Photochemical Oxidation Research Articles

Unveiling the Environmental Impacts of Concentrated Latex Manufacturing in Sri Lanka through a Life Cycle Assessment

Sri Lanka is a top producer of premium quality concentrated latex (CL), which becomes a base material for dipped rubber products such as gloves and condoms. The processing of CL is resource-intensive, requiring significant amounts of energy, fuel, water, and chemicals. This process leads to various environmental issues such as wastewater pollution, malodor, and greenhouse gas emissions. Several environmental life cycle assessments (LCA) have been conducted at international and local levels to address the aforesaid issues. However, LCAs encapsulating different environmental impact areas on CL processing in Sri Lanka are absent. The study revealed that electricity usage was the main hotspot of the environmental burden, significantly impacting abiotic depletion (fossil fuels), global warming potential, ozone layer depletion, photochemical oxidation, and acidification. Heavy reliance on coal in the Sri Lankan power grid was identified as the root of this trend. The study suggested two viable options to mitigate the environmental impact: installing inverters to centrifuge separators and solar systems in the factories. The second option was deemed more effective, reducing acidification, photochemical oxidation, and global warming potential by approximately 37%, 36%, and 28%, respectively. Relevant officials may immediately consider these improvement options and collaborate to pave the way to a sustainable natural rubber industry.

Techno-Economic and Life Cycle Assessment of a Small-Scale Integrated Biorefinery for Butyric-Acid Production in Chile

This study evaluates the techno-economic and environmental feasibility of a small-scale biorefinery in Chile’s La Araucanía Region, which utilizes wheat straw as feedstock to produce butyric acid using Clostridium tyrobutyricum. Two scenarios were considered; the standalone wheat straw biorefinery and its integration with the anaerobic digestion of pig manure for biogas production, coupled with a cogeneration system, using the xylo-oligosaccharides and lignin obtained in the pretreatment. The simulations were carried out using Aspen Plus, while the Aspen Process Economic Analyzer was used to perform the economic evaluation. The simulation results were validated with experimental data from the literature. An economic assessment was performed considering the different processes involved. A cradle-to-gate life-cycle analysis (LCA) was also applied to evaluate the different environmental impacts. Both studied scenarios were economically feasible, with the highest butyric acid production cost being USD 2.97/kgbutyricacid; however, this value is still higher compared to corn-based biorefineries. Annexed biogas production increased the costs and was less economically attractive. Nonetheless, the integrations with biogas production had lower environmental impacts, except in the photochemical oxidant formation category, which was higher because of the combustion gases obtained by the cogeneration system. A lower carbon footprint (23.5 kg CO2-eq. per ton of wheat straw) was obtained for the scenario including biogas production.

Lignin valorization from birch and pine wood for production of ethylene and propylene in Mexico: Conceptual design, life cycle assessment, and energy optimization

Biorefineries require lignin valorization for replacing the largest petrochemicals worldwide produced. However, the lignin biorefinery needs further investigation to determine its feasibility. This work aims to develop the conceptual design, Life Cycle Assessment (LCA), and energy optimization of a lignin biorefinery based on birch and pine wood in Mexico. Propylene and ethylene were the main products. Two optimization approaches were used. The results revealed that the energy consumption was reduced by 59–78 % for the different optimized separation processes. Consequently, for the base case, the climate change impact was reduced from 557 to 462 kt CO2 eq/h (a 17 % reduction), non-renewable energy from 6800 TJ to 5240 TJ/h (23 %), photochemical oxidation from 22.7 to 17.9 t C2H4 eq/h (21 %), and fossil scarcity from 192 to 157 kt oil eq/h (18 %). Therefore, we demonstrate that the environmental performance is impacted by energy optimization, and this impact can be measured using the LCA.

