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

• Published in: Microchemical journal Vol. 99; no. 2; pp. 514 - 522
• Main Authors: Kocúrová, Lívia, Balogh, Ioseph S., Nagy, Lajos, Billes, Ferenc, Simon, András, Andruch, Vasil
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2011
• Subjects: Auxiliary solvent; Bisindocarbocyanine reagent; Dispersive liquid–liquid microextraction; Silver; Ultrasound; Silver; Auxiliary solvent; Bisindocarbocyanine reagent; Ultrasound; Dispersive liquid–liquid microextraction
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2011.07.002

A novel, simple and environmentally friendly procedure for silver determination has been developed. The method is based on ion associate formation of AgI2− and bisindocarbocyanine chloride (BDIC) reagent, followed by dispersive liquid–liquid microextraction (DLLME) of the ion associate formed and subsequent UV–Vis spectrophotometric detection. The structure of BDIC and the reaction mechanism were investigated by MS and NMR measurements and quantum chemical calculations.
The optimum experimental conditions were found to be: pH 6; 0.1molL−1 KI; 5×10−5molL−1 BDIC. The DLLME procedure was carried out using an auxiliary solvent for adjustment of solvent density. A 0.5mL 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 0.07–2.1mgL−1 of Ag at 566nm wavelength. The limit of detection, calculated from a blank test (n=10) based on 3s, is 0.03mgL−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.