A comparative study on the formation of nitrogen-containing organic compounds in cloud droplets and aerosol particles.

Nitrogen-containing organic compounds (NOCs) may potentially contribute to aqueous secondary organic aerosols, yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear. With the in-situ measurements performed at a mountain site (1690 m a.s.l.) in southern China, we investigated the formation of NOCs in the cloud droplets and the cloud-free particles, based on their mixing state information of NOCs-containing particles by single particle mass spectrometry. The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual (cloud RES) particles. NOCs were highly correlated with carbonyl compounds (including glyoxalate and methylglyoxal) in the cloud-free particles, however, limited correlation was observed for cloud RES particles. Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles, rather than in the cloud RES particles. The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols, rather than cloud droplets. In addition, we have identified the transport of biomass burning particles that facilitate the formation of NOCs, and that the observed NOCs is most likely contributed to the light absorption. These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.

Chemical characteristics and sources apportionment of volatile organic compounds in the primary urban area of Shijiazhuang, North China Plain.

VOCs (Volatile organic compounds) exert a vital role in ozone and secondary organic aerosol production, necessitating investigations into their concentration, chemical characteristics, and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution. From July to October 2020, online monitoring was conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity. Additionally, the PMF (positive matrix factorization) method was utilized to identify the VOCs sources. Results indicated that the TVOCs (total VOCs) concentration was (96.7 ± 63.4 µg/m3), with alkanes exhibiting the highest concentration of (36.1 ± 26.4 µg/m3), followed by OVOCs (16.4 ± 14.4 µg/m3). The key active components were alkenes and aromatics, among which xylene, propylene, toluene, propionaldehyde, acetaldehyde, ethylene, and styrene played crucial roles as reactive species. The sources derived from PMF analysis encompassed vehicle emissions, solvent and coating sources, combustion sources, industrial emissions sources, as well as plant sources, the contribution of which were 37.80%, 27.93%, 16.57%, 15.24%, and 2.46%, respectively. Hence, reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.

Emission characteristics of biogenic volatile organic compounds in a subtropical pristine forest of southern China.

Emission characteristics of biogenic volatile organic compounds (BVOCs) from dominant tree species in the subtropical pristine forests of China are extremely limited. Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients (600-1690 m a.s.l.) in the Nanling Mountains of southern China. Composition characteristics as well as seasonal and altitudinal variations were analyzed. Standardized emission rates and canopy-scale emission factors were then calculated. Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season. Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees, accounting for over 70% of the total. Schima superba, Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials. The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols from Nature (MEGAN), while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model. Our results can be used to update the current BVOCs emission inventory in MEGAN, thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.

Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa.

Furniture is identified as a vital volatile organic compound (VOC) emission source in the indoor environment. Leather has become the most common raw and auxiliary fabric material for upholstered furniture, particularly with extensive consumption in sofas, due to its abundant resources and efficient functions. Despite being widely traded across the world, little research has been conducted on the VOCs released by leather materials and their health risk assessment in the indoor environment. Accordingly, this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure. Based on the ultra-fast gas phase electronic nose (EN) and GC-FID/Qtof, the substantial emissions of aliphatic aldehyde ketones (Aks), particularly hexanal, appear to be the cause of off-flavor in medium and low grade (MG and LG) sofa leathers. The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents. Given the abundance of VOC sources and the accumulation of health risks in the indoor environment, more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.

Sniffing the wine differences: The role of Starmerella bacillaris biofilm-detached cells.

This study investigated the impact of 10 strains of Starmerella bacillaris, co-inoculated as planktonic or biofilm-detached cells with Saccharomyces cerevisiae, on the volatilome of a red wine. The wines produced with St. bacillaris biofilm-detached cells exhibited a greater concentration of glycerol and a lower quantity of ethanol than the other wines. Furthermore, these wines exhibited elevated levels of higher alcohols, organic acids, esters, terpenes, and norisoprenoids. Based on the odor activity value and relative odor contribution, isoamyl acetate, ethyl octanoate, ethyl isobutanoate, and methyl decanoate were the main aroma components of wines made with planktonic cells. The main compounds characterizing the wines obtained with biofilm-detached cells were: phenethyl alcohol, ß-damascenone, citronellol, ß-ionone, and nerol. The sensory analysis revealed that the wines produced with biofilm-detached cells had higher scores for mouth-feel, spicy, floral, and raspberry notes than the others. The present study provides evidence that St. bacillaris biofilm-detached cells released specific volatile compounds in red wines.

