Determination of Ca, Mg, Na, Cd, Cu, Fe, K, Li and Zn in acid mine and reference water samples by inductively coupled plasma atomic fluorescence spectrometry

Abstract

An inductively coupled plasma atomic fluorescence spectrometric (ICP-AFS) method was used for the determination of nine elements in natural water. Reference and acid mine water samples were analysed by this method to demonstrate its usefulness for hydrogeochemical exploration. The elements were determined in two groups based on the compatibility of operating conditions and consideration of element abundance levels in natural water. Ca, Mg and Na were determined as a group using one set of instrumental conditions and a 1 + 99 dilution of the sample, and Cd, Cu, Fe, K, Li and Zn were determined using another set of conditions and the undiluted sample. The detection limits for the elements are as follows: Ca, 1.4; Mg, 1.7; Na, 2.0; Cd, 1.8; Cu, 6.2; Fe, 15.8; K, 3.5; Li, 0.3; and Zn, 1.2 ng ml^–1. Each element has a linear range spanning about four orders of magnitude. The method has good precision and accuracy, as shown by statistics on replicate analyses and by the agreement between values obtained and those recommended for the reference water samples, and also those obtained by atomic absorption spectrometry for the acid mine water samples.