| Solid phase microextraction (SPME) has experienced rapid development in the recent decade. Especially for volatile organic compounds in environmental sample analysis, SPME features the special advantages of combining sampling, sample preparation, and sample transfer into a single step. However, due to the complexity of biomatrices and non-volatile and polar nature of the drug compounds, most drug analyses by SPME, and in-tube SPME are still in their primary analytical optimization stage.; Based on the fact that SPME is an equilibrium extraction process, in this thesis, SPME has been successfully applied for drug-protein studies. The theory of protein binding study by headspace SPME was first illustrated with selected alkylbenzene compounds binding to bovine serum albumin (BSA) as the model system. Drug binding to human serum albumin (HSA) was subsequently studied by direct SPME due to the non-volatile and polar nature of the model drug, diazepam. This method can be easily adapted to other drugs. The theoretical as well as the experimental analysis demonstrated that, compared with the traditional methods, SPME is a simple and accurate method for protein binding studies. The small volume SPME method developed in this thesis is useful in the determination of drug binding to expensive proteins since only a very small volume (150 μL for each extraction) of the protein solution is required.; The major difficulty in the analysis of the biological sample with the existing SPME coating materials is the lack of selectivity, which normally results in poor chromatographic separations or/and the poor sensitivity. To overcome the difficulties, immunoaffinity SPME has been developed based on two types of molecular recognition elements: antibodies (Abs) and molecular imprinted polymers (MIPs). Theophylline antibodies were covalently immobilized on the surface of fused silica fiber and on the inner surface of fused silica capillaries for immunoaffinity SPME/in-tube SPME analysis. This method has been successfully applied to human serum analysis.; The research performed in this thesis demonstrates that such materials could have great potential for selective extraction once they can be coated on fused silica surfaces more reliably and effectively. |
