Octadecyl Bonded Silica Membrane Disk Modified with Cyanex302 for Preconcentration and Determination of Traces of Cobalt in Urine by Flame Atomic Absorption Spectrometry

Abstract

Octadecyl bonded silica membrane disk was impregnated with Cyanex302 for flame atomic absorption spectrometric determination of traces of cobalt(II) in urine. The solid phase extraction method developed using the modified disk was systematically investigated for sorption-desorption of cobalt(II). Cobalt(II) was quantitatively sorbed on the disk at pH 6.0 and eluted using 15 cm 3 of 1 Â 10 À3 M HCl. The lower limit of detection for cobalt(II) was 1.5 mg dm À3 and the preconcentration factor 133 with a precision in terms of relative standard deviation (% R. S. D.) 0.6. The reusability of the modified disk was !35 cycles.