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The McNeill Research Group studies chemical reactions in aquatic systems, focusing on detailed mechanisms of fate processes of organic molecules.  The group develops and applies new methods in an effort to bring a deeper chemical understanding of aquatic systems.  There is an additional emphasis on maintaining a broad range of expertise and project types in the  group.  Presently, there are projects in analytical chemistry (e.g., analysis of novel dioxins in sediments), laser spectroscopy (e.g., photochemical mechanisms), synthetic organic chemistry (e.g., preparation of molecular probes for reactive oxygen species), mechanistic inorganic chemistry (e.g., defluorination catalysis), and field studies.

Check out our group publications on Google Scholar.

You can also follow Kris McNeill on Twitter.

Emerging contaminant photochemistry


Emerging classes of environmental contaminants, which often differ significantly from traditional legacy pollutant classes in their molecular properties, provide many significant research challenges.  Pharmaceutical compounds in surface waters are a good example of this category of contaminants and represent a major research effort in our group.  In collaboration with Prof. William Arnold (Univ. of Minnesota, Dept. of Civil and Environmental Engineering), we are developing mechanism-based models that will help predict the photochemical lifetimes of pharmaceuticals in natural systems. In addition to pharmaceuticals, we have ongoing projects on the degradation mechanisms of brominated flame retardant chemicals, and new classes of pesticides.


Representative Recent Publications

R. U. Halden, A. E. Lindeman, A. E. Aiello, D. Andrews, W. A. Arnold, P. Fair, R. E. Fuoco, L. A. Geer, P. I. Johnson, R. Lohmann, K. McNeill, V. P. Sacks, T. Schettler, R. Weber, R. R. Zoeller, A. Blum, The Florence Statement on Triclosan and Triclocarban, Environ. Health Persp. 2017, 125, DOI:10.1289/EHP1788.


C. Davis, P. R. Erickson, K. McNeill, E. M.-L. Janssen, Environmental Photochemistry of Fenamate NSAIDs Environ. Sci. Processes Impacts 2017, 19, 656-665


K. H. Wammer, K. C. Anderson, P. R. Erickson, S. Kliegman, M. E. Moffatt, S. M. Berg, J. A. Heitzman, N. C. Pflug, K. McNeill, D. Martinovic-Weigelt, R. Abagyan, D. M. Cwiertny, E. P. Kolodziej, Environmental Photochemistry of Altrenogest: Photoisomerization to a Bioactive Product with Increased Environmental Persistence via Reversible Photohydration, Environ. Sci. Technol. 2016, 40, 7480-7488.

J. F. Kerrigan, D. R. Engstrom, D. Yee, C. Sueper, P.R. Erickson, M. Grandbois, K. McNeill, W. A. Arnold, Quantification of Hydroxylated Polybrominated Dipenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems, PloS one, 2015 e0138805. 

E. M. L. Janssen, E. Marron, K. McNeill, Aquatic photochemical kinetics of benzotriazole and structurally related compounds, Environ. Sci. Processes Impacts 2015, 17, 939-946.

S. Kliegman, S. N. Eustis, W. A. Arnold, K. McNeill, Experimental and theoretical insights into the involvement of radicals in triclosan phototransformation, Environ. Sci. Technol., 2013, 47, 6756-6763.


F. Bonvin, J. Omlin, R. Rutler, W. B. Schweizer, P. J. Alaimo, T. Strathmann, K. McNeill, T. Kohn, Direct photolysis of human metabolites of the antibiotic sulfamethoxazole: Evidence for abiotic back-transformation, Environ. Sci. Technol., 2013, 47, 6746-6755.


K. H. Wammer, A. R. Korte, R. A. Lundeen, J. E. Sundberg, K. McNeill, and W. A. Arnold, Direct photochemistry of three fluoroquinolone antibacterials: Norfloxacin, ofloxacin, and enrofloxacin, Water Res., 2013, 47, 439-448.


C. Anger, C. Sueper, D. Blumentritt, K. McNeill, D. Engstrom, W. A. Arnold, Quantification of Triclosan, Chlorinated Triclosan Derivatives, and their Dioxin Photoproducts in Lacustrine Sediment Cores, Environ. Sci. Technol., 2013, 47, 1833-1843.


