Mechanisms of transition metal interferences in hydride generation atomic-absorption spectrometry. Part 3. Releasing effect of iron(III) on nickel interference on arsenic and selenium

Abstract

Iron(III) has a releasing effect on the interference due to nickel on the determination of arsenic and selenium. Together with an increase in the acid concentration of the solution for measurement, this effect can extend the range of interference-free determination for these elements by three orders of magnitude. A preferential reduction of Fe(III) to Fe(II), which inhibits the precipitation of the interfering nickel as the metal, is the proposed mechanism of reaction.