In modern chemical laboratories, high performance liquid chromatography (HPLC) has become the technique of choice amongst separation scientists as evidenced by the huge body of published literature that employ the technique as the pre-eminent analytical method. Increasingly analytical chemists are seeking to determine the chemical signature (or fingerprint) of complex and perhaps even simple samples. The analysis of environmental samples, natural products, such as essential oils, the evaluation of illicit drugs, or the quality assurance of pharmaceuticals are just four areas where chemical fingerprinting may be important. The chemical classification of these types of mixtures can be undertaken using chromatographic methods of analysis coupled with detection processes that provide identification ie. mass spectroscopy (MS), infrared spectroscopy (IR), atomic spectroscopy (ICP) and nuclear magnetic resonance spectroscopy (NMR). While these techniques find widespread use and their applications are growing at a rapid rate, their limitations as routine applications for determining chemical signatures, is limited by the initial purchase price and the high associated running costs; especially for hyphenated liquid chromatographic systems. In general, a high degree of operator expertise is also required to ensure correct operation and interpretation of the results. While complete chemical specification may be undertaken by using multiple hyphenated methods, none of the above mentioned techniques provide for a rapid means of detection on a routine or continuous mode of operation. This can limit their application. However, an alternative to monitor and evaluate the chemical signature of complex samples is to employ multidimensional separations. In the expanded multidimensional separation space the probability that two species will elute with exactly the same retention time in both separation dimensions decreases compared to the one-dimensional separation. This probability further decreases as the separation mechanisms become more divergent and the two-dimensional separation space is maximised. Hence, the uniqueness of a two-dimensional retention time increases and thereby the multidimensional separation approach becomes a means of chemical fingerprinting. Hence 2D-HPLC technique is a powerful and less expensive method of separation compared to hyphenated techniques. This thesis describes the development of a stand-alone 2D-HPLC system for the separation of complex samples. A comprehensive 2D-HPLC software package has been developed for data acquisition, hardware control, data processing and graphical presentation. Two data acquisition hardware modules have also been developed. These hardware and software modules have been integrated with existing equipment in our laboratory. The performance of this newly developed 2D-HPLC system has been successfully evaluated. All these details have been described in the five chapters of this thesis. / Master of Science (Honours)
| Identifer | oai:union.ndltd.org:ADTP/189475 |
| Date | January 2004 |
| Creators | Toups, Erich P., University of Western Sydney, College of Science, Technology and Environment, School of Science, Food and Horticulture |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
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