Interference effects of some carriers on the atomic absorption of Cr, Mn, Sb, Fe, Bi, and Pb in air-acetylene flame

The effect of milligramme amounts of Zr, La, Fe as carriers used in trace analysis and the influence of Cl- and SO2-4 ions on atomic absorption of microgramme amounts of Cr, Mn, Sb, Fe, Bi and Pb were examined. It was stated that in the medium of hydrochloric acid the carriers do not affect essentially the absorbance of the studied elements. The presence of sulphuric acid, in the solution with carriers, causes chemical interferences in the flame, which are observed as suppression of absorbance for some elements. The effect of sulphate ions is very different for various compositions of the analyte. The most depressing effect which attains 50% is observed for chromium in the presence of lanthanum or iron and for manganese in the presense of zirconium. The change of flame composition and of the height of observed zone in the flame influence only the absorbance of chromium. It depends upon the processes of thermal dissociation and atomization of chromium compounds in the flame, which is connected with the composition of the analyte. (author)