Determination of molybdenum in steel samples by ICP-AES after separation and preconcentration using nanometre-sized titanium dioxide

Abstract

A sensitive and selective method has been developed for the determination of Mo in steel samples using a nanometre-sized titanium dioxide micro-column (20 mm × 3.0 mm id) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Under the optimized conditions (pH 1.0, flow rate 1.5 mL min⁻¹), Mo was retained on the column and separated from the iron matrix, then eluted with 0.5 mol L⁻¹ NaOH and determined by ICP-AES. The adsorption capacity of nanometre TiO₂ for Mo was found to be 2.01 mg g⁻¹. The detection limit for Mo was 0.14 μg L⁻¹, with an enrichment factor of 100, and the relative standard deviation (RSD) was 1.8% (n = 11, C = 50 μg L⁻¹). The proposed method has been applied to the determination of Mo in certified reference steel samples with satisfactory results.