Enhanced vaporization of volatile halide of antimony(iii) for sample introduction in atomic spectroscopy: kinetic mechanism

Abstract

The volatilization of Sb(III) with bromide could be stimulated by the presence of iodide. The mixture of halides showed a significant effect that enhanced this chemical vaporization. The kinetic mechanism was characterized and adjusted to a first order kinetic under the experimental conditions. It could be demonstrated that the vaporization took place in two different periods. The procedure was proposed to be an alternative for sample introduction and determination of antimony by inductively coupled plasma-optical emission spectrometry. Variables influencing the analytical procedure, such as concentration of sulfuric acid, bromide and iodide potassium and flow of carrier gas, were studied and optimized by experimental design. Under optimal conditions, the LD was 12 ng mL⁻¹, with 2 ng absolute LD, after injection of 130 μL of antimony solutions. The linear response range was maintained between 0.05–50.0 μg mL⁻¹. The precision of the method (RSD), for a sample injection of 1.0 μg mL⁻¹, was in the order of 4.0%. The method was relatively free of interferences with the exception of oxidant anions.