The suppression of some interferences in the determination of molybdenum by atomic-absorption spectroscopy in an air-acetylene flame

Abstract

Earlier published work on the determination of molybdenum with an incandescent air-acetylene flame showed that aluminium could be used effectively to suppress the interferences of such elements as strontium, calcium, manganese and iron, but this has not been confirmed for manganese and iron by other workers. Indications are that this is caused by instrumental characteristics. Ammonium chloride, subsequently shown to be effective in the suppression of manganese and iron interference in metallurgical analysis, was found to suppress the interferences of alkaline earth chlorides, but to have no effect on a severe interference by calcium ion, sulphate and phosphate in combination. As aluminium ion was found to suppress this interference, a mixture of aluminium and ammonium chlorides is suggested for general application.