P. R. Tentscher, S. N. Eustis, K. McNeill, J. S. Arey, Aqueous oxidation of sulfonamide antibiotics: aromatic nucleophilic substitution of an aniline radical cation, Chem. Eur. J., 2013, 19, 11216-11223.


P. R. Erickson, M. Grandbois, W. A. Arnold, K. McNeill, Photochemical formation of brominated dioxins and other products of concern from hydroxylated polybrominated diphenyl ethers (OH-PBDEs), Environ. Sci. Technol., 2012, 46, 8174–8180.

Chemical products of the future


Part of our research group concerns itself with chemical products that are thought to increase in significance in the coming decades.  Two classes of chemicals that we are currently studying are fluorocarbons and biodegradable polymers, in collaboration with Dr. Michael Sander, who leads the polymer project. In both of these cases, there is expected to be major growth in the production and use of these compound classes, and there is limited knowledge about their environmental behavior.  Whether fluorocarbons follow the same trajectory as chlorocarbons and become widespread persistent organic pollutants remains an open question.  Nevertheless, we are seeking remediation solutions for these compounds in anticipation of contaminated sites in the future.  In the case of biodegradable polymers, these are materials that have been specifically designed to limit their environmental impact and are therefore have potential to replace conventional polymers in various applications.  Even so, it is important to study the environmental fate of these materials before their use increases.


Representative Recent Publications

M. T. Zumstein, A. Schintlmeister, T. F. Nelson, R. Baumgartner, D. Woebken, M. Wagner, H.-P. E. Kohler, K. McNeill, M. Sander, Biodegradation of synthetic polymers in soils: tracking carbon into CO2 and microbial biomass, Science Advances 2018, 4, aas9024. 


G. X. De Hoe, M. T. Zumstein, B. J. Tiegs, J. P. Brutman, K. McNeill, M. Sander, G. W. Coates, M. A. Hillmyer, Sustainable Polyester Elastomers from Lactones: Synthesis, Properties, and Enzymatic Hydrolyzability. J. Am. Chem. Soc. 2018, 140, 963 - 973.


L. Schinkel, S. Lehner, M. Knobloch, P. Lienemann, C. Bogdal, K. McNeill, N. V. Heeb, Transformation of chlorinated paraffins to olefins during metal work and thermal exposure – Deconvolution of mass spectra and kinetics, Chemosphere, 2018, 194, 803–811.


M. T. Zumstein, D. Rechsteiner, N. Roduner, V. Perz, D. Ribitsch, G. M. Guebitz, H.-P. Kohler, K. McNeill, M. Sander, Enzymatic hydrolysis of polyester thin films at the nanoscale: effects of polyester structure and enzyme active-site accessibility, Environ. Sci. Technol. 2017, 51, 7476–7485.


L. Schinkel, S. Lehner, N. Heeb, P. Lienemann, K. McNeill, C. Bogdal, Deconvolution of mass spectral interferences of chlorinated alkanes and their thermal degradation products: chlorinated alkenes, Analytical Chemistry 2017, 89, 5923-5931.

M. T. Zumstein, H.-P. E. Kohler, K. McNeill, M. Sander, High-throughput analysis of enzymatic polyester hydrolysis by monitoring co-hydrolysis of a polyester-embedded fluorogenic probe, Environ. Sci. Technol. 2017, 51, 4358–4367.


M. T. Zumstein, H. P. E. Kohler, K. McNeill, M. Sander, Enzymatic Hydrolysis of Polyester Thin Films: Real-Time Analysis of Film Mass Changes and Dissipation Dynamics, Environ. Sci. Technol. 2015, 50, 197-206.


D. Sadowsky, K. McNeill, C. J. Cramer, Dehalogenation of Aromatics by Nucleophilic Aromatic Substitution, Environ. Sci. Technol. 2014, 48, 10904–10911.


D. Sadowsky, K. McNeill,  C. J. Cramer, Thermochemical Factors Affecting the Dehalogenation of Aromatics, Environ. Sci. Technol. 2013, 47, 14194–14203.


