Dispersive Liquid-Liquid Semi-Microextraction of Сu(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 cm3 of 1×10-3 mol/dm3ofDHDPhB, and mixed extractant containing 1 cm3 of chloroform and 1 cm3 of methanol.

Kinetic-Spectrophotometric Determination of Thiocyanate in Human Saliva Based on Landolt Effect in Presence of Astrafloxine FF.

In the present study a kinetic-spectrophotometric method for thiocyanate determination is described. The suggested method for the determination of thiocyanate is based on its "Landolt effect" on the reaction of bromate with hydrobromic acid, which leads to the formation of only one halogen bromine. The reaction was monitored spectrophotometrically at the maximum wavelength of astrafloxine FF light absorption at 535 nm.