Analytical Chemistry/Environmental & Geochemistry

Our research activities focus on atmospheric chemistry, mainly aqueous phase chemistry (clouds, fogs and rain), atmospheric particulate matter and particle droplet interactions. We are also interested in the impact of particle and cloud chemistry on local, regional (public health, visibility, deposition fluxes) and global scale (effects on Earth's radiative budget). All our research relies largely on environmental analytical chemistry and involves field campaigns to collect samples and study processes in situ. Ongoing projects include: The characterization of aerosol, cloud and fog composition. We are especially interested in composition differences related to the droplet or particle size. The goal of these studies is to investigate the processing of atmospheric particles and gases by clouds and fogs: What particles/gases are scavenged? What happens to them in the aqueous phase? What is the net impact of these processes on the atmospheric composition? The characterization of organic matter in the atmosphere. Usually less than 20% of the carbonaceous material in atmospheric particles is known at a molecular lever. We work on developing new analytical techniques to enhance the speciated fraction. We are also characterizing bulk properties of organic matter including its size, its polarity and the presence of functional groups in order to predict the impact on aqueous phase chemistry and on physico-chemical properties like surface tension. Laboratory studies of aqueous phase chemistry involving organic compounds in atmospherically relevant conditions. We are currently evaluating atmospheric organic molecular marker stability. While organic molecular markers are widely used to apportion the source of carbonaceous particles in the atmosphere, surprisingly little is known about their stability and atmospheric lifetimes. Our research investigates the degradation of these molecules in laboratory experiments under conditions simulating atmospheric droplets (haze, clouds, fogs).

