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

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