Observations on the limitation imposed by interferences in flame atomic-absorption spectrometry at high analyte concentrations

Abstract

When burner rotation or an absorption line of poorer sensitivity is used in flame atomic-absorption spectrometric analysis, care must be taken to establish the absence of fresh or increased interferences at higher concentrations of the analyte element. At high concentrations, sulphate was found to cause severe depressions in the determinations of magnesium, cobalt and nickel, although under normal conditions the interference is negligible. The risk of substantial error can be reduced either by dilution of samples and standards, or by taking measurements by using the upper part of a fuel-lean flame that is burning on a slot burner with a triangular cross-section, or by adding a suitable releasing agent.