On-Line Preconcentration of Zinc on Ethyl Vinyl Acetate prior to its Determination by Vapor Generation Associated to Inductively Coupled Plasma Optical Emission Spectrometry

L.A. ESCUDERO, S. CERUTTI, J.A. SALONIA, L.D. MARTINEZ, J.A. GASQUEZ

Mar del Plata

Simposio; Eleventh Rio Symposium on Atomic Spectrometry; 2010

The use of hydride generation techniques has expanded in scope to encompass the generation of  “unconventional” volatile species (possibly as hydrides, vapors, or other unidentified species) of different noble and transition metals and noble metals and noticeable efforts have been dedicated to clarification of mechanistic aspects [1, 2]. Attention has been paid to the development of vapor generation of zinc because this element plays an important role in environment and human health [3, 4]. In the present work, for first time, an on-line preconcentration procedure has been coupled to zinc vapor generation. The variables involving the preconcentration and the vapor generation were optimized using full factorial designs, respectively. Trace amounts of zinc were preconcentrated by sorption on a minicolumn packed with ethyl vinyl acetate. The analyte retained was removed from the minicolumn with hydrochloric acid. After that, volatile species of zinc were generated by merging the acidified eluent and sodium tetrahydroborate (III) in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the inlet tube of the inductively coupled plasma torch. An enhancement factor of 58-fold for a sample volume of 25 ml was obtained. The detection limit achieved was 0.06 mg L-1.The proposed method was successfully applied to the determination of traces of Zn in a CRM and water samples.