The Environmental Impact of Leachate Processing Installations: Life Cycle Assessment (LCA) Study

This study aims to analyze waste management in the face of population growth and increasing human activity. As the population continues to grow and human activities intensify, the proper management of waste becomes crucial to safeguarding the environment. In this context, leachate treatment through the Leachate Treatment Plant (LTP) emerges as a key element in protecting the environment from the negative impacts of leachate. The Life Cycle Assessment (LCA) method serves as a valuable tool for analyzing the environmental implications of LTPs and aiding in sustainable decision-making. The research process commences with gathering essential data and constructing an inventory related to energy use, greenhouse gas emissions, water pollution loads, and the utilization of natural resources. Through the gate-to-gate approach using the SimaPro application with the CML-IA Baseline method, the environmental impacts are quantified. The study reveals the significant impacts of Global warming (3.03E-08 Pt), Photochemical Oxidation (3.70E-09 Pt), Human toxicity (2.09E-09 Pt), and Eutrophication (1.87E-06 Pt). Eutrophication stands out as the most prominent impact of wastewater treatment. The resultant eutrophication impact predominantly originates from the Biological Oxygen Demand (BOD) pollutant component, mainly generated from the equalization tub unit and constructed wetland. Furthermore, the control tank emerges as the primary source of the dominant pollutant.

Enhancement mechanism of Y-doped Ce1−xYxO2 for photocatalytic-assisted chemical-mechanical polishing

Photocatalytic-assisted chemical-mechanical polishing (PCMP) is an ultra-precision machining method which combines photocatalytic technology with chemical-mechanical polishing (CMP) technology. CeO2 has unique physicochemical properties (tribological properties and photochemical oxidation activity) and is applied to industrial fields extensively. In this paper, a series of Ce1−xYxO2 nanoparticles with controlled size and shape were produced by the molten salt method. SEM images show that Ce1−xYxO2 nanoparticles are nearly spherical with a size of about 113–148 nm. Ion doping can adjust the defect concentration and further enhance the chemical activity of samples. XPS spectra show that doping is beneficial to improve the concentration of Ce3+ and oxygen vacancy. In this way, the photocatalytic activity of CeO2 nanoparticles can be improved. Quartz glasses were polished by synthetic Ce1−xYxO2 nanoparticle polishing solution, where x is the doping amount. The results show that the material removal rate (MRR) of Ce0.95Y0.05O2 abrasives in PCMP was increased by 34.5%. The PCMP mechanism of CeO2 nanoparticles is further discussed. Ultraviolet irradiation increased the reactive sites on the surface of Ce1−xYxO2 nanoparticles, making them have better chemical activity. The hydration layer and Ce-O-Si bond on the surface of quartz glass are formed more easily, thus improving the material removal rate.

Impact of Atmospheric Conditions and Source Identification of Gaseous Polycyclic Aromatic Hydrocarbons (PAHs) during a Smoke Haze Period in Upper Southeast Asia.

Gaseous polycyclic aromatic hydrocarbons were measured in northern Thailand. No previous studies have provided data on gaseous PAHs until now, so this study determined the gaseous PAHs during two sampling periods for comparison, and then they were used to assess the correlation with meteorological conditions, other pollutants, and their sources. The total concentrations of 8-PAHs (i.e., NAP, ACY, ACE, FLU, PHE, ANT, FLA, and PYR) were 125 ± 22 ng m-3 and 111 ± 21 ng m-3, with NAP being the most pronounced at 67 ± 18 ng m-3 and 56 ± 17 ng m-3, for morning and afternoon, respectively. High temperatures increase the concentrations of four-ring PAHs, whereas humidity and pressure increase the concentrations of two- and three-ring PAHs. Moreover, gaseous PAHs were estimated to contain more toxic derivatives such as nitro-PAH, which ranged from 0.02 ng m-3 (8-Nitrofluoranthene) to 10.46 ng m-3 (1-Nitronaphthalene). Therefore, they could be one of the causes of local people's health problems that have not been reported previously. Strong correlations of gaseous PAHs with ozone indicated that photochemical oxidation influenced four-ring PAHs. According to the Pearson correlation, diagnostic ratios, and principal component analysis, mixed sources including coal combustion, biomass burning, and vehicle emissions were the main sources of these pollutants.

