Assessment of a simple partial LTE model for semi-quantitative ICP-OES analysis based on one single element calibration standard

Abstract

A semi-quantitative ICP-OES analysis method for 66 elements, based on a simple pLTE collisional-radiative model and a single element calibration standard, is described. One experimentally determined temperature, calculated using the pLTE model with an experimentally measured ion/atom intensity ratio, is used to characterize the plasma in the observation volume. The pLTE temperatures determined from different elements and different ion/atom line pairs are much more similar (8100 ± 300 K) for the nine line pairs tested than temperatures based on LTE. The pLTE model is used to calculate relative sensitivities for all emission lines used. The sensitivity of only one emission line from one element is determined empirically from a single standard solution. The semi-quantitative concentration accuracy is within a factor of 3x for 85% of 227 emission lines from 66 elements studied.