Determination of arsenic(V) in aqueous solutions by d.c. argon plasma emission spectrometry. Interference studies

Abstract

The linear dynamic range, detection limits, accuracy and precision of the determination of As(V) in aqueous solutions by d.c. argon plasma emission spectrometry were studied at four emission lines of arsenic(V). The interference and matrix effects of eight common acids and 12 cations [(Na)(I), K(I), Mg(II), Ca(II), Al(III), Cr(III), Cr(VI), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II)] on the determination of arsenic(V) in aqueous solutions were investigated at the arsenic emission line at 193.696 nm. The linear range covered concentrations from 0.05 to 100 µg ml^–1 of As(V). The RSD increased from 0.5 to 5% when the concentration of As(V) decreased from 10 to 0.75 µg ml^–1 and from 15 to 50% in the range 0.5–0.05 µg ml^–1 of As(V). The minimum detection limit was 0.063 µg ml^–1, calculated to 3σ of ten measurements of blank, as recommended by IUPAC.