Article
Engineering, Environmental
Dihui Chen, Xiaohong Yao, Chak Keung Chan, Xiaomeng Tian, Yangxi Chu, Simon Leslie Clegg, Yanjie Shen, Yang Gao, Huiwang Gao
Summary: Alkaline gases like NH3 and amines are important in neutralizing acidic particles in the atmosphere. This study found that the competition of DMA and NH3 on acidic aerosols follows thermodynamic equilibria and is sensitive to the DMA/NH3 molar ratio.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Chemical
Hang Thi Nguyen, Gudrun Svana Hilmarsdottir, Tumi Tomasson, Sigurjon Arason, Maria Gudjonsdottir
Summary: This study investigated the changes in quality of protein and non-protein nitrogen compounds during industrial fishmeal processing. The results showed that the quality of the final fishmeal products depended on the fish species being processed and different processing steps resulted in different properties in each stream.
Article
Food Science & Technology
Sarah Todeschini, Veronique Perreault, Charles Goulet, Melanie Bouchard, Pascal Dube, Yvan Boutin, Laurent Bazinet
Summary: The study revealed that pH had a significant impact on the odorous content of HMH, with higher concentrations of specific compounds detected at pH 10 compared to pH 7, while the impact on the most potent odor-active compounds of HMH was opposite; overnight stirring with or without nitrogen had no effect on the odorous content; deaerator treatment was more effective in removing TMA and DMA at pH 10, but less effective for the most potent odor-active compounds of HMH.
Article
Chemistry, Analytical
Congchao You, Tien Ho, Victor Rucker, Jerry Yeh, Lin Wang
Summary: A simple and universal headspace gas chromatography with flame ionization detection (HS-GC-FID) method is described for accurate quantification of volatile amines in pharmaceuticals. The addition of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an additive improves the detectability and method accuracy of residual volatile amines in pharmaceutical products. Method validation shows acceptable linearity, limit of detection, limit of quantitation, solution stability, precision, and robustness.
ANALYTICAL METHODS
(2023)
Article
Chemistry, Multidisciplinary
Weina Zhang, Jie Zhong, Qiuju Shi, Lei Gao, Yuemeng Ji, Guiying Li, Taicheng An, Joseph S. Francisco
Summary: The study reveals that at high sulfuric acid concentrations, amines quickly form ammonium salts, while at low sulfuric acid concentrations, they mainly produce unstable ionic pairs through hydrolysis reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Inorganic & Nuclear
Junyi Li, Zoltan Szabo, Mats Jonsson
Summary: This study identified the ternary uranyl-peroxo-chloro and uranyl-peroxo-bromo complexes using spectroscopy techniques. The uranyl-peroxo-chloro complex was found to be more stable than the uranyl-peroxo-bromo complex, which transforms into studtite at high uranyl and H2O2 concentrations. Studtite was also found to dissolve under high ionic strength conditions, suggesting it may not be a stable solid phase under very saline conditions. The uranyl-peroxo-bromo complex was shown to facilitate H2O2 decomposition via reactive intermediates.
