Study of mixed-matrix effects induced by Ca and Mg in ICP-AES

The combined matrix effects produced by the simultaneous presence of C and Mg were investigated. The description was performed using a 2(2) factorial design. For B, Ba, Co, Fe, Mn, Si and Sr, the total effect is the same as t he sum of the individuals, the rest of the analytes exhibited a combined ef fect that is smaller (Cu, Cd and Ni) or bigger (Cr) than the sum of the sin gle ones. A multiple linear regression was employed to correct for matrix e ffects. The effectiveness of the method was also tested in experimental con ditions when the variation of analyte line intensities is the result of the superposition, in different degrees, of spectral interferences and matrix effects. Average deviations from the expected values in the range of 61-6% were reduced to 4.8-0.5% after the application of the correction method.