Abstract
A simple method was developed for the direct and simultaneous determination of arsenic, manganese, cobalt, and nickel in urine by a multi-element graphite furnace atomic absorption spectrometer (Perkin-Elmer SIMAA 6000). Pd was used as the chemical modifier along with a special purge gas (5% H2+95% Ar) and a two-step ashing process. The matrix interferences were removed effectively so that a simple calibration curve method could be used (with 1:1 dilution). A standard reference material (Seronorm Trace Elements Urine) was used to find the optimal temperature program and to confirm the accuracy of the technique. The analyzed values for all these elements were within 85%-115% of certified values. The recovery (using the real urine samples) were within 80%-120% for four elements. With the ashing temperature at 1350℃, and the atomization temperature at 2100℃, the detection limits were 0.78 μg l-1 for As, 0.054 μg l-1 for Mn, 0.22 μg l-1 for Co, and 0.35 μg l-1 for Ni. The relative standard deviations (RSDs) was lower than 5%.