Atomic spectrometric methods (atomic absorption and inductively coupled plasma atomic emission) for the determination of aluminium at the parts per billion level in biological fluids

Abstract

A detailed re-examination of some of the more controversial statements in the literature on the determination of Al at very low levels in human body fluids by graphite furnace atomic absorption spectrometry (GFAAS) is presented. A comparative investigation has been carried out on the suitability of GFAAS, inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-AES with electrothermal vapourisation of the samples (ETV-ICP) for the determination of Al in biological fluids. Optimisation of operating conditions and comparative figures of merit obtained by each technique are given. Conventional ICP-AES offers a convenient method for routine control of Al in serum of dialysis patients. However, when concentration levels of the element in the samples are at or below 30 µg l^–1, the more sensitive technique of GFAAS is required. Studies on the coupling to the ICP of a resistively heated graphite rod for vapourisation of 5-µl volumes as a means of extending the analytical capabilities of the commercial ICP instrument are reported along with the analytical performance characteristics observed using this ETV-ICP system for the aluminium determination.