Spectral interferences in the determination of trace elements in environmental materials by inductively coupled plasma atomic emission spectrometry

This paper deals with spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES) encountered with environmental materials. These samples normally contain high concentrations of aluminium, calcium, magnesium, iron, titanium, potassium and sodium. The investigations cover: (a) spectral data for Al, Ca, Mg, Fe, Ti, K and Na as interferents for 200 pm wide windows centred (+/-100 pm) around the prominent lines of As, B, Ba, Be, Cd, Cr, Cu, Hg, Mn, P, Pb, Sb, Se, Sn, Tl, U and Zn; (b) a data base of Q-values for line interference [Q(Ij)(lambda(a))] and Q-values for wing background interference [Q(Wj)(Delta lambda(a))] for two values of the excitation temperature 6200 K and 7200 K. The lines free or negligibly influenced by line interference were selected for analyte determination, Q-values were used for calculation of correction factors under a spectral line without the measurement of a reference blank at the wavelength of the prominent analysis lines. The accuracy of ICP-AES with the Q-concept as a basic methodology is checked by the analysis of a certified reference material IAEA/Sediment SD-N-1/2/. The precision of the method is characterised by an RSD of 0.6-1.7%. Extraction of trace elements soluble in aqua regia was used as a decomposition method. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta, Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains the tabular material of this article in electronic form. (C) 1999 Elsevier Science B.V. All rights reserved.