Speeding up determinations by electrothermal atomic-absorption spectrometry

Abstract

Reductions in the analysis times required in electrothermal atomic-absorption spectrometry can be achieved by a critical examination of the function and timing of the steps in the heating programme. An examination of the temperature-time curves for heating in the drying stage showed that programmed ramp times for drying are rarely necessary. For most samples, drying can be achieved in under 10 s using temperatures of 130–140 °C with standard graphite tubes. Some analyses (lead in blood and copper in urine) have been found to work well without an ashing stage. For copper in urine, the ashing stage was shown to have no influence in reducing the background absorption or in affecting interferences. Using these techniques, programme times of around 60 s have been achieved; this includes the time for automatic sampling (29 s).