Determination of Silicon by an Indirect Atomic-absorption Method Using Carbon-rod Electrothermal Atomization

Julian Tyson, University of Massachusetts Amherst
W. S. Wan Ngah, Loughborough University of Technology


An indirect procedure has been developed for the determination of trace amounts of silicon by atomic-absorption with carbon-rod electrothermal atomization. After dissolution, the silicon is extracted as silicomolybdic acid into a mixture of diethyl ether and pentan-1-ol (5+1). The co-extraction of excess of molybdate reagent is prevented by the addition of citrate, which also destroys phosphomolybdic acids. The organic layer is washed with hydrochloric acid, μl quantities are transferred to the electrochemical atomizer and the molybdenum is measured. The method has been applied to analysis of several steels.