E. J. Pelton, D. A. Blank, K. McNeill, Dechlorination of chlorinated ethylenes by a photochemically generated iron(0) complex, Dalton Trans., 2013, 42, 10121-10128.


R. Baumgartner, G. Stieger, K. McNeill, Complete Hydrodehalogenation of Polyfluorinated and other Polyhalogenated Benzenes under Mild Catalytic Conditions, Environ. Sci. Technol., 2013, 47, 6545-6553.


R. Baumgartner, K. McNeill, Hydrodefluorination and hydrogenation of fluorobenzene under mild aqueous conditions Environ. Sci. Technol., 2012, 46, 10199–10205.


E. E. Marlier, B.A. Ulrich, K. McNeill, Synthesis and Reactivity of an Isolable Cobalt(I) Complex Containing a β-Diketiminate-Based Acyclic Tetradentate Ligand, Inorg. Chem., 2012, 51, 2079–2085.

Natural organic matter and reactive oxygen species


A major area of interest in our group is the production and consumption of reactive oxygen species (ROS) from the photochemical and non-photochemical reactions of natural organic matter. Projects in this area include developing detection methods for ROS, studying the spatial distribution of these species in natural waters, and understanding how they interact with their precursor material, natural organic matter. The goal is to develop a detailed understanding of the production, distribution, and behavior of ROS for an improved understanding of their role in the transformations of both pollutants and natural compounds. 


Representative Recent Publications

G. McKay, J. A. Korak, P. R. Erickson, D. E. Latch, K. McNeill, F. L. Rosario-Ortiz, The case against charge transfer interactions in dissolved organic matter photophysics, Environ. Sci. Technol. 2018, 52, 406-414.


M. Schmitt, P. R. Erickson, K. McNeill, Triplet state dissolved organic matter quantum yields and lifetimes from direct observation of aromatic amine oxidation, Environ. Sci. Technol. 2017, 51, 13151-13160.


V. S. Lin, M. Grandbois, K. McNeill, Fluorescent molecular probes for detection of one-electron oxidants photochemically generated by dissolved organic matter, Environ. Sci. Technol. 2017, 51, 9033 - 9041.


E. Appiani, R. Ossola, D. E. Latch, P. R. Erickson, K. McNeill, Aqueous singlet oxygen reaction kinetics of furfuryl alcohol: Effect of temperature, pH, and salt content, Environ. Sci. Processes Impacts 2017, 19, 507-516.


K. McNeill, S. Canonica, Triplet state dissolved organic matter in aquatic photochemistry: Reaction mechanisms, substrate scope, and photophysical properties, Environ. Sci. Processes Impacts 2016, 18, 1381-1399.


E. Appiani, K. McNeill, Photochemical Production of Singlet Oxygen from Particulate Organic Matter, Environ. Sci. Technol. 2015, 49, 3514-3522.

E. Appiani, S. E. Page, K. McNeill, On the use of hydroxyl radical kinetics to assess the number average molecular weight of dissolved organic matter, Environ. Sci. Technol. 2014, 48, 11794–11802.


S. E. Page, J. R. Logan, R. M. Cory, K. McNeill, Evidence for dissolved organic matter being the primary source and sink of photochemically produced hydroxyl radical in arctic surface waters Environ. Sci. Processes & Impacts 2014, 807–822.


C. M. Sharpless, M. Aeschbacher, S. E. Page, J. Wenk, M. Sander, K. McNeill, Photooxidation-Induced Changes in Optical, Electrochemical and Photochemical Properties of Humic Substances Environ. Sci. Technol. 2014, 48, 2688–2696.


S. E. Page, G. W. Kling, M. Sander, K. H. Harrold, J. R. Logan, K. McNeill, R. M. Cory, Dark formation of hydroxyl radical in arctic soils and surface waters, Environ. Sci. Technol. 2013, 47, 12860–12867.


J. Wenk, S. N. Eustis, K. McNeill, S. Canonica, Quenching of excited triplet states by dissolved natural organic matter, Environ. Sci. Technol., 2013, 47, 12802–12810.


