Determination of antimony species with fluoride as modifier and flow injection hydride generation inductively-coupled plasma emission spectrometry Original Research Article

A new method for the determination of species of antimony(III) [Sb(III)], antimony(V) [Sb(V)] and trimethylstiboxide [TMeSbO] with fluoride as modifier is introduced. A flow injection (FI) system for hydride generation was used in combination with an inductively-coupled plasma atomic emission spectrometer as detector. The pre-reduction was accomplished with potassium iodide dissolved in hydrochloric acid and the reduction with sodium borohydride. The influence of fluoride on the reduction and pre-reduction step was investigated by adding different amounts of sodium fluoride to the solvent stream. At a concentration of 100 mg/l fluoride and 1.2% potassium iodide, the hydride formation of Sb(V) and Sb(III) was suppressed below the detection limit, while TMeSbO showed no signal depression. The use of 100 mg/l fluoride without potassium iodide led to complete signal suppression for Sb(V) with apparently no influence on the signal intensity of Sb(III) and TMeSbO. The concentration of TMeSbO was measured directly, the concentrations of Sb(III) and Sb(V) were calculated on the basis of the three analyzing steps, giving detection limits and relative standard deviations of 1.1 (2.6%), 1.2 (5.3%) and 1.4 μg/l (8.1%), respectively. The method was applied to orange juice samples.