Master of Science - Chemistry / Complexation of CrIII was studied using the ligand 2, 2’ Bipyridyl (Bpy). Potentiometric titration was used in the modelling of CrIII-Bpy complexes and establishment of complex stability constants by use of ESTA software package. Investigation of the mechanism involved in the
voltammetric determination of chromium by adsorptive cathodic stripping voltammetry (AdCSV) showed different behavior of chromium in 0.1 M ammonium buffer when compared to a neutral electrolyte (0.1 M sodium nitrate). Alternating current voltammetry (ACV) showed evidence of Bpy adsorption on the electrode surface (HMDE) whereas CrIII did not show any adsorption evidence but complexes of CrIII-Bpy were also adsorbed onto the electrode. Cyclic voltammogram (CV) of Bpy exhibits a reversible process and CrIII was characterized by a quasireversible process.
CrIII-Bpy is investigated here as a model metal-ligand system used in analytical procedure. A set of generalized requirements for the determination of CrIII by AdCSV is proposed and discussed. It is anticipated that the generalized requirements will be applicable to
any metal-ligand system used by that analytical
technique. It is assumed that it should lead to an “educated” choice of a suitable ligand in order to increase selectivity and improve the detection limit in ultra trace analysis (ppb-ppt levels) by AdCSV.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/166 |
| Date | 09 February 2006 |
| Creators | Birame, Christian Sekomo |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 2446284 bytes, application/pdf, application/pdf |
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