Voltammetric Determination of Nickel in the Flow System in the Presence of an Extremely Large Excess of Cobalt and Zinc

Abstract

A voltammetric method of nickel determination in the presence of an extremely large excess of cobalt and zinc was proposed. The method is based on a selective deposition of nickel to the metallic state from KSCN solution, then its oxidation to Ni(II) in the presence of dimethylglyoxime with complex formation. The complex is adsorbed onto the electrode and in the stripping step is reduced in an ammonium buffer solution. The measurements were performed in the flow system in the presence of dissolved oxygen. The detection limit for Ni(II) in the presence of 0.01 mol L–1 of Co(II) or in the presence of 0.1 mol L–1 Zn(II) were 1.2×10–9 and 1.3×10–9 mol L– 1, respectively.

2 in 1 versus 1 plus 1 – Outcomes of the transformation of adsorptive stripping method for the Ni2+ and Co2+ determination

“…Various electrode materials, ligands for nickel complexation, and several electrochemical techniques were used for the adsorptive stripping analysis of nickel. Among electrode materials the first and the most frequently used is mercury, in the form of hanging mercury dropping electrode (HMDE) [12][13][14][15][16][17][18][19] and mercury film electrode (MFE) [20][21][22]. Since the year 2000 [23] the majority of the papers published use various types of bismuth electrodes [23][24][25][26], while the usage of various carbon electrodes began a few years earlier [27][28][29][30].…”