DETERMINATION OF SELENIUM AND TELLURIUM IN NICKEL AND NICKEL IRON-BASED ALLOYS BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY WITH A NICKEL PALLADIUM MATRIX MODIFIER

摘要

A nickel/palladium matrix modifier was proposed for the determination of selenium and tellurium in nickel and nickel/iron-based alloys by graphite furnace atomic absorption spectrometry without preseparation of the matrix. The effect of this matrix modifier was studied and it was found that a composition of 3000 mg/l of nickel and 100 mg/l of palladium gave the optimal effect. The interference effects of major matrix (nickel and iron) and minor matrix (chromium, cobalt, aluminium, molybdenum, titanium, niobium and tantalum) compounds were studied. Selenium and tellurium in a standard nickel/iron-based alloy and five nickel-based alloys were determined. The relative standard deviations were 4.4% for 11.0 mu g/g of selenium and 4.9% for 2.1 mu g/g of tellurium. The characteristic masses were 19 pg for selenium and 17 pg for tellurium. The recoveries of these elements were better than 85% for 10 ng/ml of selenium and 5 ng/ml of tellurium. The linearity ranges were 0-60 mu g/l for selenium (r = 0.9999) and 0-20 mu g/g for tellurium (r = 0.9993). [References: 8]