ETAAS determination of gallium in soils using slurry sampling

Abstract

For determining gallium in soils, suspensions were prepared by weighing 5–40 mg of sample and adding 5 ml of concentrated hydrofluoric acid, the suspensions being introduced directly into the electrothermal atomizer. A solution containing 0.5% m/v palladium was injected separately into the atomizer as the chemical modifier. A fast programme with no conventional ashing stage was used for the heating cycle. Calibration was carried out using aqueous standards. The detection limit was 0.25 µg g⁻¹. The reliability of the procedure was verified by comparing the results obtained with others based on microwave-oven sample digestion and by analyzing several certified reference materials. Relative standard deviation values of ±1.9% for a 20 ng ml⁻¹ standard solution and ±2.5% for a 0.1% m/v soil suspension were obtained.