Application of a bisindocarbocyanine reagent for dispersive liquid-liquid microextraction of silver with subsequent spectrophotometric determination

The optimum experimental conditions were found to be: pH 6; 0.1 mol L− 1 KI; 5 × 10− 5 mol L− 1 BDIC. The DLLME procedure was carried out using an auxiliary solvent for adjustment of solvent density. A 0.5 mL mixture of toluene as extraction solvent, carbon tetrachloride as auxiliary solvent and ethanol as disperser solvent was used. Ultrasonication of the organic phase was applied to decrease the value of the blank test. The absorbance of the coloured extracts obeys Beer's law in the range 0.07-2.1 mg L− 1 of Ag at 566 nm wavelength. The limit of detection, calculated from a blank test (n = 10) based on 3 s, is 0.03 mg L− 1 of Ag. The developed procedure was applied to the determination of silver in real samples such as Nano Silver and semi-conductor thin films.