Ultrasound assisted-hollow fibre liquid-phase microextraction for the determination of selenium in vegetable and fruit samples by using GF-AAS

A rapid, simple and sensitive cleanup procedure is demonstrated for the determination of selenium in vegetable and fruit samples by using ultrasound assisted-hollow fibre-liquid microextraction (UA-HF-LPME) and graphite furnace atomic-absorption spectrometry (GF-AAS). Method is based on the microextraction of selenium from sample solution into 3.5 mu L of organic solvent containing an N-octyl acetamide (OAA) as an extracting agent, which is placed inside the hollow fibre followed by ultrasound irradiation. The parameters that affected the extraction efficiency of selenium from sample solution were investigated. The best optimum conditions for the extraction of selenium were achieved for 15 min of extraction time with 500 rpm of agitation rate at the pH range of 0.8-3.0. The optimised methodology exhibited good linearity between 0.2 and 5 ng mL(-1) selenium with relative standard deviations (RSD) from 2.5% to 4.4%. The proposed method has been successfully applied for the determination of selenium from different types of vegetable and fruit samples. The potentiality of the present (UA-HF-LPME) method was compared with ultrasound assisted-single drop microextraction (UA-SDME). Thus, this approach proves that the UA-HF-LPME technique can be applied as a simple, fast and feasible diagnosis tool for the analysis of selenium in vegetable and fruit samples. (C) 2010 Elsevier Ltd. All rights reserved.