DETERMINATION OF CHROMIUM IN SERUM AND LAKE WATER BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY USING VANADIUM AND MOLYBDENUM MODIFIER

A rapid and direct method is described for the determination of chromium in serum and lake water samples with high salinities using electrothermal atomic absorption spectrometry with vanadium(v), 20 mug, and vanadium(V) plus molybdenum(VI), 20 mug of each, as chemical modifiers. The results show superior performance of these modifiers over the other types of modifier used. Recoveries of chromium from spiked samples with different matrices ranged from 97 to 104%. The precision of the determination calculated on ten replicate analyses of each sample and expressed as relative standard deviation was better than 4% for all samples. The limit of detection was 0.2 mug l-1 and the calibration graphs were linear up to 100 mug l-1. The results indicate that the life of the graphite atomizer and the rate of atomization of chromium are also increased in the presence of vanadium based modifiers.