Electrochemical determination of Ga(III) through formation of Ga(III)-deferrioxamine B nanostructures on the glassy carbon electrode surface

Abstract

Selective and sensitive determination of Ga(III) in the presence of Fe(III), as the main interfering ion is studied by using glassy carbon electrode modified with deferrioxamine B (GC-DFO). Characterization and analytical application are performed by different methods including cyclic and differential pulse voltammetry (CV and DPV), electrochemical impedance spectroscopy (EIS), and Field Emission Scanning Electron Microscopy (FESEM). The DPV measurements showed two reduction peaks around -0.630 and -0.830 V. While the current of both peaks varied linearly with Ga(III) concentration of the accumulation solution, the latter was more sensitive and used for construction of the calibration curve. The experimental parameters are studied and optimized. A dynamic calibration curve (6.0×10-11 to 1.4×10-9 mol L-1), including a linear part, from 6.0×10-11 to 1.0×10-9 mol L-1 with mean RSDs of 5.3% for n=3 at 4.0×10-10 mol L-1 Ga(III), and a detection limit of 2.0×10-11 mol L-1 Ga(III) is observed at the optimized conditions. The validity of the method and applicability of the sensor are successfully tested by determining of Ga(III) in natural (river) waters, rice and coal samples. The experimental data are presented and discussed from which the new sensor is characterized. © 2015 Elsevier B.V. All rights reserved.