Analytical Equipment
Inorganic Geochemistry Page 3
Some of our equipment is considered part of a regional pool. Investigators with legitimate research needs are invited to contact the Geology Department to learn what arrangements are necessary to use our facilities in their work. Cover "Department" in the navigation bar at the top of the page with your cursor, and then select "E-Mail Us" to compose and send an e-mail.
Thermo-Finnigan MAT 253 Mass Spectrometer
This is our Thermo-Finnigan MAT 253 isotope ratio mass spectrometer, being shown
to us here by Ph.D. student Mathieu Richaud. It is equipped with a "gas bench"
for isotopic analyses of water and
carbonates, the latter following acid dissolution, and a Thermally-Coupled Elemental
Analyzer ( TC-EA, it's essentially a furnace ) for use with solid or organic samples
to study O, N, C, and S isotopes. Drs.
Gene Perry,
Paul Loubere,
Melissa Lenczewski,
and their students use this instrument in their research.
Dr. Perry is involved in a very interesting project currently on the MAT 253 which has to do with the fact that the isotopic signature of hurricane precipitation is different from that of ordinary rain. It is therefore possible to trace hurricane events as their precipitation enters and moves through groundwater systems, and to use this signature to map those systems. Dr. Loubere and his students use the MAT 253 and its automated acid reaction system to analyze the stable isotopes of marine calcite microfossils. This is to discover how the marine carbon cycle has responded to climate change in the recent geological past; and to clarify the role of the ocean system in regulating climate change associated with variations in atmospheric carbon dioxide content. Finally, Dr. Lenczewski is using the TC-EA apparatus to examine the isotopic composition of elements along a core taken from a tree. With this approach, it is possible to examine isotopic variations as a function of time -- by tree ring count -- and document environmental changes that may have occurred during the lifetime of the tree.
Thermo-Finnigan LCQ Advantage MAX
We have a laboratory, only just completed, that is dedicated to the study of organic materials in the environment. It is operated by Dr. Melissa Lenczewski, and this instrument is part of that lab. It is an HPLC, or High-Pressure Liquid Chromatograph, that can separate organic molecules according to the time required to release them from an ion-exchange resin. Comparison to the release times of compounds contained in a standard solution allows identification of those present in the sample.
Master's degree student Kristine Karuhn is using the instrument to look for pharmaceutical chemicals, such as caffeine and ibuprofen, in groundwater as her master's project. She's testing the idea that such chemicals will be more likely to be found in nitrate and phosphate pollution from domestic sources, such as septic tanks, than in that from agricultural or other industrial sources.
Thermo-Finnigan DELTAplus Advantage Mass Spectrometer
The other instrument in Dr. Melissa Lenczewski's, new organic geochemistry laboratory is this dual-source Thermo-Finnigan DELTAplus Advantage mass spectrometer. Whereas our Varian GC-MS is used to identify the organic compounds present, this instrument is used to determine the isotopic signatures of those organic compounds. For example, samples containing the chemical benzene, as identified using the Varian instrument, may have different isotopic signatures depending upon the source or manufacturer of the benzene.
Master's degree student Kristine Kahrun is showing us the gas chromatograph source for the DELTAplus Advantage, which is used to analyze relatively volatile organic species. Behind her and to the left, partially obscured by the chimney of the GC source, is the tall cabinet that houses the high-pressure liquid chromatograph source used for less-volatile species. The mass spectrometer itself is in the low cabinet immediately behind Kristine.
This instrument is so new that there have not yet been assigned any analytical projects to it.
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This page was made by Neil Dickey. If you have questions or comments, feel free to e-mail me.
Last updated 08/28/06