Determination of aluminium, barium, magnesium and manganese in tea leaf by slurry nebulization inductively coupled plasma atomic emission spectrometry

Abstract

Samples of commercially available tea were ground in an agate pestle and mortar. Particles having diameter greater than about 80 µm were removed from this initial grind material by transport of the finer material in a flow of carbon dioxide and trapping the flow in a tube cooled with liquid nitrogen. Analyses of both the initial grind and the finer material by slurry nebulization using aqueous solutions for calibration purposes, and by conventional solution nebulization after dry ashing and acid dissolution, were carried out. While the initial grind material gave results for Al, Ba, Mg and Mn which were up to 4.3% lower than those obtained when using conventional solution analysis, slurry nebulization of the finer material gave results having relative standard deviations between 0.3 and 1.8% and not significantly different (95% confidence level) from those of conventional analysis.