INORGANIC CHEMISTRY
(2022)
Article
Engineering, Electrical & Electronic
Kuibo Lan, Shuaiyan Liu, Zhi Wang, Junqing Wei, Guoxuan Qin
Summary: In this study, a high-performance TMA sensor was developed using a pyramid substrate structure and olfactory receptor-derived peptides (ORPs) chemically connected to single-walled carbon nanotubes (SWCNTs). The sensor was capable of detecting gaseous TMA with a concentration as low as 0.01 ppt, and showed significantly improved responsivity compared to sensors on flat substrates. Selectivity and repeatability measurements confirmed the excellent sensitivity and stability of the sensor for TMA detection. The potential applications of these TMA sensors include food safety, diseases monitoring, and environmental protection.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Physical
Yang Chen, Licheng Zhong, Siyue Liu, Haotian Jiang, Jiayu Shi, Yuqi Jin, Xueming Yang, Wenrui Dong
Summary: We used the OH laser-induced fluorescence (LIF) method to measure the kinetics of CH2OO reacting with two abundant amines in the atmosphere, specifically dimethylamine and trimethylamine. We found that both reactions exhibit a negative temperature dependence and identified factors such as the electronegativity of the co-reactant atom and the dissociation energy of fragile covalent bonds that play a role in these reactions. These reactions can contribute to the sink of amines and Criegee intermediates and the formation of secondary organic aerosol under certain circumstances.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Fumie X. Sunahori, Tony C. Smith, Dennis J. Clouthier
Summary: The AlCH2 free radical has been spectroscopically identified for the first time, and its spectroscopic properties and geometries have been studied in detail.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Agriculture, Multidisciplinary
Hana Lee, Xin Liu, Jin-Pyo An, Yu Wang
Summary: This study investigates the inhibitory effects of polymethoxyflavones (PMFs) on enzymes involved in the production of trimethylamine (TMA) and trimethylamine-N-oxide (TMAO). The findings suggest that specific structural features of PMFs contribute to their interactions with enzymes. Furthermore, the study introduces a novel model system to assess and compare the inhibitory effects of PMFs on TMAO production. These findings could potentially lead to the development of novel therapeutic approaches to manage cardiovascular disease (CVD).
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Chemistry, Analytical
Yue Xing, Le-Xi Zhang, Meng-Xiao Chong, Yan-Yan Yin, Cheng-Tao Li, Li-Jian Bie
Summary: Pure ZnO and carbon-doped ZnO hollow spheres were successfully synthesized via a hydrothermal-calcination process. The carbon doping introduced abundant defects in the mesoporous ZnO hollow spheres, leading to enhanced gas sensing performance towards dimethylamine. The response of ZnO-600 towards 200 ppm dimethylamine was significantly higher than that of Pure ZnO and ZnO-500, and the detection limit was as low as 108 ppb. The unique mesoporous microstructure and rich defects induced by in-situ carbon doping contributed to the improved sensing performance of ZnO-600.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Chemistry, Physical
Michael F. Vansco, Meijun Zou, Ivan O. Antonov, Krupa Ramasesha, Brandon Rotavera, David L. Osborn, Yuri Georgievskii, Carl J. Percival, Stephen J. Klippenstein, Craig A. Taatjes, Marsha Lester, Rebecca L. Caravan
Summary: By combining experimental data with high-level theory, the study explores the conformer dependence of the reaction of acetaldehyde oxide with dimethylamine, revealing a strong dependence on the reaction rate. The results support the theoretically predicted insertion mechanism and the formation of amine-functionalized hydroperoxide as the reaction product. The study predicts a significant difference in reaction rate between anti-CH3CHOO and syn-CH3CHOO due to their different energetic mechanisms.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Instruments & Instrumentation
Christopher J. Thompson, Neal B. Gallagher, Kendall D. Hughey, Megan K. Dunlap, Tanya L. Myers, Timothy J. Johnson
Summary: A spectral analysis tool called SpecQuant has been developed to identify and quantify gas-phase species from complex infrared spectra. It can handle both reference and experimental data with varying resolution and instrumental lineshape. The software uses classical least squares model and reference spectra to determine the mixing ratio of each species along with its estimation error. SpecQuant also provides visual inspection of the fit and residuals by displaying the calculated mixing ratio versus experimental data for each analyte.
APPLIED SPECTROSCOPY
(2023)
Article
Biochemical Research Methods
Fangling Wu, Shutong Yang, Xinhua Dai, Liancheng Gu, Fuxing Xu, Xiang Fang, Shaoning Yu, Chuan-Fan Ding
Summary: The study successfully discriminated three positional isomers of 2-ABP, 3-ABP, and 4-ABP simultaneously using ion mobility spectrometry and quantum mechanical calculations. The method showed clear advantages in isomer discrimination and conformation analysis, providing potential applications in chemistry and pharmaceutical sciences.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2021)
Article
Chemistry, Analytical
Kas J. Houthuijs, Giel Berden, Udo F. H. Engelke, Vasuk Gautam, David S. Wishart, Ron A. Wevers, Jonathan Martens, Jos Oomens
Summary: Infrared ion spectroscopy (IRIS) is increasingly used as an analytical tool for small-molecule identification in conjunction with mass spectrometry (MS). However, directly translating an IR spectrum to a molecular structure remains challenging due to the lack of reference libraries. To solve this issue, an in silico library of vibrational spectra of common MS adducts of over 4500 compounds has been introduced. This library can be queried with experimental IR spectra, enabling accurate identification of metabolites.
