Timothy W. Collette
Biographical Information
Name: Timothy W. Collette
Title: Research Chemist
Education:
B.S. 1981 Chemistry Berry College Rome, Ga.
Ph.D. 1985 Physical Chemistry University of Georgia, Athens, Ga.
Research Interests:
Tim's research has been directed primarily at the development and application of vibrational spectroscopic tools for solving difficult environmental problems. This has involved four main areas. First, is the identification of unsuspected pollutants in environmental samples using infrared and Raman spectroscopy, often in concert with mass spectrometry. Of particular concern has been identifying the organic byproducts formed when drinking water is treated with disinfectants other than chlorine. Second, is the development of an infrared spectroscopy-based method for the prediction of parameters used for environmental fate assessments (e.g., physical/chemical property constants, equilibrium constants, reaction rate constants). This method, when fully developed, will allow rapid estimation of parameters that currently take weeks to measure. Third, Tim has been interested in the application of Raman spectroscopy for the speciation of complex (hydrophilic, polyfunctional, ionizable) organics in water. Methods for identifying and quantifying chemical species, such as tautomers, hydrated complexes, ions and zwitterions, are currently under development. Accurate speciation of complex organics is essential for sound risk and exposure assessment. Most recently, Tim has been studying the effects that drinking water treatment have on the pesticides and toxic chemicals that occur in drinking water sources. Sometimes these compounds are removed or detoxified by drinking water treatment, but sometimes they are made more toxic. Understanding and modeling this complex behavior is a challenge that must be met to improve chemical risk assessments.
Selected Recent Publications:
"A Method for the Measurement of Site-specific Tautomeric and Zwitterionic Microspecies Equilibrium Constants" J.C. D'Angelo and T.W. Collette, Anal. Chem. 69, 1642-1650 (1997).
"Identification of Drinking Water Contaminants in the Course of a Childhood Cancer Investigation in Toms River, NJ" S.D. Richardson, T.W. Collette, P.C. Price, F. A. Genicola, J.W. Jenks, A.D. Thruston, Jr., and J.J. Ellington., J. Expos. Anal. Environ. Epidem. 9, 200-216 (1999).
"Identification of New Drinking Water Disinfection Byproducts Formed in the Presence of Bromide," S.D. Richardson, A.D. Thruston, Jr., T.V. Caughran, P.H. Chen, T.W. Collette, T.L. Floyd, K.M. Schenck, B.W. Lykins, Jr., G. Sun, and G. Majetich, Environ. Sci. Technol. 33, 3378-3383 (1999).
"Optimization of Raman Spectroscopy for Speciation of Organics in Water," T.W. Collette T.L. Williams, and J.C. D'Angelo, Appl. Spectros. 55, 750-766 (2001).
"Raman Spectroscopic Analysis of Fertilizers and Plant Tissue for Perchlorate," T.L Williams, R.B. Martin, and T.W. Collette, Appl. Spectros. 55, 967-983 (2001).
"Prediction of Molecular Properties with Mid-Infrared Spectra and Interferograms" T. W. Collette, Appl. Spectros. 55, 1067-1078 (2001).
"The Role of Raman Spectroscopy in the Analytical Chemistry of Potable Water" T.W. Collette and T.L. Williams, J. Environ. Monitor. 4, 27-34 (2002).
"Analysis of Hydroponic Fertilizer Matrixes for Perchlorate: Comparison of Analytical Techniques" T.W. Collette, T.L Williams, E.T. Urbansky, M.L. Magnuson, G.N. Hebert, and S.H. Strauss, Analyst, 128, 88-97 (2003).
Current Projects:
Importance of Proper Flatfielding for Raman Analysis of Low-Level Organics in Water
Extension of Temperature-Variant Raman Method for Speciation of Organics in Water via High Pressure Analysis
Utility of Ionic Strength Variation for Speciation of Organics in Water
Fate of Pesticides and Toxic Chemicals During Drinking Water Treatment
Raman Spectroscopy-Based Metabonomics with Teflon AF Waveguides