Determination of As, Bi, Pb, Sb, Sn in copper, nickel and alloys on their base by electrothermal atomization atomic absorption spectrometry (ETAAS)

Abstract

Copper and nickel-based alloys are widely used in various industrial settings. Their properties directly depend on the impurities and alloying additives present. Therefore, monitoring of their content in the composition of alloys is still an urgent task. Analytical characteristics of the methods used for determination As, Bi, Pb, Sb, and Sn in copper, nickel, and alloys on their base are studied using electrothermal atomic absorption spectrometry (ETAAS) with selective radiation sources, deuterium background correction, longitudinally heated graphite tube, and high-resolution ETAAS with a continuous source and a transversely heated atomizer. The parameters of the temperature program of the atomizer were optimized for both version of the atomic absorption spectrometry. The revealed interfering effect of the matrix (Cu and Ni) of the studied samples significantly distorts the analytical signals of the analytes and results in significant non-selective absorption. It is shown that when constructing calibration dependencies using ETAAS with selective radiation sources, it is necessary to add a matrix component to the calibration solutions, whereas for high-resolution ETAAS it is possible to avoid introduction of the matrix component without increasing the error of analysis. The developed procedures were tested in analysis of the high-purity copper and nickel samples and standard samples of the composition of the alloys based on copper VSM14-5 (rough copper), VSM14-6 (bronze), and nickel VSN2-2. The achieved detection limits for high-resolution ETAAS with a continuous source leveled at n × 10 –5 %, whereas for low-resolution ETAAS with selective radiation sources the detection limits were higher by an order of magnitude. To determine lower concentrations of the elements in such materials, separation of the sample matrix should be used.