Optimization of sample injection in TS-FF-AAS for determination of trace elements

Abstract

In this work we present a proof of concept for the optimization of the analytical performance in ThermoSpray Flame Furnace Atomic Absorption Spectrometry (TS-FFAAS) by using different systems of sample injection. The influence of different operational variables was studied with emphasis on the characteristics of the ceramic capillary employed for sample introduction. The classic single hole capillary was compared to capillaries with different number of inner holes (one, four and six) and different spatial distribution. The influence on the analytical signal of a double simultaneous injection applied to different zones of the atomization furnace was also evaluated. Determination of elements with different atomization temperature (Ag, Cd and Se) was done, results shown an optimization of the figures of merit with respect to the TS-FF-AAS conventional assembly increased with the element volatility. Applications of Multi Injection (MI-TS-FF-AAS) was evaluated for determination of Cd in “yerba mate” samples; comparison of the obtained results using the proposed technique with other validated ones showed good agreement, and a reduction of amount of sample for the determination was achieved by using the multi-injection alternative. A discussion focused on the importance of an efficient sample introduction on the figures of merit attainable with TS-FFAAS and analytical applications of the technique is provided.