Influence of iron on the determination of total selenium in sewage sludge by electrothermal atomic absorption spectrometry

Abstract

The determination of total selenium by ETAAS in complex matrices such as sewage sludge has always been a challenge owing to the problems encountered with the solubilization of selenium species and the interferences observed during their determination. The use of a microwave oven in order to shorten the digestion step can lead to the solubilization of larger amounts of elements that can behave as interferents in the determination of Se by ETAAS. This study has shown the particular influence of Fe on the determination of Se by ETAAS. A correction procedure was developed and applied successfully to different digested samples of sewage sludge.