Determination of erbium by electrothermal atomic absorption spectrometry using a pyrolytic graphite coated graphite tube and a pyrolytic graphite coated graphite tube lined with tantalum foil, held in place by a tungsten spiral

Abstract

A new atomizer using a pyrolytic graphite coated graphite tube (PGT) lined with tantalum foil and held in place by a tungsten spiral (WTaPGT) was used for the determination of Er by electrothermal atomic absorption spectrometry (ETAAS). The application of WTaPGT and PGT for the determination of Er by peak area and peak height measurement are discussed. The characteristic masses of Er atomized in the WTaPGTs and PGTs were 13.3 and 19.4 pg, respectively, at an atomization temperature of 3000 K, which were close to the value of 17 pg measured by L'vov using a Ta platform. The acids HNO₃, HCl, H₂SO₄, and HClO₄, at concentrations of 1 mol dm^–3 and 1mg ml^–1 solutions of the chloride or nitrate salts of K, Na, Ca, Mg, Al, Fe, La, Ce and Y caused no matrix interferences. The WTaPGT atomization can be used for the direct determination of Er in 10 mg ml^–1 geochemical and water sediment samples after dissolution. The results showed good agreement with reference values. This paper shows that modern graphite furnace techniques provide the possibility of developing a standardless method for the determination of Er in varied and complex matrices with an accuracy of 10–15%.