전과정평가(LCA)를 이용한 EPS(Electric Power Steering)에 대한 환경영향 평가 연구

This study was quantified using LCA about EPS limited system boundary from raw material extraction until it leaves the factory and assessed six environmental impact categories; Abiotic depletion; Acidification; Eutrophication; Global warming; Ozone layer depletion; and Photochemical oxidants creation. The contributions of raw material extraction to the six environmental impact categories were determined to be as follows:Abiotic depletion 85.2%, Acidification 93.8%, Eutrophication 89.7%, Global warming 86.3%, Ozone layer depletion 99.5%, and Photochemical oxidants creation 93.1%. Sensitivity analysis was performed for data and assumptions to confirm the results reliability of this study. The results of this study confirmed that raw material extraction stage and aluminum material part is the most important environmental impact factors in EPS.

Modeling the Weak pH Dependence of Proton-Coupled Electron Transfer for Tryptophan Derivatives.

The oxidation of tryptophan (Trp) is an important step in many biological processes and often occurs by sequential or concerted proton-coupled electron transfer (PCET). The apparent rate constants for the photochemical oxidation of two Trp derivatives in water have been shown to be pH-independent at low pH and to exhibit weak pH dependence at higher pH. Herein, these systems are investigated with a general, multi-channel model that includes sequential and concerted mechanisms as well as various proton donors and acceptors. This model can reproduce the kinetic data for both Trp derivatives with physically meaningful parameters and suggests that the weak pH dependence may arise from the competition between OH- and H2O as proton acceptors in concerted PCET. Deprotonation of an ammonium group for one of the systems leads to a more complex pH dependence at higher pH. This work demonstrates the importance of considering multiple competing channels for the analysis of the pH dependence of apparent PCET rate constants.

Photoinduced Destruction of Complex Cyanides Using Quasi-Monochromatic UVC Radiation of a KrCl Excilamp (222 nm)

The kinetic regularities of photochemical oxidation of stable complex cyanides (hexacyanoferrates) with persulfate (oxidizing system {UV/S2O}) and hydrogen peroxide (oxidizing system {UV/H2O2}) under the influence of quasi-monochromatic UVC radiation from a KrCl excilamp (222 nm) have been studied. According to the efficiency and rate of the destruction of the target compound, the oxidizing systems under study can be arranged in the following series: {UV/S2O2-8} {UV/H2O2} {UV}. The effective destruction of hexacyanoferrates at micromolar concentrations (≤47 μM) to nontoxic and biodegradable compounds in the combined {UV/S2O2-8} system is due to the high oxidizing ability of reactive oxygen species formed as a result of persulfate photolysis.

Development and application of a nitrogen oxides analyzer based on the cavity attenuated phase shift technique

Nitrogen oxides (NOx) are crucial in tropospheric photochemical ozone (O3) production and oxidation capacity. Currently, the widely used NOx measurement technique is chemiluminescence (CL) (CL-NOx), which tends to overestimate NO2 due to atmospheric oxidation products of NOx (i.e., NOz). We developed and characterized a NOx measurement system using the cavity attenuated phase shift (CAPS) technique (CAPS-NOx), which is free from interferences with nitrogen-containing species. The NOx measured by the CAPS-NOx and CL-NOx analyzers were compared. Results show that both analyzers showed consistent measurement results for NO, but the NO2 measured by the CAPS-NOx analyzer (NO2_CAPS) was mostly lower than that measured by the CL-NOx analyzer (NO2_CL), which led to the deviations in O3 formation sensitivity regime and Ox (= O3 + NO2) sources (i.e., regional background and photochemically produced Ox) determined by the ozone production efficiencies (OPE) calculated from NO2_CL and NO2_CAPS. Overall, OPE_CL exceeded OPE_CAPS by 18.9%, which shifted 3 out of 13 observation days from the VOCs-limited to the transition regime when judging using OPE_CL, as compared to calculations using OPE_CAPS. During the observation period, days dominated by regional background Ox accounted for 46% and 62% when determined using NO2_CL and NO2_CAPS, respectively. These findings suggest that the use of the CL-NOx analyzer tends to underestimate both the VOCs-limited regime and the regional background Ox dominated days. The newly built CAPS-NOx analyzer here can promote the accurate measurement of NO2, which is meaningful for diagnosing O3 formation regimes and Ox sources.

