Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 147).

Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2005.

Thesis (Ph.D. (Chemistry))--University of Pretoria, 2001. / Summaries in Afrikaans and English.

Thesis (Ph. D.)--University of Hong Kong, 2005.

Thesis (Ph. D.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 489-516).

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17064号 / 工博第3613号 / 新制||工||1548(附属図書館) / 29784 / 京都大学大学院工学研究科航空宇宙工学専攻 / (主査)教授 斧 髙一, 教授 稲室 隆二, 教授 青木 一生 / 学位規則第4条第1項該当

M.Tech. / The Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique showed very high uncertainties associated with the determination of the concentrations of minor elements in the Platinum Group Metal (PGM) smelting plant samples. This project reports on the work done for the identification of, and subsequent minimisation of the sources of uncertainties associated with the measurements of minor elements in the PGM Furnace Matte material by ICP-MS. To perform these studies, Elan 6000, Shimadzu ICPM-8500 and Finnigan Element 2 ICP-M spectrometers were employed. Synthetic Furnace Matte samples (SFMSs) were prepared and used to ascertain the uncertainties associated with the alleged sources at Mintek and Leo-Tech laboratories. The Element 2 spectrometer dominated the other two ICP-M spectrometers in terms of the accuracy for the determination of the concentrations of minor elements in SFMSs. The evidence of spectral interferences from the significant deviations in the measurement results between the isotopes of the same element was observed in the quantification of Zn, Se, Te and Sn in SFMS by the quadrupole Elan 6000 and the Shimadzu spectrometers. It also transpired that the accuracy of the quantitative determination of minor elements in the Furnace Matte (FM) matrix by ICP-MS was hampered by the matrix elements with the severity depending on the specific analyte and the make and model of the ICP-M spectrometer. The Anglo platinum FM material that was analysed in the second round robin was used as a Certified Reference Material (CRM) in the analysis of the Lonmin FM sample. It was revealed that the laboratory standard operating procedures for the preparation, dilution and subsequent analysis of the sample are potential sources of uncertainty in measurement results. The two-fold dilution of the sample for the lessening of the matrix effects was not effective. The use of multi-walled nanotubes for the alleviation of the matrix effects by removal was also not successful. Nevertheless standard addition method (SAM), combined with internal standardisation can be used as an effective calibration method in ICP-MS to achieve less matrix interfered results over the combination of the common external standardisation and internal standardisation methods.

M.Sc. / Emulsions are not widely used in industry for wear-metal-in-oil determinations and this study was undertaken in order to evaluate such a possibility. The use of emulsified standards was compared to aqueous standards for the calibration of an emulsified used lubricating oil sample. The traditionally used methods of ashing in a muffle furnace and dilution with the organic solvent, xylene were also evaluated in comparison with the emulsion methodology. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for the wear-metal-in-oil analysis. The performance characteristics of each method were compared for the following metals: AI, Cr, Cu, Fe, Ni, and Pb. The used oil sample and emulsified standards were acid treated and emulsified in water {1% wlw) using tetralin as solvent and triton X-100 as surfactant. This evaluation included the calibration characteristics, precision and accuracy obtained, as well as the results of recovery studies. The emulsification method was found to be comparable to the ashing and dilution methods in terms of calibration and only Cr, Cu, Fe and Pb concentrations were found. The precision of the emulsification method was found, in general, to be close to or less than 2% RSD. The used oil matrix also contained leaked petroleum from a problem car engine. An accurate determination of lead was consequently impossible since the high lead content led to sedimentation. The use of the internal standard, indium, was evaluated for its effectiveness in correcting possible matrix effects that were evident from the results obtained in the recovery studies. The recovery studies showed the Cr and Pb determinations to be adversely affected by internal standardization. An alternative approach for matrix effect correction, the common analyte internal standardization (CAIS) method was also investigated. This method held promise for allowing the use of aqueous standards, instead of oil or emulsion standards, for the calibration of the emulsified oil samples. Three different applications of the CAIS technique were investigated and all proved unsuccessful.