Determination of chromium in chloride-containing matrix using et AAS with Zeeman backround corrections and programmable magnetic field strength

Abstract

An effective method the electrothermal atomic absorption spectrometry (ET AAS) with transversally heated graphite atomizer (THGA), Zeeman effect background correction and Rh modifier was proposed for determination of Cr in chloride matrix. The optimisation of electrothermal program was performed with chromium solution containing 0.5% (w/v) NaCl and 10% (v/v) HNO3 that is a typical matrix of digested instant soups and supplements. The effect of modifier and its concentration on determination of chromium were tested. For each modifier used, a magnetic field strenght was also optimised. The significant dependence was observed for Pd and especially Rh. In spite of the relatively low concentration of modifiers, a high efficiency of thermal stabilization and axcellent sensitivity were obtained for Pd and Rh modifier used. The methods were recommended for the determination of chromium in digested samples containing high concentration chloride matrix e.g. instant soups and supplements.