ANALYTICAL CHEMISTRY
(2023)
Article
Engineering, Environmental
Lin Du, Li Xu, Kun Li, Christian George, Maofa Ge
Summary: Anthropogenic air pollutants play a role in the formation of biogenic secondary organic aerosols (SOA), but this interaction is poorly understood. This study investigated the formation of SOA through chemical interactions between anthropogenic SO2, NH3, and O3 and biogenic S-caryophyllene. The results showed that while SO2 enhanced SOA formation, NH3 weakened this enhancing effect when coexisting with SO2. NH3 neutralized the particle acidity generated by SO2 oxidation, resulting in suppressed formation of certain products. This study highlights the importance of considering NH3 when evaluating the effects of SO2 on SOA formation via anthropogenic-biogenic interactions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Ruixue Wang, Kun Li, Jianlong Li, Narcisse T. Tsona, Wenxing Wang, Lin Du
Summary: Heterogeneous reactions of acidic gases on mineral dust particles affect the atmosphere, soil, and water environments during long-distance transport. However, the interactions of inorganic and organic acidic gases with aerosols are still poorly understood. In this study, the reactions of sulfur dioxide (SO2) and acrylic acid on titanium dioxide (TiO2) particles were investigated under different conditions. The results reveal the interaction of different acidic gases on the surface of particles and advance the understanding of the heterogeneous reaction of trace gases in complex atmospheric environments.
ACS EARTH AND SPACE CHEMISTRY
(2023)
Article
Chemistry, Physical
Menglan Xiao, Dawei Han, Xueqin Yang, Narcisse Tsona Tchinda, Lin Du, Yucong Guo, Yuechang Wei, Xiaolin Yu, Maofa Ge
Summary: This study constructs a Pt/Ni-CeO2 catalyst via Ni doping, which enhances the catalytic performance of toluene and improves water- and SO2-tolerance. The introduction of Ni induces the generation of abundant oxygen vacancies, facilitating the activation of oxygen species, while the formation of Pt-NiO interface structure restrains the adsorption of water and SO2 molecules.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Correction
Chemistry, Physical
Eva R. Kjaergaard, Emil Vogt, Kristian H. Moller, Ole John Nielsen, Henrik G. Kjaergaard
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jing Chen, Joseph R. Lane, Henrik G. Kjaergaard
Summary: The atmospheric oxidation of dimethyl sulfide and other emitted sulfur species can lead to the formation of different sulfur-centered radicals. We performed computational investigations on the reactions of these radicals with peroxy radicals. The results show that certain sulfur-centered radicals form short-lived peroxide intermediates, while others form stable peroxide products. The valence of the sulfur atom plays a crucial role in determining the reaction outcome.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jeppe Langeland, Nanna Falk Christensen, Emil Vogt, Christina Kjaer, Thomas Toft Lindkvist, Steen Brondsted Nielsen, Henrik G. Kjaergaard
Summary: This paper investigates the bioluminescence of fireflies, click beetles, and railroadworms, specifically focusing on the role of oxyluciferin in color variation. Experimental and theoretical study of the absorption and emission spectra of 5,5-dimethyl-oxyluciferin anion (keto form) at different temperatures is presented, along with fluorescence-based lifetime measurements. The results reveal the involvement of various vibrational modes in Franck-Condon progressions, with reduced spectral congestion at lower temperatures.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Engineering, Environmental
Jian-Lu Duan, Jing-Ya Ma, Xiao-Dong Sun, Xiao-Yu Liu, Yue Wang, Lin Du, Peng-Fei Xia, Xian-Zheng Yuan
Summary: Antibiotic resistance is a global health challenge. This study reveals how bubbles can spread antibiotic resistance genes and interact with the extracellular matrix in the aquatic environment, providing new insights into the dissemination of antibiotic resistance.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Emil Vogt, Iren Simko, Attila G. Csaszar, Henrik G. Kjaergaard
