Switchable solvent based green liquid phase microextraction method for cobalt in tobacco and food samples prior to flame atomic absorption spectrometric determination

A novel green switchable solvent hyphenated liquid phase microextraction (SS-LPME), preconcentration and extraction methodology has been proposed for the assessment of biologically and nutritionally important element Co(II) from tobacco and food samples by FAAS. A switchable solvent using N,N dimethyl-n-octylamine bicarbonate was synthesized in presence of CO2 to convert from deprotonated to protonated form and each was examined separately for the extraction of Co(II). The quantitative recoveries were achieved. Complex formation between Co(II) and 1-nitroso-2-naphthol under the pH 4.0 was extracted by converting the selected switchable solvent to nonpolar N,N dimethyl-n-octylamine phase. Accuracy and validity was verified through certified reference material (IC-INCT-OBTL-5) and also by addition recovery check. The limit of detection and limit of quantification were 3.2 mu g L-1 and 10.6 mu L-1, respectively. Consequently, the method was effectively carried out for the analysis of cobalt level from tobacco and food samples. (C) 2016 Elsevier B.V. All rights reserved.