EVALUATION OF SPECTRAL INTERFERENCES ASSOCIATED WITH A DIRECT-CURRENT PLASMA-MULTIELEMENT ATOMIC EMISSION SPECTROMETER (DCP-MAES) SYSTEM

Spectral interferences associated with a direct current plasma combined with a 20-element, direct current reading echelle spectrometer have been characterized. The results indicate that molecular emission interferences due to entrained air are generally negligible, but the presence of high carbon concentrations may cause problems for two elements. Spectral interferences due to the presence of high concentrations (500 mg/1) of Ca, K, Mg, and Na were also studied. No problems were noted for Na or K while an interference due to atomic emission of Mg was observed. Calcium was responsible for stray light interferences due to near scatter and to reflections occurring in the secondary optics. The latter were eliminated by masking techniques and the former were compensated for via the use of a simple procedure.