Summary: This study calculated the intramolecular vibrational transition wavenumbers and intensities in different vibrational regions of the water dimer's spectrum, and computed the rotational-vibrational spectrum in the Delta v(OH) = 2 region. The calculated spectrum was obtained by combining results from a full-dimensional vibrational model and a reduced-dimensional vibrational-rotational-tunneling model. The Delta v(OH) = 2 spectral region is characterized by multiple vibrational-rotational-tunneling sub-bands, which contribute to the rich features in the spectrum.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Eva Kjaergaard, Kristian Moller, Henrik Kjaergaard
Summary: This study uses advanced theoretical methods to investigate the oxidation pathways and reaction rates of hydroperoxy amides in the atmosphere, and identifies the oxidation products of hydroperoxy amides under specific conditions. The results indicate that hydroperoxy amides predominantly form imides and have slow reaction rates due to structural constraints.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Eva R. Kjaergaard, Kristian H. Moller, Torsten Berndt, Henrik G. Kjaergaard
Summary: Autoxidation is an important oxidation pathway in the atmosphere for various compounds, including isoprene and monoterpenes. This study reveals that autoxidation also plays a dominant role in the oxidation of nonhydrocarbons like dimethyl sulfide and trimethylamine. The research focuses on the autoxidation of triethylamine and provides theoretical calculations and experimental evidence to support the efficient autoxidation in this compound.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Environmental Sciences
Sara E. Murphy, John D. Crounse, Kristian H. Moller, Samir P. Rezgui, Nicholas J. Hafeman, James Park, Henrik G. Kjaergaard, Brian M. Stoltz, Paul O. Wennberg
Summary: Through experiments, we found a new ROOR substance in the reaction of RO2 center dot and HO2 center dot, which has a gas-phase branching fraction of 23%. We also observed that the ratio of the rate coefficient for the reaction of RO2 center dot + RO2 center dot to that of RO2 center dot + HO2 center dot is approximately 0.22.
ENVIRONMENTAL SCIENCE-ATMOSPHERES
(2023)
Article
Environmental Sciences
Minglan Xu, Narcisse Tsona Tchinda, Jianlong Li, Lin Du
Summary: Saccharides are important components of sea spray aerosol, and their mechanism of transfer from seawater to aerosol is still debated. This study validated the transfer of soluble saccharides and showed that they can promote the production of aerosol particles, while an insoluble fatty acid film reduces aerosol production.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Zhaomin Yang, Kun Li, Narcisse T. Tsona, Xin Luo, Lin Du
Summary: Our study investigates the effect of sulfur dioxide (SO2) on aerosol formation and composition. We found that the presence of SO2 leads to a significant increase in particle number concentration, mainly due to the formation of sulfuric acid (H2SO4) from the reactions between stabilized Criegee intermediates and SO2. Additionally, we observed the presence of organosulfates (OSs) which are likely formed through heterogeneous reactions between oxygenated species and H2SO4. These OSs have been previously identified in field studies but their sources and structures were unknown. We also found that the observed OSs are less volatile than their precursors and contribute to particle formation and growth in the presence of SO2.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Christina Kjaer, Emil Vogt, Jeppe Langeland, Nanna Falk Christensen, Thomas Toft Lindkvist, Henrik G. Kjaergaard, Steen Brondsted Nielsen
Summary: Recent developments in fluorescence spectroscopy allow for the measurement of absorption and dispersed fluorescence spectra of isolated molecular ions at low temperatures. Lower temperatures provide narrower spectra and better information on vibronic features. Experiments were conducted on oxazine dyes cooled to around 100 K, and the results showed small Stokes shifts and broader spectra for the darrow-red cations compared to other ionic dyes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)