Develompent of method for voltammetric determination of mercury

In this study, a method has been developed for the direct determination of mercury, one of the most dangerous heavy metals, by anodic square wave voltammetry (SWV). A three-electrode voltammetric system was used for the determination of mercury. In the study, the qualitative determination of mercury was made by cyclic voltammetry, and a peak was observed in both cathodic and anodic directions. Then, the most suitable conditions for the determination of mercury were determined. According to this; pH=7.0 phosphate buffer solution as supporting electrolyte, pencil graphite electrode as working electrode and working range of +0.60 V to -0.60 V vas found. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 1.06×10-7 M and 3.21×10-7 M respectively. When the interference effects of different cations such as Mo3+, Co2+, Fe3+, Cu2+, Pb2+, Cd2+, Ni2+, Ba2+, Bi3+, Sr2+, Mg2+, Ag+ and Cr3+ on the determination of mercury(II) are investigated, only Cu2+, Ag+ and Cd2+ were observed to interfere. When the method was applied to synthetic samples, 4.85 µM of mercury in the sample was determined as 4.32 µM with a relative error of -10.9 % and 0.952 µM of mercury with a relative error of -5.04 % was determined as 0.904 µM. This study demonstrated that determination of mercury can be made directly, quickly, selectively and economically.