Abstract

A multivariate interference study was carried out using a low power inductively coupled plasma atomic emission spectrometer, after optimization of operating parameters in order to achieve both plasma robustness and maximum signal to background ratios. The method, based on the empirical modelling and experimental design concepts, provided a multivariate quantification of interferences caused by complex matrices containing Na, K, Ca, Al and Fe, at concentration levels ranging from 10 to 5000 µg ml⁻¹, deducing the complex relationships between interfering effects and matrix composition. In order to test the plasma excitation conditions, the Mg II 280.270 nm to Mg I 285.213 nm line intensity ratio was measured for each combination of matrix elements. Both Meinhard and ultrasonic nebulization were considered for comparison.