INTER-ELEMENTAL SELECTIVITY, SPECTRA AND COMPUTER-GENERATED SPECIFICITY OF SOME MAIN-GROUP ELEMENTS IN THE FLAME PHOTOMETRIC DETECTOR

Inter-elemental selectivities (ratios of emission intensities) of some important main-group elements -B, Ge. Sn, Pb, N, P, As, Sb, S and Se- have been measured in a filter-less flame photometric detector (FPD) under one common set of conditions. In cases of unknown, unassigned or doubtful spectral distributions -e.g. from B, Pb, N and Sb- luminescences were recorded directly from the detector under analytical operating conditions. Despite the detector's dependence on broad, low-resolution spectra that frequently overlap, a computer algorithm using dual-channel data allowed specific (= infinitely selective) chromatograms to be recorded for any FPD-active element. The spectral requirements of this method, which is based on the conditional access (CONDAC) of slope ratios, were minimal: one optical filter permitted a single computer-stored run to produce several CONDAC chromatograms. Each of these was specific in the sense that it showed only the peaks of one particular element.