Measurement Report: Investigation on the sources and formation processes of dicarboxylic acids and related species in urban aerosols before and during the COVID-19 lockdown in Jinan, East China

Abstract. Dicarboxylic acid (diacid) homologs are essential indicators of secondary organic aerosols (SOA) that exert a considerable influence on climate changes and atmospheric chemistry. However, their sources and formation processes are poorly understood, leading to uncertainty in predicting the climate effect of SOA. A substantial drop in anthropogenic emissions during the COVID-19 lockdown (LCD) provides a “controlled experiment” to explore the effects of LCD measures and meteorological conditions on SOA. Here we investigated the difference in molecular distributions and stable carbon isotopic compositions (δ13C) of diacid homologs in PM2.5 before and during the LCD. We found that the concentration and contribution of diacid homologs during the LCD were higher than before the LCD, indicating that the enhanced secondary oxidation could offset the reduction in anthropogenic emissions during the LCD. A higher oxalic acid (C2) / diacid ratio and more positive δ13C values of major diacids during the LCD suggested more aged organic aerosols. The enhanced C2 and related species during the LCD were mainly derived from the promoted gaseous photochemical oxidation by the higher oxidants and stronger solar radiation. However, C2 and related species before the LCD were dominantly derived from the aqueous oxidation of α-dicarbonyls depending on relative humidity and liquid water content. The increased δ13C values of C2 and other major diacids along with the high ratios of C2 / glyoxal, C2 / methylglyoxal, and C2 / diacid confirmed an isotopic fractionation effect during the oxidation process of precursors. Our results indicate that atmospheric pollution treatment depends on a balanced strategy and a coordinated effort to control multiple pollutants.

Degradation of Pesticides Using Semiconducting and Tetrapyrrolic Macrocyclic Photocatalysts-A Concise Review.

Exposure to pesticides is inevitable in modern times, and their environmental presence is strongly associated to the development of various malignancies. This challenge has prompted an increased interest in finding more sustainable ways of degrading pesticides. Advanced oxidation processes in particular appear as highly advantageous, due to their ability of selectively removing chemical entities form wastewaters. This review provides a concise introduction to the mechanisms of photochemical advanced oxidation processes with an objective perspective, followed by a succinct literature review on the photodegradation of pesticides utilizing metal oxide-based semiconductors as photosensitizing catalysts. The selection of reports discussed here is based on relevance and impact, which are recognized globally, ensuring rigorous scrutiny. Finally, this literature review explores the use of tetrapyrrolic macrocyclic photosensitizers in pesticide photodegradation, analyzing their benefits and limitations and providing insights into future directions.

Integrating ex-ante and prospective life-cycle assessment for advancing the environmental impact analysis of emerging bio-based technologies

