Date of Award
Master of Science in Chemistry
Chris W. Brown
Gas chromatography/infrared spectroscopy (GC/IR) is a powerful analytical technique for "on-the-fly" analysis of multi-component mixtures. The gas chromatograph separates the mixture into single components which are then analyzed by the spectrometer as they elute off the gc column and into the spectrometer. Standard instrumentation usually involves a gas chomatograph, a fourier transform infrared spectrometer (FT-IR), and a computer system. The end products are a reconstructed gas chromatogram and a number of infrared spectra for each of the mixture components. These pieces of information often allow the identification of an unknown mixture. A CC/FT-IR/Computer System, however, is an elaborate and expensive laboratory instrument which requires extensive care, maintenance, and a well trained operator. It is not designed for field use and is seldom deployed outside of a laboratory. The objective of this research therefore was to develop a simple and inexpensive CC/IR/Computer System which would be rugged, easy to use, and readily adaptable for field use.
To do this, we interfaced a fast scanning circular variable filter (CVF) infrared spectrometer to a mini-computer and then coupled the spectrometer/computer to a gas chromatograph. The system was configured such that the same end products generated by a CC/FT-IR/Computer System, i.e. reconstructed gas chromatograms and infrared spectra, are also generated by this GC/CVF-IR/ Computer System. A five component mixture of hazardous class type compounds with closely related boiling points was analyzed to demonstrate the feasibility of this new system.
Ahmadjian, Mark, "Gas Chromatographic/Infared Spectral Analysis Using a Computer Integrated Circular Variable Filter Spectrometer" (1987). Open Access Master's Theses. Paper 943.