Determination of inorganic selenium species in water and garlic samples with on-line ionic liquid dispersive microextraction and electrothermal atomic absorption spectrometry

TALANTA

卷:85

Article

Martinis, Estefania M.¹  Escudero, Leticia B.¹  Berton, Paula¹  Monasterio, Romina P.^1,2  Filippini, Maria F.³  Wuilloud, Rodolfo G.^1,4 

[1] LISAMEN CCT CONICET Mendoza, Analyt Chem Res & Dev Grp QUIANID, Mendoza, Argentina

[2] Univ Nacl La Pampa, Dept Quim, Fac Ciencias Exactas & Nat, Santa Rosa, Argentina

[3] Univ Nacl Cuyo, Dept Ingn Agr, Catedra Quim Agr, Fac Ciencias Agr, RA-5500 Mendoza, Argentina

[4] Univ Nacl Cuyo, ICB, RA-5500 Mendoza, Argentina

关键词: Tetradecyl(trihexyl)phosphonium chloride;    Ionic liquid;    Selenium;    Liquid-liquid microextraction;    Preconcentration;    Speciation;   

DOI  :  10.1016/j.talanta.2011.07.065

来源: Elsevier

【 摘 要 】

A non-chromatographic separation and preconcentration method for Se species determination based on the use of an on-line ionic liquid (IL) dispersive microextraction system coupled to electrothermal atomic absorption spectrometry (ETAAS) is proposed. Retention and separation of the IL phase was achieved with a Florisil (R)-packed microcolumn after dispersive liquid-liquid microextraction (DLLME) with tetradecyl(trihexyl)phosphonium chloride IL (CYPHOS (R) IL 101). Selenite [Se(IV)] species was selectively separated by forming Se-ammonium pyrrolidine dithiocarbamate (Se-APDC) complex followed by extraction with CYPHOS (R) IL 101. The methodology was highly selective towards Se(IV), while selenate [Se(VI)] was reduced and then indirectly determined. Several factors influencing the efficiency of the preconcentration technique, such as APDC concentration, sample volume, extractant phase volume, type of eluent, elution flow rate, etc., have been investigated in detail. The limit of detection (LOD) was 15 ng L-1 and the relative standard deviation (RSD) for 10 replicates at 0.5 mu g L-1 Se concentration was 5.1%, calculated with peak heights. The calibration graph was linear and a correlation coefficient of 0.9993 was achieved. The method was successfully employed for Se speciation studies in garlic extracts and water samples. (C) 2011 Elsevier B.V. All rights reserved.

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