Application of an inductively coupled plasma/direct reading polychromator to the multielement analysis of natural waters

The Uranium Resource Evaluation Program requires the multielement analysis of a large number of stream and ground water samples. Inductively coupled plasma-optical emission spectrometry is the most viable technique presently available to the analytical chemist to meet the sample throughput rates required by this program. A commercially available inductively coupled plasma-direct reading polychromator has been successfully implemented into the analytical portion of this program. Several modifications which were required to further automate the standard commercial instrument will be described. The problems encountered in ultratrace analysis which arise from shifts in the spectral background produced by stray light, line broadening, and radiative recombination have been adequately documented. An evaluation of the degree of compensation produced by the background correction system supplied by the instrument manufacturer is presented. Several additional problems encountered in the automated analysis of natural water samples are discussed. Effective or at least partially effective solutions to these problems are described.