"Fog Composition in the Central Valley of California Over Three Decades," P. Herckes, A. Marcotte, Y. Wang and J.L. Collett, , Atmospheric Research, 151, 20-30, 2015. 151 20-30 (2015) "Secondary Organic Aerosol Contributions to PM2.5 in Monterrey, Mexico: Temporal and Seasonal Variation. ," Y. Mancilla, P. Herckes, M. Fraser and A. Mendoza , Y. Mancilla, P. Herckes, M. Fraser and A. Mendoza*, Secondary Organic Aerosol Contributions to PM2.5 in Monterrey, Mexico: Temporal and Seasonal Variation. Atmospheric Research, 153, 348-359, 2015. 153 348-359 (2015) "Fog chemistry at three sites in Norway," Y. Wang, J. Zhang, A.R. Marcotte, M. Karl, C. Dye and P. Herckes, Atmospheric Research 151 72-81 (2015) "Chemical Characterization of Coarse Particulate Matter in the Desert Southwest – Pinal County Arizona, USA," A. L. Clements, M.P. Fraser, N. Upadhyay, P. Herckes, M. Sundblom, J. Lantz and P. Solomon, Atmospheric Pollution Research,5, 52-61, 2014. 5 52-61 (2014) "Characterization of Food-Grade Titanium Dioxide: Presence of Nano-Sized Particles," Y. Yang, K. Doudrick, X. Bi, K. Hristovski, P. Herckes, P. Westerhoff and R. Kaegi, Environmental Science and Technology 48 6391-6400 (2014) "Elemental Composition of PM2.5 in Windblown Dust in Shiprock, New Mexico, a Rural Community Influenced by Industrial Sources," C. Gonzalez-Maddux, A. Marcotte, N. Upadhyay, P. Herckes, Y. Williams, G. Haxel and M. Robinson, Atmospheric Pollution Research 5 511-519 (2014) " Black carbon concentrations and sources in the marine boundary layer of the tropical Atlantic Ocean using four methodologies," K. Pohl, M. Cantwell, P. Herckes and R. Lohmann, Atmospheric Chemistry and Physics 14 7431-7443 (2014) "Quantitative resolution of nanoparticle sizes using single particle inductively coupled plasma mass spectrometry with the K-means clustering algorithm," X. Bi, S. Lee, J.F. Ranville, P. Sattigeri, A. Spanias, P. Herckes and P. Westerhoff, Journal of Analytical Atomic Spectrometry 29 1630-1639 (2014) "Nanoparticle size detection limits by single particle ICP-MS for 40 elements," S. Lee, X. Bi, R. Reed, J. Ranville, P. Herckes and P. Westerhoff., S. Lee, X. Bi, R. Reed, J. Ranville, P. Herckes and P. Westerhoff*. Nanoparticle size detection limits by single particle ICP-MS for 40 elements, Environmental Science and Technology, 48, 10291–10300, 2014. 48 10291-10300 (2014) "Impact of Hydraulic and Carbon Loading Rates of Constructed Wetlands on Contaminants of Emerging Concern (CECs) Removal," F. Sharif, P.Westerhoff and P. Herckes, Environmental Pollution 185 107-115 (2014) "Extraction of carbon nanotubes from complex organic matrices with application to rat lung tissue," K. Doudrick, N. Corson, G. Oberd?rster, A. Eder, P. Herckes, R. Halden and P. Westerhoff, ACS Nano 7 8849-8856 (2013) "Characterization of atmospheric organic matter using size-exclusion chromatography with inline organic carbon detection," Y. Wang, C. Chiu, P. Westerhoff, K.T. Valsaraj and P. Herckes, Atmospheric Environment 68 326-332 (2013) "Source apportionment of aerosol iron in the marine environment using iron isotope analysis," C. Mead, P. Herckes, B.J. Majestic and A. D. Anbar , Geophysical Research Letters 40 10.1002/2013GL057713 (2013) "A review of observations on organic matter in fogs and clouds: origin, processing and fate," P. Herckes, K.T. Valsaraj and J.L. Collett, Jr., Atmospheric Research 132-133 443-449 (2013) "Summertime Characterization of Fine and Coarse Particulate Matter in the Desert Southwest," A. L. Clements, M.P. Fraser, N. Upadhyay, P. Herckes, M. Sundblom, J. Lantz and P. Solomon, Journal of the Air and Waste Management Association 63 764-772 (2013) "Dissolved organic carbon (DOC) and select aldehydes in cloud and fog water: The role of the aqueous phase in impacting trace gas budgets," B. Ervens, Y. Wang, J. Eagar, W.R. Leaitch, A.M. Macdonald, K.T. Valsaraj and P. Herckes, Atmospheric Chemistry and Physics 13 5117-5135 (2013) "Adsorption of N-Nitrosodimethylamine Precursors by Powder and Granular Activated Carbon," D. Hanigan, J. Zhang, P. Herckes, S. Krasner, C. Chen and P. Westerhoff, Environmental Science and Technology 46 12630-12639 (2012) "Carbon Nanotube Quantification in Environmental and Biological Matrices," K. Doudrick, P. Herckes and P. Westerhoff, Environmental Science and Technology 46 12246-12253 (2012) "Beyond nC60: Strategies to identify oxidized fullerene transformation products in aquatic and biological samples," B.F.G. Pycke, T.C. Chao, R.U. Halden, P. Herckes and P. Westerhoff, Analytical and Bioanalytical Chemistry 404 2583-2595 (2012) "Distribution of Polycyclic Aromatic Hydrocarbons in Soils of Urban Transportation Corridors in an Arid Ecosystem.," Y. Marusenko, P. Herckes and S.J. Hall., Water, Air and Soil Pollution 219 473-487 (2011) "Aqueous OH oxidation of ambient organic aerosol and cloud water organics: Formation of highly oxidized products.," A.K.Y. Lee, P. Herckes, W. R. Leaitch, A. M. Macdonald and J. P. D. Abbatt, Geophysical Research Letters 38 L11805 (2011) "Quantification of Fullerenes (C60 and C70) in Commercial Cosmetics," T. M. Benn, P. Westerhoff and P. Herckes, Environmental Pollution 159 1334-1342 (2011) "Solubility and Speciation of Atmospheric Iron in Buffer Systems Simulating Cloud Conditions," N. Upadhyay, B.J. Majestic and P. Herckes, Atmospheric Environment 45 1858-1866 (2011) "Synthetic Musk Emissions from Wastewater Aeration Basins," N. Upadhyay, Q. Sun, J.O. Allen, P. Westerhoff and P. Herckes, Water Research 45 1071-1078 (2011) "Speciation of Mercury (II) and Methylmercury in Cloud and Fog Water," D.R. Bittrich, D.E. Armstrong, S.P. Chadwick, C.L. Babiarz, H. Manolopoulos, A.P.Rutter, J.J. Schauer, J. Collett and P. Herckes., Aerosol and Air Quality Research 11 161-169 (2011) "Chemical Speciation of PM2.5 and PM10 in South Phoenix, Arizona.," N. Upadhyay, A. Clements, M. Fraser and P. Herckes. , Journal of the Air and Waste Management Association 61 302-310 (2011) "Evaluation of extraction methods for the quantification of aqueous fullerenes in urine," T.M. Benn, B.F.G. Pycke, P. Herckes, P. Westerhoff and R.U. Halden, Analytical and Bioanalytical Chemistry 399 1631-1639 (2011) "Characterization of PM2.5 collected during broadcast and slash-pile prescribed burns of predominately ponderosa pine forests in northern Arizona," M. Robinson, M. Zhao, L. Zack, C. Brindley, L. Portz, M. Quarterman; X. Long and P. Herckes, Atmospheric Environment 45 2087-2094 (2011) "Characterization and LC-MS/MS based quantification of hydroxylated fullerenes (fullerols). ," T.C. Chao, G. Song, P. Westerhoff, P. Herckes and R. Halden, Analytical Chemistry 83 1777-1783 (2011) "Strategies for quantifying C60 fullerenes in environmental and biological samples and implications for studies in environmental health and ecotoxicology," B.F.G. Pycke, T.M. Benn, P. Herckes, P. Westerhoff and R.U. Halden, Trends in Analytical Chemistry 30 44-57 (2011)

"N-nitrosodimethylamine occurrence, formation and cycling in clouds and fogs.," J.W. Hutchings, B. Ervens, D. Straub and P. Herckes, Environmental Science and Technology 44 8128-8133 (2010)