Characterization of Arsenic by Atomic Absorption Spectroscopy in Oxy-Acetylene Flames

Abstract

This study, investigating the absorption characteristics of arsenic, included the sensitivities of the resonance lines suitable for analytical use, interferences, and the effect of solvents on absorption. Of the lines investigated, three proved to be analytically useful: 1972 Å and 3944 Å (1972 Å second order) having sensitivities of 1 ppm and 1937 Å with a sensitivity of approximately 2 ppm. Interferences from alkali, alkaline earth, and transition-metal ions as well as several common anions were investigated at these three wavelengths. It was found that organic solvent—water mixtures generally enhanced the arsenic absorption. The initial stage of the study was the establishment of optimum operating conditions through manipulation of various parameters. At 1937 Å, and to a lesser degree at 1972 Å, problems were encountered stemming from increased scattering of radiation and absorption by molecular oxygen and acetylene.