SYSTEMATIC STUDY OF CHROMIUM DETERMINATION IN URINE BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

The optimized measurement of Cr in urine samples using graphite furnac e atomic absorption spectrometry, with a tungsten lamp and Zeeman-effe ct background correction is described. Sample dilution and slow hot in jection were studied in an effort to improve the precision. Parameters such as detection limit (0.08 mug l-1) and precision are reported. Ba sed on this study, the Zeeman effect with slow hot injection of dilute d sample is recommended. The method was evaluated by applying the cond itions established to a certified reference urine. The method was appl ied to the determination of chromium in urine from healthy subjects an d total parenteral nutrition patients.