Determination of thiobencarb in water samples by gas chromatography using a homogeneous liquid-liquid microextraction via flotation assistance procedure

Abstract

Homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added into the extraction cell which contained an appropriate mixture of toluene (as an extraction solvent) and acetone (as a homogeneous solvent). By using air flotation, the organic solvent was collected at the conical part of the designed cell. The effect of the different parameters on the efficiency of extraction such as type and volume of extraction and homogeneous solvents, ionic strength and extraction time were studied and optimized. Under the optimal conditions, linearity of the method was in the range of 1.0-200 µg L^-1. The relative standard deviations in the real samples varied from 7.8-11.7 % (n = 3). The proposed method was successfully applied to analysis of thiobencarb in the water samples and satisfactory results were obtained.

KEY WORDS: Homogeneous liquid-liquid microextraction, Flotation assistance, Thiobencarb, Gas chromatography, Water samples

Bull. Chem. Soc. Ethiop. 2013, 27(3), 359-366.

DOI: http://dx.doi.org/10.4314/bcse.v27i3.4