The Solid-Phase Extraction of Drugs From Biological Fluids

Moore, Christine Mary (1989) The Solid-Phase Extraction of Drugs From Biological Fluids. PhD thesis, University of Glasgow.

Abstract

Solid-phase extraction has become an increasingly important technique over the last decade. In this study, the properties of bonded silica sorbents for use in the solid-phase extraction of drugs from various biological fluids are investigated. Sorbents exhibiting predominantly non-polar, polar or ion-exchange interactions are all considered. Initially, the extraction of some common benzodiazepines (diazepam, triazolam, flunitrazepam and their metabolites), from the urine of racing greyhounds is studied. Further method development is described involving the extraction of xylazine (a veterinary tranquilliser), from greyhound urine, mazindol (a central nervous system stimulant), from racehorse urine, and basic drugs from human post-mortem urine samples. Comparison of these solid-phase methods with existing solvent extraction procedures, from an efficiency point of view, is carried out for racing greyhound and human post-mortem samples. Such comparisons are based on a number of criteria: the total time spent on extraction; solvent cost; glassware requirements; sample requirements; possible simultaneous extraction of a number of samples; potential automation of extraction; cleanliness of extracts, and necessity for evaporation and/or derivatisation steps prior to analysis. The extraction methods presented are all reproducible and highly efficient as well as being economically viable for routine use in a toxicological laboratory. Further applications of solid-phase extractions are investigated. A novel high-pressure liquid chromatographic (HPLC) analysis method for benzodiazepines is described, which is compatible with liquid chromatography-mass spectrometry (LC-MS). New HPLC methods for xylazine and mazindol analysis are developed. Finally, a potentially fully automated basic drug screening solid-phase extraction method and analysis by HPLC with diode array detection for the determination of drugs from human post-mortem urine samples is described. The results of this method were confirmed by gas chromatography-mass spectrometry (GC-MS).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Analytical chemistry
• Date of Award: 1989
• Depositing User: Enlighten Team
• Unique ID: glathesis:1989-77915
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:48
• Last Modified: 30 Jan 2020 15:48
• URI: https://theses.gla.ac.uk/id/eprint/77915