Organic Geochemistry Research Laboratory

Gas Chromatography/Mass Spectrometry (GC/MS)

Gas chromatography/mass spectrometry is an analytical method by which a sample is vaporized and separated into individual organic compounds. These compounds then are simultaneously ionized and fragmented in a vacuum by means of electron bombardment. Each compound has a unique spectrum, providing identification.

GC/MS analyses performed by the Organic Geochemistry Research Laboratory are as follows. The laboratory code is indicated in parentheses after the method description.

• Corn and Soybean Herbicides and Degradation Products (GCS)
• Cotton and Rice Herbicides and Degradation Products (GCR)
• Geosmin, MIB - Taste and Odor (GCG)
• Mosquito insecticides and one synergist (GCM)

Selected GC/MS References

1. Kish, J.L., Thurman, E.M., Scribner, E.A., and Zimmerman, L.R., 2000, Methods of analysis by the U.S. Geological Survey Organic Geochemistry Research Group--Determination of selected herbicides and their degradation products in water using solid-phase extraction and gas chromatography/mass spectrometry: U.S. Geological Survey Open-File Report 00-385, 13 p.

2. Meyer, M.T., Mills, M.S., and Thurman, E.M., 1993, Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis: Journal of Chromatography, v. 629, p. 55-59.

3. Thurman, E.M., Meyer, M.T., Pomes, M., Perry, C.A., and Schwab, A.P., 1990, Enzyme-linked immunosorbent assay compared with gas chromatography/mass spectrometry for the determination of triazine herbicides in water: Analytical Chemistry, v. 62, p. 2043-2048.

4. Zimmerman, L.R., and Thurman, E.M., 1999, Method of analysis by the U.S. Geological Survey Organic Geochemistry Research Group--Determination of triazine and chloroacetanilide herbicides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring: U.S. Geological Survey Open-File Report 98-634, 21 p.

5. Thurman, E.M., Zimmerman, L.R., Aga, D.S., and Gilliom, R.J., 2001, Regional Water-Quality Analysis of 2,4-D and Dicamba in River Water using Gas Chromatography-Isotope Dilution Mass Spectrometry, Intern. J. Environ. Anal. Chem., v. 79(3), p. 185-198.

6. Zimmerman, L.R., Strahan, A.P., and Thurman, E.M., 2001, Method of Analysis and Quality-Assurance Practices by the U.S. Geological Survey Organic Geochemistry Research Group--Determination of Four Selected Mosquito Insecticides and a Synergist in Water Using Liquid-Liquid Extraction and Gas Chromatography/Mass Spectrometry: U.S. Geological Survey Open-File Report 01-273, 11 p.

7. Zimmerman, A.C. Ziegler, and E.M. Thurman, 2002, Method of Analysis and Quality-Assurance Practices by U.S. Geological Survey Organic Geochemistry Research Group--Determination of Geosmin and Methylisoborneol in Water Using Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry : U.S. Geological Survey Open-File Report 02-337, 12 p.