On-line ionic liquid-based preconcentration system coupled to flame atomic absorption spectrometry for trace cadmium determination in plastic food packaging materials

TALANTA

卷:78

Article

Martinis, Estefania M.^1,2,3  Olsina, Roberto A.^3,5  Altamirano, Jorgelina C.^1,2,3,4  Wuilloud, Rodolfo G.^1,2,3,4 

[1] CCT CONICET Mendoza, Environm Res Lab, Mendoza, Argentina

[2] CCT CONICET Mendoza, Serv Mendoza LISAMEN, Mendoza, Argentina

[3] Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF, Argentina

[4] Univ Nacl Cuyo, Inst Ciencias Basicas, RA-5500 Mendoza, Argentina

[5] Univ Nacl San Luis, INQUISAL CONICET, Dept Quim Analit, Fac Quim Bioquim & Farm, San Luis, Argentina

关键词: 1-Butyl-3-methylimidazolium;    hexafluorophosphate;    Room temperature ionic liquid;    Cadmium;    On-line preconcentration;    Plastic food packaging material;   

DOI  :  10.1016/j.talanta.2008.12.051

来源: Elsevier

【 摘 要 】

A novel on-line preconcentration method based on liquid-liquid (L-L) extraction with room temperature ionic liquids (RTILs) coupled to flame atomic absorption spectrometry (FAAS) was developed for cadmium determination in plastic food packaging materials. The methodology is based on the complexation of Cd with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) reagent after sample digestion followed by extraction of the complex with the RTIL 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF6]). The mixture was loaded into a flow injection analysis (FIA) manifold and the RTIL rich-phase was retained in a microcolumn filled with silica gel. The RTIL rich-phase was then eluted directly into FAAS. A enhancement factor of 35 was achieved with 20 mL of sample. The limit of detection (LOD), obtained as IUPAC recommendation, was 6 ng g(-1) and the relative standard deviation (R.S.D.) for 10 replicates at 10 mu g L-1 Cd concentration level was 3.9%, calculated at the peak heights. The calibration graph was linear and a correlation coefficient of 0.9998 was achieved. The accuracy of the method was evaluated by both a recovery study and comparison of results with direct determination by electrothermal atomic absorption spectrometry (ETAAS). The method was successfully applied for Cd determination in plastic food packaging materials and Cd concentrations found were in the range of 0.04-10.4 mu gg(-1). (C) 2009 Elsevier B.V. All rights reserved.

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