Commercial development and applications of proton transfer reaction-mass spectrometry

Dassonville, Renaud Roger Antoine (2022). Commercial development and applications of proton transfer reaction-mass spectrometry. University of Birmingham. Ph.D.

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Abstract

Proton Transfer Reaction-Mass Spectrometry (PTR-MS) has been in use since the 1990s for real-time measurement of trace volatile organic compounds (VOCs) from parts per million by volume down to sub-parts per billion by volume in a wide range of applications such as environmental monitoring, health, homeland security and food sciences.
The work presented in this thesis deals with new developments and applications of PTR-MS and has different interconnected themes. The first is hardware development; principally the testing and characterisation of new radio frequency (RF) ion-funnels within the PTR reactor designed to improve ion transmission and thus sensitivity of detection for trace compounds. The desire to characterise better the effect of RF fields on analyte ions in the reactor led to a fundamental study in which the proportion of analyte product ions was determined as a function of the reduced electric field strength, first without the application of RF fields. This was to compare their behaviours when subject to RF fields. An unexpected and previously unreported shift in these product ion distributions was discovered, depending upon how the reduced electric field, E/n, was created.
A second theme is the creation of a methodology for, and production of, a mass spectral library for individual VOCs analysed by PTR-MS. This was to assist in the development and testing of a new software algorithm for compound identification and quantification of complex VOC mixtures when no pre-separation technique such as gas chromatography (GC) is used.
The third theme is the application of both these hardware and software developments in the practical analysis of VOCs, not just in ambient air but also in water, where a portable water sampler has also been developed, so that impurities in water could be determined with high specificity and sensitivity in real-time. This has been used in tandem not only with PTR-MS, but also with two more conventional portable electron impact mass spectrometers (EI-MS). One of these analysers was taken to Mainz, Germany, as part of a secondment, to investigate the possibility of using the instrument instead of the more expensive and complicated PTR-MS for determination of a parameter of interest to atmospheric chemists: ‘the total OH reactivity' of the atmosphere.
The work in this thesis was conducted as part of a Marie Skłodowska-Curie Actions Innovative Training Network (ITN): Ion-Molecule Processes for Analytical Chemical Technologies (IMPACT). This European ITN programme was named through the European Commission’s HORIZON 2020 Programme. The work was directly influenced by the desire to improve analytical tools available to a commercial analytical instrument manufacturer, Kore Technology Ltd, at whose premises most of the work took place.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):