Free radicals play an important role in the oxidizing power of polluted air, the development of aging-related diseases, the formation of ozone, and the production of secondary particulate matter. The high variability of peroxyl radical concentration has prevented the detection of possible trends or distributions in the concentration of free radicals. We present a new method, free radical reaction combined with liquid chromatography photodiode array detection, for identifying and quantifying peroxyl radicals in polluted air. Functionalized graphene was used for loading peroxyl radicals and reactive molecules in air sampling system, which can facilitate reaction kinetics (charge transfers) between peroxyl radicals and reaction molecules. Separation was performed with and without a preliminary exposure of the polluted air sample to reactive molecule(s) system. The integral chromatographic peak areas before and after air sampling are used to quantify the atmospheric peroxyl radicals in polluted air. The utility of the new technique was tested with measurements carried out in the field.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jssc.201701152 | DOI Listing |
Environ Sci Technol
January 2025
Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States.
This study quantifies the contribution of the HO-dependent pathway to hydroxyl radical (OH) production from the photolysis of dissolved organic matter (DOM). OH formation rates were cross-validated using benzoate and terephthalate as probe compounds for diverse DOM sources (reference isolates and whole waters). Catalase addition revealed that the HO-dependent pathway accounts for 10-20% of the total OH production in DOM isolate materials, but no significant correlation was observed between ambient iron (Fe) concentrations and HO-dependent OH formation.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China.
The most well-known hydroxyl radical (OH)-generating system is the classic iron-mediated Fenton reaction. Thiourea has been considered as an efficient OH scavenger and is frequently used to study the role of OH in various biochemical and medical research studies. Here we found that the highly reactive OH can be produced from thiourea and HO through a metal-independent pathway, as measured by electron spin resonance (ESR) secondary radical spin-trapping and fluorescent methods.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Department of Stem Cell and Regenerative Medicine and Medical Biotechnology, Centre for Interdisciplinary Research, D. Y. Patil Education Society, Kolhapur, Maharashtra, India.
A straightforward one-step hydrothermal method is introduced for synthesizing highly efficient red fluorescence carbon dots (R-CQDs), utilizing Heena leaf (Lawsonia inermis) powder as the carbon precursor. The resulting R-CQDs exhibit excitation at 540 nm and emission at 675 nm, a high absolute photoluminescence (PL) with quantum yield of 40% in ethanol. Various physicochemical characterization was employed to confirm successful formation of R-CQDs including UV-Vis Spectroscopy, Fourier Transform Infrared (FT-IR) Spectroscopy, X-ray diffraction Spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Sunlight irradiation of dissolved organic matter (DOM) in surface water results in the production of photochemically produced reactive intermediates (PPRIs). This process is inevitably influenced by co-existing metal ions in aquatic environments; However, the underlying mechanism remains unclear. In this study, the effect of co-existing copper ion (Cu) on PPRIs produced by irradiation of DOM was systematically investigated, because Cu is a typical redox transient cation and has strong affinity to DOM.
View Article and Find Full Text PDFEnviron Geochem Health
January 2025
Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, 46300, Pakistan.
Although the use of biochar as an adsorbent for the removal of various pollutants from wastewater is well established, the use of biochar/modified biochar for the scavenging of antibiotics from aqueous media in the Fenton-like system receives less attention. The highest kasugamycin (KSM) adsorption capacity (5.0 mg g) was obtained from the pristine biochar at the lowest initial pH of 3 in Fenton-like system.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!