The Guzman group studies processes occurring in environmental interfaces and is interested in research problems of interdisciplinary scope. We are currently investigating photooxidative reactions of organic molecules of environmental relevance to understand the processing of pollutants "on the surface of" and "in" atmospheric aerosols, clouds, and fogs. Some of our recent accomplishments include to have provided comprehensive photochemical and heterogeneous oxidation reaction mechanisms for the processing of dissolved organic matter molecular probes "in" and "on the surface of" aqueous aerosol mimics. The laboratory applies soft ionization methods such as online electrospray ionization mass spectrometry (OESI-MS), multiple chromatographic separations, one and two dimensional nuclear magnetic resonance, and various spectroscopies to contrast the fast oxidation of biomass burning and combustion emissions at the air-water interface versus the air-solid interface. One of our latest environmental chemistry developments is the creation of integrated unmanned aerial systems for environmental monitoring of trace gases. We are also interested on the potential use of photocatalysis for fuel production and to jumpstart a prebiotic chemical cycle related to the origin of life. Because past work has focused on the study of reactions in ice matrices, the laboratory is also experienced in ice chemistry.