- P-ISSN 1225-0163
- E-ISSN 2288-8985
An analytical method has been developed which determines lead in steel samples by inductively coupled plasma mass spectrometry (ICP-MS) with sample introduction by the hydride generation. The lead hydride is not stable and requires and oxidant for the oxidation into metastable Pb(IV) before reduction to <TEX>$PbH_4$</TEX> with <TEX>$NaBH_4$</TEX>. A study was carried out to find and optimum lead hydride generation condition for a sample solution with more than <TEX>$1000{\mu}g/mL$</TEX> Fe matrix. <TEX>$K_2Cr_2O_7$</TEX> was found to work as an efficient oxidant when more than <TEX>$10{\mu}g/mL$</TEX> Fe matrix was present. Lactic acid was used with the oxidant as a complexing agent of the metastable Pb(IV) to enhance sensitivity. Optimum concentrations of the sample acidity, oxidant and lactic acid were different depending on the matrix concentration. The isotope dilution method was employed for the quantitation of lead. The determined Pb concentrations of the NIST steel SRM 361 and 362 were in good agreement with the certified values within the uncertainty range.