Unlike the fossil-based alternatives, many emerging bio-based technologies are still at the early lab or pilot scale and are not representative of optimized industrial conditions. This makes a robust comparison of their environmental performances via life-cycle assessment (LCA) challenging. We propose a framework to combine scaling-up projections of early-stage technologies (ex-ante LCA) with the influence of future socio-economic scenarios (prospective LCA), using a range of new bio-based polymers produced from forest residues as case study. The combined framework takes a step-by-step approach in modifying process inventories and projecting them to a future industrial scale for the environmental impact assessment. In our case study, the climate change impact from lab-scale processes decreases from 105–471 kg CO2-eq./kg of polymer to 9–14 kg CO2-eq./kg after the application of ex-ante LCA, with the highest reduction (83 %) coming from identified process synergies (e.g., solvent recovering). Combining the ex-ante and prospective LCA additionally reduces the impact up to 56 % by 2050, relative to ex-ante LCA results only. Other environmental impacts decrease as well, particularly freshwater eutrophication (up to 99 % reduction), photochemical oxidant formation (99 %), and marine eutrophication (98 %). The framework secures a more robust comparison of emerging bio-based products with conventional fossil-based alternatives, and as such it helps the identification of the improvements in both the bio-based technological processes and background supply chains that are needed to make bio-based systems outperform their fossil counterparts. A consistent integration of ex-ante and prospective LCA is instrumental to prioritize research and investments for upscaling the early-stage technologies that are most promising from a sustainability perspective, and ultimately guide a sustainable transition towards a circular bioeconomy.

Natural sunlight-driven oxidation of Mn2+(aq) and heterogeneous formation of Mn oxides on hematite

The oxidation of dissolved Mn2+(aq) plays a critical role in driving manganese cycles and regulating the fate of essential elements and contaminants in environmental systems. Based on sluggish oxidation rate, abiotic processes have been considered less effective oxidation pathway for manganese oxidation in environmental systems. Interestingly, a recent study (Jung et al., 2021) has shown that the rapid photochemical oxidation of Mn2+(aq) could be a feasible scenario to uncover the potential significance of abiotic Mn2+(aq) oxidation. Nevertheless, the significance of photochemical oxidation of Mn2+(aq) under natural sunlight exposure remains unclear. Here, we demonstrate the rapid photocatalytic oxidation of Mn2+(aq) and the heterogeneous growth of tunnel-structured Mn oxides under simulated freshwater and seawater conditions in the presence of natural sunlight and hematite. The natural sunlight-driven photocatalytic oxidation of Mn2+(aq) by hematite showed kinetic constants of 1.02 h−1 and 0.342 h−1 under freshwater and seawater conditions, respectively. The natural sunlight-driven photocatalytic oxidation rates are quite comparable to the results obtained from the previous laboratory test using artificial sunlight, which has ∼4.5 times stronger light intensity. It is likely because of ∼5.5 times larger light exposure area in the natural sunlight-driven photocatalytic oxidation than that of the laboratory test using artificial sunlight. We also elucidate the roles of cation species in controlling the oxidation rate of Mn2+(aq) and the crystalline structure of Mn oxide products. Specifically, in the presence of large amounts of cations, the oxidation rate of Mn2+(aq) was slower likely because of competitive adsorption. Furthermore, our findings highlight that Mg2+ contributes significantly to the formation of large-tunneled Mn oxides. These results illuminate the importance of abiotic photocatalytic processes in controlling the redox chemistry of Mn in real environmental aqueous systems on the oxidation of Mn2+(aq), and provide an environmentally sustainable approach to effectively remediate water contaminated with Mn2+(aq) using natural sunlight.

Environmental impacts evaluation and promotion measures of wood-based composite doors

China is one of the biggest producers of wooden doors all over the world, and the wood-based composite doors are the most popular wooden door type in the country. In the context of energy-efficient and environment-friendly, assessing the environmental impacts of wood-based composite doors has become a necessity. The aim of this study was to comprehensively estimate the cradle-to-grave environmental effects of wood-based composite doors by Life Cycle Assessment (LCA). Using the eFootprint software, LCA study of wood-based composite doors was conducted according to the rules of ISO 14040 and ISO 14044. The selected environmental indicators were: respiratory inorganics (RI), global warming potential (GWP), eutrophication potential (EP), water use (WU), primary energy demand (PED), acidification potential (AP), photochemical oxidation formation potential (POFP), abiotic depletion potential (ADP), and ozone depletion potential (ODP). The results indicated that the production phase of raw and auxiliary material was the largest contributor to the environmental effects in terms of ADP, AP, PED, EP, GWP, RI, WU, ODP, and POFP, with the relative share ranging from 49 % to 99 %. The medium density fiberboard was the largest environmental hotspot because of the use of urea-formaldehyde resin. The end-of-life disposal also had a noticeable influence on environmental impact of the door. While the door manufacturing phase and transport phase had less environmental effects. The improvement measures were put forward from two aspects of door manufacturers and their suppliers. In addition, the feasibility and environmental benefits of door recycling was also discussed. The current results can help wood-based composite door manufacturers understand and improve the environmental performance of products.

