–8.5. After the coprecipitate was separated by centrifuging from the aqueous sample solution, it was dissolved in 1.0 cm 3 of 1.0 mol dm −3acetic acid and diluted to 5.0 cm 3 with water. An aliquot of the resulting solution was injected into the graphite furnace. The calibration graph by the proposed method was linear up to 5.0 μg dm −3, and the detection limit ( S/ N = 3) for ruthenium was 0.06 μg dm −3. The relative standard deviation at 1.0 μg dm −3 was 3.0–4.0% ( n = 5). The proposed method was applied to the determination of trace amounts of ruthenium in water samples.