X-ray fluorescence determination of iron, copper, nickel, chromium and zinc ions in aqueous solutions in mutual presence

Abstract

A method for simultaneous X-ray fluorescence determination of iron, copper, nickel, chromium, and zinc cations in aqueous solutions is proposed. The method uses a mathematical model describing the dependence of the X-ray fluorescence intensity on the sample composition. The model included five equations with unknown concentrations of each metal – one for each characteristic wavelength. The intensity of the blank experiment, the fluorescence intensities of each metal, and the absorption of radiation by accompanying components were taken into account in the equations. The model coefficients were estimated based on the results of a type 2k full factorial experiment. The significance of the coefficient estimates and the adequacy of the model were checked. The relationship between the sensitivity coefficients in the regression equations and the molar masses of the determined metals was shown. A significant interfering influence of individual elements on the determination results of each other was established. The correctness of the analysis using the proposed method was confirmed by studying mixed model solutions and comparing the results of the galvanic effluents analysis with data from alternative methods.