The determination of trace organic micro-pollutants by particle beam liquid chromatography mass spectrometry.

Liquid Chromatography/ Mass Spectrometry (LC/MS) is used to interface the separating power of LC with the sensitivity and specificity of MS for the determination of trace levels of organic compounds in a variety of matrices. The technique is finding increasing application in the field of environmental and pharmaceutical analysis. Particle Beam LC/MS (PB/LC/MS) uses a particle beam interface to connect the LC to the MS. This interface design has the advantage of being able to produce "classical" electron impact (El) spectra which can then be searched against commercial MS libraries.The aim of this work was to apply PB/LC/MS to a range of new problems in environmental analysis and evaluate the usefulness of this technique. PB/LC/MS was used to determine compounds that cannot easily be analysed by more conventional techniques such as gas chromatography with mass spectrometry (GC/MS) or liquid chromatography with UV/vis detection (LC/UV). For example, some polycyclic aromatic hydrocarbons (PAH) are too involatile to analyse by GC/MS, some commonly prepared isocyanate derivatives cannot be accurately identified by LC/UV and some classes of pesticides are thermally labile and so cannot be determined by GC/MS.The work presented in this thesis examines the factors affecting the sensitivity and performance of PB/LC/MS and comparisons are made with other analytical methods. Compound classes examined are polycyclic aromatic hydrocarbons (PAH), pesticides and isocyanate derivatives in a variety of environmental matrices. Methods for improving the sensitivity of PB/LC/MS are investigated and the results of these experiments used to compare the different models are used to explain PB/MS behaviour. Conclusions regarding the accuracy of these models are then made. The ability of PB/MS to provide useful El MS for identification purposes in complex environmental matrices is also investigated.