Molecular compositions and sources of organic aerosols at a rural site on the Guanzhong Plain, Northwest China: The importance of biomass burning

The concentration of PM2.5 has considerably reduced in recent years, but remains relatively high in China. In particular, the increasing contribution of organic compounds to PM2.5 generates popular pressure for further reductions, resulting in an urgent need to study organic aerosol (OA). To investigate the molecular composition and source contribution of OA in the rural area of the Guanzhong Plain, Northwest China, PM2.5 samples were collected during 3–23 August 2016 and 5–20 January 2017 and studied for more than 100 organic tracer compounds. The mean concentration of total measured organic compounds is 662 ± 296 ng/m3 in summer and 3258 ± 1925 ng/m3 in winter. Levoglucosan is the most abundant single compound found throughout the sampling period, which is a crucial tracer for biomass burning emissions, preliminary suggesting that biomass burning is an essential source of OA. In summer, organic compounds such as lipid compounds, sugar compounds, and polycyclic aromatic hydrocarbons (PAHs), more come from higher plants, wood burning, vehicle exhausts, plastic waste, and other direct emission sources. Oxygenated PAHs (OPAHs), nitrophenols, and phthalic acids more come from the atmosphere through the oxidation reaction of aromatic precursors, especially photochemical oxidation. However, in winter, most of the increases in concentrations of organic compounds are attributed to biomass burning. The analysis of a haze event (14–19 January 2017) during the winter sampling period shows that the increases in the concentration of organic compounds are unaccompanied by strong secondary formation under lower relative humidity (49.1% ± 13.5%). The main reason for the growth of OA in this haze event is the accumulation of primary OA (POA). The source apportionment by the positive matrix factorization (PMF) model shows that biomass burning (37.1%) is the primary source of OA in the rural regions of the Guanzhong Plain, especially in winter (40.6%). The contribution of secondary formation decreases from 26.0% in summer to 16.9% in winter, and the contribution of fossil fuel emissions is comparable across both seasons.

Life Cycle Assessment of Tomato Cultivated in an Innovative Soilless System

The main goal of this study is to present the life cycle assessment results of an innovative closed-loop production system, called an agriponic system, used for producing tomatoes. In the study, this new system is presented, as well as its related environmental impacts generated for the production of the tomatoes. A life cycle assessment (according to ISO 14040) was applied to it, from seedling purchase and planting to harvest, using a functional unit of 1 ton of cherry tomatoes produced. SimaPro 9.3.0.3 software and the Ecoinvent database were used to analyze five impact categories. Plant growth emerged as the process unit with the highest impact, particularly for the ozone depletion potential (ODP), with a value of 0.00056 kgCFC-11eq, and for photochemical oxidation (POCP), with a value of 0.0784 kgC2H4eq impact categories. Greenhouse climate management presented a significant impact to the acidification potential (AP), with a value of 1.021 kgSO2eq. Conversely, the phases of plant transplanting, harvesting, and crop disposal had positive impacts for all impact categories considered in the study, because they were very low. In conclusion, agriponic greenhouse tomato production is a sustainable process. This is due to fewer pesticides that are used, and to nutrient solution reuse.

