Analysis of solid samples by graphite furnace atomic absorption spectrometry using Zeeman background correction

Abstract

Although graphite furnace atomic absorption spectrometry is one of the most sensitive techniques for trace element determinations, the analysis of solid materials can be challengingly difficult. As no dissolution is used, none of the sample matrix is removed before the introduction of the sample into the furnace, and this can result in severe vapour-phase interferences. Typically, quantification has been achieved by the use of standard additions or by comparison with a known reference material. Using stabilised temperature platform furnace technology and simple aqueous standards, we have determined Cr in plastic film, Pb in flexible PVC and Cu in NBS Standard Reference Material bovine liver. Agreement was obtained with the values provided by the sample suppliers. The precision was found to be about 4–6%(relative standard deviation).The solid materials analysed contained relatively high levels of analyte, requiring the use of alternative wavelengths and in two instances an increased gas flow during atomisation. The effect of gas flow on sensitivity was examined and 19 wavelengths were characterised for use with Zeeman background correction.