APPLICATION OF FLOW-INJECTION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY TO THE SIMULTANEOUS DETERMINATION OF ARSENIC, ANTIMONY, TIN, BISMUTH, SELENIUM AND TELLURIUM IN STEELS

Flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) was used for the simultaneous determination of arsenic, antimony, tin, bismuth, selenium and tellurium in steels from high-concentration dissolved solid solutions. To dissolve the samples a microwave digestion system was applied to minimize the sample preparation time, the amounts of reagents and the risk of contamination. Two internal standards (Be and Rh), with ionization potentials closest to the highest and the lowest potentials of the analyte elements, were used for quantitative measurements. The flow injection and inductively coupled plasma operating parameters were optimized with respect to signal peak height and peak area intensities, stability and matrix effects. The detection limits for flow injection from solutions with high concentrations of dissolved solid [0.5% m/v Fe almost-equal-to 2% Fe(NO3)3] were 4-6 times better than those for continuous-flow sample aspiration of a 0.05% Fe matrix solution [approximately 0.2% Fe(NO3)3]. The relative standard deviations of peak areas calculated from four replicate injections of a 20 mug l-1 multi-element-spiked 0.5% m/v Fe solution varied between 1.7 and 3.0%. Acid multi-element standard calibration solutions were used for the net ratio measurements. Standard reference steel materials, Series 361-365 from NIST and ECRM 088 and 097 from BAS, were analysed to demonstrate the accuracy of the proposed method.