Analysis of alloy composition by X-ray fluorescence spectrometry using liquid and thin layer techniques with an internal standard

Abstract

A wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometric method for determination of high concentrations of elements (main constituents) in copper/nickel/manganese alloy samples was developed. The method uses samples taken in the form of chips that were dissolved in nitric acid and analyzed as a solution and thin layer after evaporating.The high level of uncertainty caused by sample preparation imprecision was reduced using strontium Kα line as an internal standard for all tested elements. We compared XRF calibration curves and results from samples prepared as solid materials (disks), alloy chip solutions in special cups, alloy chip solutions evaporated from filter disks, and alloy chips that had been milled with abrasive and then pelletized. The results were compared with those from standard wet titration and gravimetric methods recommended for the samples. The thin layer method was found suitable for control of alloy compositions. Sample preparation involved: preparing alloy solution 1g/100mL with 0.2g of IS, dropping 50μL of the solution onto the filter disk and evaporation The calibration curves obtained using IS were characterized with residual standard deviation 0.13–0.25% m/m (less than 1% relative) that was required for this application.