Online monitoring of carbonaceous aerosols in a northern Chinese city: Temporal variations, main drivers, and health risks

This study examined the variability and source of carbonaceous aerosols, encompassing total carbon (TC), organic carbon (OC), and secondary organic carbon (SOC) for the years 2019–2020, as well as equivalent black carbon (eBC) and equivalent ultraviolet BC (eUVBC) data spanning 2019–2022, in the context of a typical northern Chinese city: Yanzhou. Averaged concentrations of TC, OC, SOC, eBC, eUVBC, and the ratio (OC/elemental carbon (EC)) reached 11.1 ± 6.7, 8.9 ± 5.1, 3.9 ± 2.0, 3.1 ± 1.3, and 4.3 ± 2.4 μg/m3, and 5.0 ± 2.2, respectively. The concentrations of TC, OC, eBC, and eUVBC were higher in winter, followed by spring and autumn, and summer, while SOC presented the opposite seasonal patterns. The diurnal variations of TC, OC, eBC, and eUVBC exhibited a bimodal pattern with peaks in the early morning (08:00–09:00 LT) and late evening (00:00–01:00 LT) and a trough in the afternoon (14:00–16:00 LT), pointing to vehicular emission and meteorological dispersion as major drivers of the hourly variability. The results obtained from the EC tracer method and minimum R squared (MRS) revealed that r(SOC/OC) were highest in summer (60%) and lowest in winter (26%), showing a fast summer photochemical oxidation of volatile organic compounds (VOCs) that generate SOC. In this study, the influence of meteorological conditions on the weighting of diverse carbonaceous aerosols was quantified using a machine learning method. Results showed that the main drivers of carbonaceous aerosols were height of the planetary boundary layer (HPBL), ambient temperature (AT), relative humidity (RH), and atmospheric pressure (AP) in all seasons. Additionally, the potential health risks of eBC based on the equivalent passive smoking of cigarettes (PSC) suggested that there was a certain level of human health risk in this city. The obtained results will provide more in-depth and comprehensive understanding of carbonaceous aerosol pollution and management strategies.

Efficient Analysis of Proteome-Wide FPOP Data by FragPipe.

Monitoring protein structure before and after environmental alterations (e.g., different cell states) can give insights into the role and function of proteins. Fast photochemical oxidation of proteins (FPOP) coupled with mass spectrometry (MS) allows for monitoring of structural rearrangements by exposing proteins to OH radicals that oxidize solvent-accessible residues, indicating protein regions undergoing movement. Some of the benefits of FPOP include high throughput and a lack of scrambling due to label irreversibility. However, the challenges of processing FPOP data have thus far limited its proteome-scale uses. Here, we present a computational workflow for fast and sensitive analysis of FPOP data sets. Our workflow, implemented as part of the FragPipe computational platform, combines the speed of the MSFragger search with a unique hybrid search method to restrict the large search space of FPOP modifications. Together, these features enable more than 10-fold faster FPOP searches that identify 150% more modified peptide spectra than previous methods. We hope this new workflow will increase the accessibility of FPOP to enable more protein structure and function relationships to be explored.

UVA‐Light‐Promoted Catalyst‐Free Photochemical Aerobic Oxidation of Boronic Acids

AbstractThe hydroxy group, and the phenol moiety in particular, is ubiquitous in several natural products, in organic synthesis and/or pharmaceutical industry. With the uprise of photoredox catalysis, many efforts worldwide focus on developing novel and sustainable protocols, providing an easy access to hydroxy‐containing molecules. Boronic acids and boronic ester derivatives are considered valuable precursors for the synthesis of hydroxy group derivatives. Herein, we report a novel, sustainable, light‐driven protocol, where the impact of wavelength irradiation on boronic acid aerobic photooxidation was examined. In this work, UVA‐light (370 nm) irradiation was found to promote the photocatalyst‐free aerobic oxidation of boronic acids and boronic acid derivatives. Furthermore, a broad scope of substrates was tested, and extensive mechanistic studies were performed in order to probe the reaction mechanism.