Abstract
A simple method was studied for simultaneous determination of 8 heavy metals (Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb) in water. Ten ml of hydrochloric acid (1+11) and 30ml of 1 % sodium sulfite solutions were added to a 500ml of sample water, containing the heavy metals (5-50μg) . After stirring the sample water for 15 min to reduce Cr (VI) and Mn (VII), 20ml of titanium sulfate solutions (100 mg-Ti/l) as coprecipitant and 10 ml of 1% ammonium chloride solutions as buffer were added to the sample water, the pH of which was then adjusted to 10. After stirring again the sample water for 60 min, 3 ml of 2% sodium diethyldithiocarbamate solutions were added to it to complete precipitation of the heavy metals. The resulting precipitate was collected onto a membrane filter paper and air-dried for the fluorescent X-ray analysis. A gold target X-ray tube was used throughout the measurement. The goniometer was scanned from 30° to 72°. Each metal was determined by measuring the peak height of Kα line excepting that the Lα line was used for lead. Recoveries of the 8 metals examined were higher than about 90%. Only cobalt (II) ion was prevented by co-existances in sea water from coprecipi tating. The linear ranges of calibration curves were 0.01 to 1.0 mg/l for the above 8 metals.
