MULTIVARIATE CORRECTION OF CHEMICAL INTERFERENCES IN HYDRIDE GENERATION ATOMIC-ABSORPTION SPECTROMETRY

In hydride generation atomic absorption spectrometry, chemical interferences among hydride-forming elements lead to systematic errors in the determination of concentrations. Using the system of Se, Sb and As as an example of simultaneously occurring elements, it is shown how to remove the systematic underestimations by the use of multi-component calibration. The advantage of this approach relies on the multivariate treatment of mutual interferences. For the given problem, application of multiple linear regression turns out to be equivalent to partial least squares. Estimation of the standard error of prediction confirms the temporal stability of the model. Further, in contrast to the prediction of concentrations, an "inverse" model is established in order to attempt a description of interferences.