Coprecipitation of trace elements on aluminium hydroxide was combined with energy-dispersive x-ray fluorescence for the analysis of environmental water. The parameters for the preconcentration method were studied. The optimum procedure involves addition of 1 mg of the carrier, at pH 7.3, to a 200-ml water sample. The pH was adjusted by addition of ammonia solution. Quantitative recoveries were obtained for Ti(IV), Cr(III_, As(V), Pb(II) and Th(IV). The precision was 4–6% and the detection limits were in the range 0.2–0.8 µg l-1. |