Silica gel with covalently immobilized thiosemicarbazide for dynamic preconcentration of copper(II) and zinc(II)

Abstract

А new thiosemicarbazide modified silica gel sorbent was prepared and applied for preconcentration of Cu(II) and Zn(II) prior to the measurement by X-ray fluorescence spectroscopy. The optimization of some analytical parameters affecting the adsorption of the analyte such as sample flow rate and volume, eluent condition, and interfering substances were investigated. The sorbent was used to remove Сu(II) and Zn(II) in a dynamic mode. Changing the speed of pumping solution from (0.5 ml / min to 4.5 ml / min ) as an increase in volume from 50 ml to 2000 ml with levels of concentrations did not affect the recovery of Cu(II) and Zn(II). The conditions for the dynamic concentration, and X-ray fluorescence determination of Cu(II) and Zn(II) on the resultant complexing silica from aqueous samples with a total salinity of 35 g / l , containing equimolar amounts of Ni(II), Co(II), Cd(II). Established preservation sorption capacity of silica gel with respect to Cu(II), Zn(II) after 10 cycles of sorption – desorption.