Electromembrane extraction-preconcentration followed by microvolume UV-Vis spectrophotometric determination of mercury in water and fish samples.

Electromembrane extraction technique combined with microvolume UV-Vis spectrophotometric detection was proposed for the preconcentration-determination of mercury in water and fish samples. The optimized conditions for preconcentration step were: the applied potential 70V, bis(2-ethylhexyl) phosphate as the extractant in 1-octanol 2% v/v, extraction time 10min, stirring rate 700rpm, acceptor and donor solutions pH 3 and 7, respectively. The linear range was found to be 2.3-950.0μgL and 40-9500μgkg in water and fish samples, with corresponding detection limits of 0.7μgL and 12μgkg, respectively. The method showed satisfactory repeatability and reproducibility (CV<6%). Methodological validation was performed by using cold vapor atomic absorption spectroscopy. The proposed method provided a rapid, sensitive and accurate method which is applicable for routine analysis of total mercury contents in water and fish samples.