Low-Cost Technique to Monitor Organophosphate Pesticides in Copeland Creek
Project Description: Organophosphorus pesticides are a commonly occurring environmental toxin that is found in agricultural pesticides. These chemicals are similar in composition to Sarin nerve gass and can kill or reproductive damage in fish and amphibians. Pesticide mixes can be more toxic than single pesticides alone.
Solid Phase Microextraction (SPME) is a relatively new technique that is used to separate organic compounds from water so that they can be analyzed by gas chromatography/mass spectroscopy. We refined this technique to target organophosphate detection in samples from Copeland Creek. We are currently working on quantifying the organic pesticides.
Duration: Fall 2013 - Spring 2014
Type of Educational Activities: Independent research
Project Faculty: Mark Perri (Chemistry)
- Center for Environmental Inquiry
- SSU Research, Scholarship and Creative Activity Program (RSCAP)
- Chemistry 494 Independent Research - 3 students
Gas chromatography–mass spectrometry (GC-MS) combines gas-liquid chromatography and mass spectrometry to identify different substances within aquatic samples. Gas chromatography uses a capillary column to separate the molecules and the mass spectrometer then detects ionized molecules based on their different mass-to-charge ratios. Peaks in the resulting spectra are then compared to signatures of known substances to identify the contaminants. Contaminant concentration can be estimated by comparing peak height to solutions with known concentrations of the contaminant.Water samples were collected on July 29, 2013 from 3 sites on Copeland Creek: Commerce Road, Santa Alicia USGS Stream Gauge, and SSU Outfall.
Polar organic compounds were extracted using solid phase microfiber extraction (SPME).
Compounds were desorbed into the injector of a gas chromatograph. As the compounds exit from the chromatograph they enter a mass spectrometer which analyzes the molecular weight of the compound and fragments of the compound that form in the detector. For more details, see Diamond et al. 2104, and Diamond 2014 below in "Resulting Data & Reports."
Field collection and laboratory techniques were undertaken by SSU students under the guidance of Dr. Mark Perri.
Data (see data disclaimer)
- Chromatography and Mass Spectometry (xlsx) 2012-present: pesticides
- Measurements of Organic Pollutants on the SSU Campus. Ben Diamond, Michael Haggmark, and Erin Ballantyne (Advisor: Mark Perri, Chemistry 494 Independent Research). Diamond et al. 2014 (poster pdf; 1.8 Mb); 2014 WATERS abstracts
- Method Development for the Monitoring of Organophosphate Pesticides in Copeland Creek and Local water ways via Solid Phase Micro Extraction coupled with Gas Chromatography Mass Spectrometry. Diamond 2014 Senior Seminar (ppt pdf, 2 Mb).
- Atkinson, R. and J. Arey (1998). "Atmospheric Chemistry of Biogenic Organic Compounds." Accounts of Chemical Research 31(9): 574-583.
- Brilli, F., et al. (2012). "Qualitative and Quantitative Characterization of Volatile Organic Compound Emissions from Cut Grass." Environmental Science & Technology 46(7): 3859-3865.
- Custer, T. and G. Schade (2007). "Methanol and acetaldehyde fluxes over ryegrass." Tellus B 59(4): 673-684.
- Van Opstaele, F., et al. (2012). "Characterization of Novel Varietal Floral Hop Aromas by Headspace Solid Phase Microextraction and Gas Chromatography–Mass Spectrometry/Olfactometry." Journal of Agricultural and Food Chemistry 60(50): 12270-12281.
- Scholz, N. L., et al. (2012). "A Perspective on Modern Pesticides, Pelagic Fish Declines, and Unknown Ecological Resilience in Highly Managed Ecosystems." Bioscience 62(4): 428-434.
- Laetz, C. A., et al. (2013). "Interactive Neurobehavioral Toxicity of Diazinon, Malathion, and Ethoprop to Juvenile Coho Salmon." Environmental Science & Technology 47(6): 2925-2931.