Matrix effects of potassium chloride and phosphoric acid in argon inductively coupled plasma atomic emission spectrometry

Abstract

Changes in analyte emission intensity in the presence of low concentrations of potassium chloride and phosphoric acid were studied in inductively coupled plasma atomic emission spectrometry. It has been shown that both matrices can cause significant depressant effects on the relative emission intensities of Sr, Mg, Mn, Fe, Cu and Zn under normal analytical operating conditions and that the lowering of intensity was more pronounced for KCl than for H₃PO₄ at the same analyte to matrix concentration ratio. The matrix effects can be corrected by increasing the power supplied to the plasma, which was found to correlate with the excitation energy of the emission line.