Analysis of pharmaceuticals and agrochemicals by LC-MS and SFC-MS using atmospheric pressure ionisation techniques

• Main Author: Williams, L. D.
• Published: Swansea University 2000
• Subjects: 543
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636608

Chapter One involves a brief introduction to the different types of chromatography and mass spectrometry used in this thesis. A further explanation of the ionisation processes used and the interfaces for liquid chromatography and supercritical fluid chromatography coupling to mass spectrometry is provided. The basis of Chapter Two is the separation and analysis of various β-blockers using liquid chromatography-atmospheric pressure ionisation-mass spectrometry. Full analysis was conducted using an ion trap mass spectrometer. The advantages of using involatile phosphate buffers to effect separation was also investigated and novel liquid chromatography-mass spectrometry analysis using these buffers was performed on the patented self cleaning single quadrupole 'aQa' mass spectrometer. Chapter Three involves analysis by liquid chromatography-mass spectrometry of benzodiazepines. The effect of buffer concentration was studied and a comparison made of both atmospheric pressure chemical ionisation and electrospray ionisation, in terms of fragmentation data an detection limits. A comparison of liquid chromatography-mass spectrometry and supercritical fluid chromatography-mass spectrometry for a separation of non-steroidal anti-inflammatory drugs is discussed in Chapter Four. Good resolutions were obtained with both techniques; however, the latter had superior speeds of analysis. Online atmospheric pressure chemical ionisation and electrospray ionisation is discussed and compared. Chapter Five concentrates on packed column supercritical fluid chromatography-mass spectrometry of two differing classes of pesticides. Two analyses were necessary due to the different compound polarities, the first containing a mixture of ten phenylurea and triazine herbicides and the second a mixture of eight acidic herbicides. These analyses provided a useful comparison to the more frequently used liquid chromatography-mass spectrometry.