Dispersive Liquid-Liquid Semi-Microextraction Of Cu(Ii) With 6,7-Dihydroxy-2,4-Diphenylbenzopyrylium Chloride For Its Spectrophotometric Determination

A novel dispersive liquid-liquid semi-microextraction (DLLsME) procedure for copper(II) preconcentration is proposed. The system containing copper(II) and 6,7-dihydroxy-2,4-diphenylbenzopyrylium chloride (DHDPhB), after addition a mixture of chloroform and methanol becomes cloudy and the formation of the organic phase was observed immediately. The optimal conditions of DLLsME were found to be: pH 5, absorption band maximum was 570 nm, 1 cm(3) of 1 x 10(-3) mol/dm(3) of DHDPhB, and mixed extractant containing 1 cm(3) of chloroform and 1 cm(3) of methanol. Under optimal conditions, the calibration plot was linear in the range of copper(II) concentration 4.32-65 mu g/dm(3) and the limit of detection was 1.29 mu g/dm(3). The rocks and tap water samples were successfully analyzed according to the suggested procedure with RSD no more than 4.9%.