Investigations into the generation of Ag, Au, Cd, Co, Cu, Ni, Sn and Zn by vapour generation and their determination by inductively coupled plasma atomic emission spectrometry, together with a mass spectrometric study of volatile species. Determination of Ag, Au, Co, Cu, Ni and Zn in iron

Abstract

Vapour generation–inductively coupled plasma atomic emission spectrometry has been successfully extended to the determination of silver, gold, cadmium, cobalt, copper, nickel and zinc using sodium tetrahydroborate(III). Mass spectroscopic studies suggest that volatile analyte species are unstable relative to analyte atoms. Detection limits are superior to nebulization for Ag, Au, Cu and Cd, whereas for Co, Ni and Zn detection limits are slightly worse. Matrix interferences were investigated from a variety of elements, including As, Cr, Pb, Mo, Pt, Pd, Ti, Al, Ca, Mg and Sn. Memory effects were reduced by use of a rinse solution of thiourea in hydrochloric acid. Reduction of solution-based interference from iron was accomplished by the use of 2% (v/v) phosphoric acid for the determination of Ag, Au and Cu. Potassium fluoride was necessary to reduce interferences from iron in the determination of Co and Ni. The technique was applied to the determination of Ag, Au, Co, Cu and Ni in low alloy steel standard reference materials. Excellent agreement was found between experimental and certified values.