Adaptive Calibration in Electrothermal Atomic Absorption Spectrometry

A method is developed for determining concentrations in Zeeman electrothermal atomic absorption spectrometry based on the conversion of the transformation function of an atomic absorption spectrometer into a calibration dependence adapted to the matrix of the analyzed sample. The transformation function is expressed as a one-parameter saturation function, which is an integral optical characteristic of the spectrometer, independent of the composition of the analyzed sample. The algorithm of the method includes measurement of the analytical signals of an analyzed sample and a same sample with a known additive of the analyte and calculation of the matrix coefficient and the desired concentration of the analyte in the analyzed sample from these signals. The adaptive calibration method is tested for As, Au, Cd, Cu, Mo, Pd, Pb, Mo, Pd, Pb, Ti, V. The relative systematic error in determining the concentration of an element in the range of measuring the absorbance of atomic vapor does not exceed 10%. The analytical ranges for the elements exceed three orders of magnitude.