PhD Civil Engineering: Environmetal Engineering and Forensics
Course Director: n/a
Year of Study: 1st Year
Development of the control system for an advance on-line position-specific stable carbon isotope system for Environmental Investigation
Dr. Caroline Gauchotte
The aim of this project is to develop an automatically controlled interface for the PSIA system for the use in environmental forensic investigations.
To achieve the aims of this project, the following research objectives are identified:
- To develop and designs control system for PSIA
- To build an automated interface for PSIA
- Test the fit-forpurposeness of the system for environmental applications.
GCxGC, isotope, PAHs, postion specific
Compound-specific stable isotope (CSIA) is a an analytical tool for measuring intermolecular isotopic variations and in the last fifteen years, it has taken a major role in Environmental Forensic for the determination of contamination sources but also for the monitoring of biodegradation progress. At the University of Strathclyde, the advanced on-line position-specific carbon isotope system (PSIA) has been developed as powerful complementary method. The advance PSIA is an analytical device that measures intramolecular isotropic variations. After injection of the sample into the system, the various compounds in the sample pass first through an initial gas chromatography column and then the compound of interest is isolated and directed into an interface, which comprises a pyrolysis furnace and a cryo-focusing module, before going into secondary gas chromatography. Thereafter the sample will pass into Time-of-Flight Mass Spectrometer (TOFMS) for molecular identification of the pyrolysis products or an Isotope Ratio Mass Spectrometry (IRMS) to determine the isotope ratios of these products. The flow rate in the system is one of the key factors to the accuracy and sensibility of the results because first, it determines the time spent by the compound of interest in the furnace and thus the pyrolysis reaction time and secondly because it affects the width of the peaks in the second column. In the system, the flow rates are controlled by pressure of helium gas and temperature. For optimal functioning of the system, it is crucial that the flow rate in the interfacing module and the second column can be controlled. The PSIA system is still a prototype and most of the controlling functions are manually operated. To avoid operator related run-to-run variations and optimized operation, the pyrolysis-cryofocusing module needs to be developed into an automatically operating system. As a first stage for automation of the system, Lab VIEW will be used as the control system of the interface design software combine with electrical-to-mechanical control system. Then an all automated interface for PSIA will be build and the system fit-for-purposeness will be tested by developing environmental application of on-line PSIA.