Utilization of Bis(salicylaldehyde)orthophenylenediamine for the Separation of Gold and Chromium by Capillary Zone Electrophoresis

Abstract

BSOPD, bis(salicylaldehyde) orthophenylenediamine) is investigated as complexing agent in capillary electrophoresis for determination of gold and chromium. BSOPD was chosen as the UV-Visible absorbing chelating ligand because of its ability to form stable complexes with metal ions. Both the metal ions can be determined in single run under optimized conditions with run time of 12 minutes including coexisted ions usually present in waste water. Separation was achieved at optimized conditions of 50 mM phosphate buffer as a background electrolyte at pH =3.4, at applied voltage of -10 kV and detection wavelength of 231 nm. Under above mentioned conditions, limit of quantification (0.5 and 10 μg mL^-1) and detection limit (0.1667 and 3.33 μg mL-1) were found for Au(III) and Cr(VI), respectively. Linear calibration graphs were obtained 0.5 – 50 μg mL^-1 for Au(III) and 10 – 60 μg mL^-1 for Cr(VI) with the correlation coefficient value 0.996 and 0.993, respectively. Utility of this method for metal analysis has been investigated by determining gold from wastewater samples of goldsmith factories and chromium in some environmental waters (portable and polluted).The method was validated by comparing results obtained with capillary zone electrophoresis with atomic absorption spectroscopy.