JOURNAL of the Tunisian Chemical Society

The natural brines are aqueous solutions strongly concentrated in oceanic salts. The total content of salts can attain 350 g/L. The studied matrix is very complex; it includes a multitude of elements; among them (Mg²⁺, Ca²⁺, Na⁺, K⁺), other miners and constituents in the state of traces such as lithium and strontium. This latter has not been studied previously. Considering what precedes; it is evident that the determination of the strontium in the state of trace by flame atomic absorption spectrometry is unsettled by phenomena of interferences due to the matrix effect. In order to understand such phenomena, this work was undertaken. Thus, the investigation of these interferences is necessary. This study allowed us to identify, for each filed of concentration of disturbing elements, the nature of interference phenomena. The obtained results showed that these interferences, are mainly chemical and spectral (interferences of ionization, dissociation, volatilization and superposition of bands). We succeeded to reduce the matrix effect, by using an analysis based on the optimization of the flame and the use of spectroscopic buffer. The persistence of the difficulties caused by presence of magnesium led to study of its quasi-total elimination of the medium.

A. Boughalmi, H. Hammi, A. M’nif

Determination of trace elements, strontium, interference phenomena, brine, flame atomic absorption spectrometry

Pages 166-172