INVESTIGADORES
WUILLOUD Rodolfo German
artículos
Título:
Dispersive liquid-liquid microextraction and preconcentration of thallium species in water samples by two ionic liquids applied as ion-pairing reagent and extractant phase
Autor/es:
ESCUDERO, LETICIA B.; BERTON, PAULA; MARTINIS, ESTEFANIA M.; OLSINA, ROBERTO A.; WUILLOUD, RODOLFO G.
Revista:
TALANTA
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2012 vol. 88 p. 277 - 283
ISSN:
0039-9140
Resumen:
In the present work, a simple and highly sensitive analytical methodology for determination of Tl+ and Tl3+ species, based on the use of modern and non-volatile solvents, such as ionic liquids (ILs), was developed. Initially, Tl+
was complexed by iodide ion at pH 1 in diluted sulfuric acid solution.
Then, tetradecyl(trihexyl)phosphonium chloride ionic liquid (CYPHOS®
IL 101) was used as ion-pairing reagent and a dispersive liquidliquid
microextraction (DLLME) procedure was developed by dispersing 60 mg of
1-hexyl-3-methylimidazolium hexafluorophosphate [C6mim][PF6]
with 500 μL of ethanol in the aqueous solution. After the
microextraction procedure was finished, the final IL phase was
solubilized in methanol and directly injected into the graphite furnace
of an electrothermal atomic absorption spectrometer (ETAAS). An
extraction efficiency of 77% and a sensitivity enhancement factor of 100
were obtained with only 5.00 mL of sample. The limit of detection (LOD)
was 3.3 ng L−1 Tl while the relative standard deviation (RSD) was 5.3% (at 0.4 μg L−1 Tl and n = 10),
calculated from the peak height of absorbance signals. The method was
finally applied to determine Tl species in tap and river water samples
after separation of Tl3+ species. To the best of our
knowledge, this work reports the first application of ILs for Tl
extraction and separation in the analytical field.