LINEARIZATION OF CALIBRATION CURVES OF MANGANESE, COPPER, SILVER, THALLIUM AND CHROMIUM IN ZEEMAN GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

The linearization algorithm of L'vov et al. (Spectrochim. Acta 47B, 1187 (1992)) was employed for the linearization of calibration curves of manganese, copper, silver, thallium and chromium in Zeeman graphite furnace atomic absorption spectrometry (GFAAS), under a wide range of lamp currents and slit widths. The effectiveness of the linearization algorithm depended upon the element and the experimental conditions. For copper, the linearization was successful for all slit widths (0.2-2.0 nm) and lamp currents (9-25 mA), up to the rollover point. For manganese, silver and chromium, the linearization algorithm was generally effective up to the rollover point, except at low lamp currents (5 and 10 mA for silver, 7 mA for chromium), or extremely narrow slit width (0.07 nm for manganese). For thallium, the linearization was effective only within a short range of analyte mass before the rollover point was reached. In general, the linearization technique was able to extend the linear range of the calibration curves by a factor of 3-5, except for thallium.