Simultaneous determination of cobalt and manganese in urine by electrothermal atomic absorption spectrometry. Method development using a simplex optimization approach

Abstract

A rapid method for the simultaneous determination of Co and Mn in urine was developed using a multielemental Perkin-Elmer SIMAA 6000 graphite furnace atomic absorption spectrophotometer. A simplex optimization was used to establish the pyrolysis and atomization temperature, and the ramp and hold time for the pyrolysis step. The sample preparation was a simple 1 + 1 dilution, using a diluent of 2% v/v HNO₃ and 0.05% m/v Triton X-100 in MilliQ-water. The LODs were 0.18 µg l^–1 for Co and 0.09 µg l^–1 for Mn. The recovery studies, to check for bias, have shown acceptable accuracy for the procedure (104% for Co and 100% for Mn, with 15 and 13% RSD, respectively; 2 µg l^–1 Co added to 10 different samples at 0.46–1.91 µg l^–1, 2 µg l^–1 Mn added to 10 different samples at 0.11–1.09 µg l^–1).