Flame-in-gas-shield miniature flame hydride atomizers for ultra trace element determination by chemical vapor generation atomic fluorescence spectrometry

Abstract

Flame-in-gas shield miniature hydride atomizers (FIGS) have been investigated and evaluated in view of their alternative use to miniature diffusion flame hydride atomizer (MDF) to determination of hydride forming elements by atomic fluorescence spectrometry (AFS). Chemical vapour generation (CVG) by aqueous phase derivatization by NaBH 4 in a continuous flow generator (CF) was employed for the generation of volatile hydrides of As, Sb, Bi, Se, Te and Sn. A dispersive AFS apparatus using electrodeless discharge lamps (EDL) as the excitation sources has been employed for both spectra acquisition and analytical determinations. The characteristics of FIGS in terms of background emission spectra, most intense AF spectral lines and limits of detection were compared with those of most popular MDF. FIGS presents a lower background emission with respect to MDF, allowing also the control of the molecular fluorescence of OH radicals in the determination of bismuth. Limits of detection for FIGS compare very well with to those obtained by MDF giving improvement factor of 5.5, 4.4, 3.6, 3.6, 0.7 an 0.5 for Bi, As, Se, Son, Te and Sb. Accuracy of FIGS has proven by determination of arsenic and antimony in seawater (NASS-5) and river water (SRLS-4) certified reference materials and bismuth in unalloyed copper (CuV 398, CuVI 399) standard reference materials by dispersive CVG-AFS.