C. K. Remucal, R. M. Cory, M. Sander, K. McNeill, Low Molecular Weight Components in an Aquatic Humic Substance as Characterized by Membrane Dialysis and Orbitrap Mass Spectrometry Environ. Sci. Technol., 2012, 46, 9350–9359.


B. M. Peterson, A. M. McNally, R. M. Cory, J. D. Thoemke, J. B. Cotner, K. McNeill, Spatial and temporal distribution of singlet oxygen in Lake Superior, Environ. Sci. Technol., 2012, 46, 7222–7229.


J. M. Burns, W. J. Cooper, J. L. Ferry, D. W. King, B. P. DiMento, K. McNeill, C. J. Miller, W. L. Miller, B. M. Peake, S. A. Rusak, A. L. Rose, T. D. Waite, Methods for reactive oxygen species (ROS) detection in aqueous environments, Aquat Sci., 2012, 74, 683-734.


S.E. Page, M. Sander, W. A. Arnold, K. McNeill,  Hydroxyl radical formation upon oxidation of reduced humic acids by oxygen in the dark, Environ. Sci. Technol., 2012, 46, 1590–1597.

Photochemistry of amino acids and peptides


Amino acids are central building blocks of life and a key component of the global nitrogen cycle.  The environmental fate processes of amino acids thus play an important role in biogeochemistry, but are as of yet poorly defined.  We have several projects focused on defining the important fate processes of amino-acid based biomolecules in the environment.  These projects cover amino acids at different levels of organization, from individual amino acids to intact proteins and further to protein assemblies in virus capsids.


Representative Recent Publications

C. Chu, D. Stamatelatos, K. McNeill, Aquatic photochemical transformations of natural peptidic thiols: Impact of thiol properties, solution pH, solution salinity and metal ions, Environ. Sci. Processes Impacts, 2017, 19, 1518 - 1527.


C. Chu, P. R. Erickson, R. A. Lundeen, D. Stamatelatos, P. J. Alaimo, D. E. Latch, K. McNeill, Photochemical and non-photochemical transformations of cysteine with dissolved organic matter, Environ. Sci. Technol., 2016, 50, 6363-6373.

R. A. Lundeen, C. Chu, M. Sander, K. McNeill, Photooxidation of the antimicrobial, nonribosomal peptide bacitracin A by singlet oxygen under environmentally relevant conditions, Environ. Sci. Technol. 2016, 60, 8586-8595.

C. Chu, R. A. Lundeen, M. Sander, K. McNeill, Assessing the indirect photochemical transformation of dissolved combined amino acids through the use of systematically designed histidine-containing oligopeptides, Environ. Sci. Technol. 2015, 49, 12798-12807.

C. Chu, R. A. Lundeen, C. K. Remucal, M. Sander, K. McNeill, Enhanced indirect photochemical transformation of histidine and histamine through association with chromophoric dissolved organic matter, Environ. Sci. Technol. 2015, 49, 5511-5519.

E. M.-L. Janssen, K. McNeill, Environmental photoinactivation of extracellular phosphatase and the effects of dissolved organic matter, Environ. Sci. Technol. 2015, 49, 889-896.


A. M. Amado, J. B. Cotner, R. M. Cory, B. L. Edhlund, K. McNeill, Disentangling the interactions between photochemical and bacterial degradation of dissolved organic matter: Amino acids play a central role, Microbial Ecology 2015 DOI:10.1007/s0248-014-0512-4


R. A. Lundeen, E. M.-L. Janssen, C. Chu, K. McNeill, Environmental Photochemistry of Amino Acids, Peptides and Proteins, Chimia 2014, 68, 812-817.


E. M. L. Janssen, P. R. Erickson, K. McNeill, Dual roles of dissolved organic matter as sensitizer and quencher in the photooxidation of tryptophan, Environ. Sci. Technol. 2014, 48, 4916–4924.


R. A. Lundeen, K. McNeill, Reactivity differences of combined and free amino acids: Quantifying the relationship between three-dimensional protein structure and singlet oxygen reaction rates, Environ. Sci. Technol. 2013, 47, 14215–14223.

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