Non-dispersive atomic fluorescence spectrometry of nanogram amounts of antimony with a hydride generation technique

Abstract

Atomic fluoreseace spectrometry (a.f.s.) with a non-dispersive system is combined with a hydride generation technique for the determination of antimony at the nanogram level. Fluorescence measurement is based on the reduction of antimony by either zinc or sodium borohydride, introduction of the stibine into the premixed argon (entrained air)-hydrogen flame, and excitation with an antimony electrodeless discharge lamp. The detection limits are 0.5 and 1.0 ng of antimony for zinc and sodium borohydride, respectively. The reagent blank for a 20-ml sample is ca. 5 ng of antimony for both reductants. Analytical working curves from peak-height or peak-area measurements are linear over ca. 4 orders of magnitude. Other hydride-forming elements and several metals, e.g. gold, nickel, palladium and platinum, interfere. The method gives satisfactory results for the determination of trace amounts of antimony in waste waters and lead.