A fully on-line ionic liquid-based dispersive microextraction system for trace cobalt determination in solutions for parenteral nutrition

BERTON, PAULA; WUILLOUD, RODOLFO G.

Mar del Plata

Simposio; ELEVENTH RIO SYMPOSIUM ON ATOMIC SPECTROMETRY; 2010

Universidad de Buenos Aires y Comisión Nacional de Energía Atómica

The extraordinary diversity of physical and solution properties makes ionic liquids (ILs) novel solvents of great interest for applications in separation science [1]. Due to their unique properties, such as low volatility, tunable viscosity and miscibility, and electrolytic conductivity, ILs are unique and useful for many applications in chemical analysis [2]. Moreover, they have been proposed as environmentally friendly solvents for clean processes and green chemistry, and they are good substitutes for traditional volatile and flammable organic solvents [3]. In the present work, IL-DLLME technique implemented in a flow injection system was developed for Cobalt microextraction. Cobalt was chelated with 4-(2-pyridylazo)-resorcinol (PAR) at pH 4.8 and extracted with 30 mg of tetradecyl(trihexyl)phosphonium chloride (CYPHOS IL 101). Since CYPHOS 101 IL has lower density than aqueous phases [4], on-line retention of the IL phase in a florisil-containing microcolumn made feasible its separation. Cobalt was removed from the microcolumn with acidified acetone followed by direct injection in electrothermal atomic absorption spectrometry (ETAAS) for detection. Critical parameters influencing extraction efficiency and both, micro-extraction and on-line separation processes, were investigated and optimized. The proposed method was successfully applied for Co monitoring at trace levels in parenteral solutions which typically have high salt contents, showing good linearity, sensitivity and reproducibility. 1).        Han, D., Row Ho, K., Molecules 15(4) (2010) 2405 2).        Sun, P., Armstrong, D.W., Anal. Chim. Acta 661 (1) (2010) 1 3).        Tobiszewskia, M., Mechliñskaa, A., Zygmunta, B., Namienik, J., TrAC-Trend Anal. Chem. 28(8) (2009) 943 4).        Fraser, K.J., MacFarlane, D.R., Aust. J. Chem. 62 (2009) 309