Showing papers by "Walter A. Aue published in 1992"
TL;DR: In this article, the authors proposed a method based on the conditional access (CONDAC) of slope ratios, which allowed a single computer-stored run to produce several CONDAC chromatograms for any FPD-active element.
26 citations
TL;DR: In this paper, the minimum detectable amounts, in mole of metal per second at an S/Np-t-p ratio of 2, were established for these elements in comparison with transition metals already known to respond in the flame photometric detector.
Abstract: After gas-chromatographic separation as volatile organometallics, some transition elements were found to respond with analytically relevant sensitivities in the flame photometric detector. Their minimum detectable amounts, in mole of metal per second at an S/Np-t-p ratio of 2, were 1 × 10−14 for nickel and 6 × 10−13 for rhenium, as well as a less sensitive 2 × 10−12 for molybdenum and 3 × 10−12 for cobalt. (When divided by 3.7, these values yield the S/σ = 3 limit of detection as recommended by IUPAC.) Calibration curves were established for these elements in comparison with transition metals already known to respond in the flame photometric detector. Their chemiluminescent spectra, together with that of chromium, were measured in the detector at analytically (as opposed to spectroscopically) optimized conditions. Atomic lines, molecular bands, and continua were all present. Also, the spectra produced by several types of carbon compounds were recorded for a definition of potential spectral interferences f...
25 citations
TL;DR: In this article, a flame photometric detector was used in single-channel and in differential dual-channel modes to characterize and control its selectivity for various transition elements against a hydrocarbon background.
Abstract: A flame photometric detector was used in single-channel and in differential dual-channel modes to characterize and control its selectivity for various transition elements against a hydrocarbon background. The experiments included gas-chromatographable compounds of Cr, Mn, Fe, Co, Ni, Ru, Re, and Os. Single-channel dispersive modes brought only modest gains in selectivity vis-a-vis the non-dispersive (no optical filter) mode. In dual-channel differential modes, however, metal–carbon selectivities could be improved by factors of one to two orders of magnitude. The highest still measurable selectivity ratios are now in excess of 107. The differential dual-channel operation of the detector also made it possible to increase the selectivity of one hetero-element vis-a-vis another; and to distinguish between two hetero-elements, by oppositely directed peaks, in a (spectrally suppressed) matrix of carbon compounds. Metal–metal selectivities could be improved by factors of one to three orders of magnitude over the...
20 citations