application of thin film microextraction by polymer inclusion membrane for determination of hg2+

Mercury ions (hg2+) are the dominant mercury species in water, and have severe toxic effects on human health and the ecosystem. due to the limitations of traditional analytical methods for mercury determination, such as complex pretreatment and costly instruments, numerous efforts have been made to develop rapid, low-cost, and portable sensors for hg2+ determination [1]. in the past three decades, the development of optical sensors or optodes has progressed. this was primarily because of simplicity, portability and costless devices [2]. in this study, a thin film microextraction based on polymer inclusion membrane (pim) was applied for preconcentration and measurement of mercury(ii) ion. optimized membrane was obtained containing 55% (w/w) polyvinyl chloride base polymer, 40% (2-ethylhexyl) phosphoric acid extractor and 5% diphenylcarbazide chromophore. the variables affecting microextraction efficiency, including ph of solution, ionic strength, stirring rate and extraction time, were also investigated and optimized. the optimize conditions were found at ph 11, 0.02 g/ml of sodium chloride added and extraction time of 30 minutes at room temperature. the analytical performance of the method was evaluated and ‎the proposed method offered linear range between 5 to 100 µg l-1, limits of detection of 1.4 µg l-1 and limit of quantitation of 5 µg l-1, respectively. good precision was demonstrated in terms of the relative standard deviations less than 5.2%. selectivity of the method was evaluated at present of different possible interfering cations and anions. finally, the proposed method was used for determination of mercury in tap water and fish meat samples. relative recovery for tap water sample was determined in the range of 94-110%.