Cold vapor ionic liquid-assisted headspace single-drop microextraction for mercury speciation and determination with ETAAS detection

MARTINIS, ESTEFANIA M.; ALTAMIRANO, JORGELINA C.; OLSINA, ROBERTO A.; WUILLOUD, RODOLFO G.

Mar del Plata; Argentina

Simposio; ELEVENTH RIO SYMPOSIUM ON ATOMIC SPECTROMETRY; 2010

Universidad de Buenos Aires y Comisión Nacional de Energía Atómica

Single-drop microextraction (SDME) technique has been widely used in the last years as a powerful tool for preconcentration and matrix separation of a variety of organic and inorganic compounds. However, the use of traditional organic solvent for SDME has adverse consequences, i.e. prolonged extraction time and fast stirring rate of sample solutions resulting in drop dissolution or evaporation. Consequently, and to overwhelm these drawbacks, novel solvents are currently under study. Ionic liquids (ILs) have been recently investigated as alternative solvents for SDME technique. Among other advantages, ILs have minimal or none emission of VOCs into the atmosphere. In this work, a detailed analytical study on Hg atomic vapor capture by an IL has been developed. Tetradecyl(trihexyl)phosphonium chloride CYPHOS IL 101 is proposed in combination with head space-SDME technique for separation, preconcentration, and determination of Hg species. The metal vapor was captured into a CYPHOS IL 101 microdrop followed by injection in ETAAS for elemental detection. Stannous chloride (SnCl2) was used to reduce Hg2+ to volatile Hg°, while oxidation of OrHg species allowed the determination of total Hg. Mercury was determined in different complex matrix samples like sea water, sea food hair and wine. This microextraction technique is a simple, inexpensive, effective and virtually solvent-free sample pretreatment. S. Risticevic, V. H. Niri, D. Vuckovic and J. Pawliszyn, Anal. Bioanal. Chem., 393 (2009) 781-795. L. Ji, S. W. Thiel and N. G. Pinto, Ind. Eng. Chem. Res., 47 (2008) 8396-8400. S. Gil, S. Fragueiro, I. Lavilla and C. Bendicho, Spectrochim. Acta Part B, 60 (2005) 145-150.