Extraction of Cu(II) with dioctyldithiocarbamate and a kinetic study of the extraction using a two-phase microflow system

Abstract

Extraction of Cu(II) with dialkyldithiocarbamates and the extraction kinetics have been studied using a two-phase microflow system. The extraction behavior of Cu(II) with potassium dioctyldithiocarbamate (Kdodtc) was investigated using a batch method to determine the propertes of the synthesized Kdodtc. The extraction ability of dodtc was much greater than that of diethyldithiocarbamate (dedtc) under acid conditions. On the other hand, at higher pH values in the range of 8 - 13, the extraction of Cu(II) with dodtc decreased with increasing pH. This phenomenon was ascribed to the formation of micelles and/or an emulsion, which was caused by the amphiphilic properties of dodtc. The extraction kinetics of Cu(II) was investigated using a glass microchip which was connected to microsyringe pumps and a UV/Vis capillary LC detector. The initial rate constant (kapp) determined for dodtc was greater than that with dedtc. From the relationship between the dodtc concentration and kapp, it was suggested that the extraction rate was governed by the formation of the dodtc complex at the liquid-liquid interface.