Volatile organic compounds of camel milk and shubat across Kazakhstan's regions, seasons, and breeds.

Despite extensive research in recent years on camel milk composition and health benefits, limited scientific data exists on the volatile organic compound profiles of camel milk and its fermented product, shubat. This study analyzed volatile organic compounds (VOCs) in raw camel milk and shubat from six Kazakh farms across all seasons. We found that camel milk displayed higher concentrations of aldehydes, ketones, and alcohols with the main two compounds in milk being acetone and (2-Aziridinylethyl) amine. Conversely, the majority of volatile organic compounds in shubat samples belonged to esters, but the predominant compounds by concentration were ethanol, dimethylamine, propanoic acid, and octanoic acid. Seasonality emerged as the primary driver of variation in milk, with heptanal being the most discriminative compound. Fermented milk showcased regional diversity likely driven by distinct microbial communities. Findings demonstrate the dynamic nature of camel milk's aromatic properties, which are influenced by multiple factors that contribute to its distinctive sensory characteristics.

NMR-based metabolomics for investigating urinary profiles of metal carpentry workers exposed to welding fumes and volatile organic compounds.

Introduction: Metal carpentry includes a wide range of work activities such as welding and cutting metallic components, use of solvents and paints. Therefore, the employees in these types of activities are mainly exposed to welding fumes and volatile organic solvents. Here, we present an NMR-based metabolomic approach for assessing urinary profiles of workers in the same company that are exposed to two different risk factors. Methods: The study enrolled 40 male subjects exposed to welding fumes, 13 male subjects exposed to volatile organic compounds of a metal carpentry company, and 24 healthy volunteers. All samples were collected, in the middle of the working week at fast. Thirty-five urinary metabolites belonging to different chemical classes such as amino acids, organic acids and amines were identified and quantified. Results were processed by multivariate statistical analysis for identifying significant metabolites for each working group examined, compared to controls. Results: Workers exposed to welding fumes displayed urinary increase in glutamine, tyrosine, taurine, creatine, methylguanidine and pseudouridine associated to oxidative impairment, while workers exposed to volatile organic compounds showed higher urinary levels of branched chain aminoacids. Conclusion: Our work identified specific urinary profile related to each occupational exposure, even if it is below the threshold limit values.

Visual detection of aldehyde gases using a silver-loaded paper-based colorimetric sensor array.

The small molecule aldehydes are volatile organic compounds (VOCs), possessing cytotoxicity and carcinogenicity. Long-term exposure can pose a serious threat to human health. Based on an in-situ reduction colorimetric method to generate silver nanoparticles and induce colorimetric response, we proposed a silver-loaded paper-based colorimetric sensor array for visually detecting and differentiating five relatively common trace small molecule aldehyde gases. The silver ions are immobilized onto a porous filter paper and stabilized by complexing agents of branched polyethyleneimine, ethylenediamine, and 1,6-diaminohexane, respectively. The as-fabricated sensor array expresses remarkable stability and capacity to resist humidity. The qualitative analysis reveals that the sensor array has excellent selectivity for aldehyde gases and displays remarkable anti-interference ability. The quantitative analysis indicates that the sensor array exhibits superior sensitivity for five aldehyde gases, with limits of detection (LODs) of 9.0 ppb for formaldehyde (FA), 3.1 ppm for acetaldehyde (AA), 3.5 ppm for propionaldehyde (PA), 23.8 ppb for glutaric dialdehyde (GD), and 71.5 ppb for hydroxy formaldehyde (HF), respectively. Importantly, these LODs are all comfortably below their respective permissible exposure limits. A unique colorimetric response fingerprint is observed for each analyte. Standard chemometric methods illustrate that the sensor array has excellent clustering capability for these aldehyde gases. Additionally, the sensor array's response is irreversible and possesses outstanding performance for cumulative monitoring. This colorimetric sensor array based on silver ions reduced to silver nanoparticles offers a novel detection method for the continuous, ultrasensitive, and visual detection of trace airborne pollutants.

Microbiome-driven IBS metabotypes influence response to the low FODMAP diet: insights from the faecal volatome.

BACKGROUND: Irritable bowel syndrome (IBS) is a common and debilitating disorder manifesting with abdominal pain and bowel dysfunction. A mainstay of treatment is dietary modification, including restriction of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols). A greater response to a low FODMAP diet has been reported in those with a distinct IBS microbiome termed IBS-P. We investigated whether this is linked to specific changes in the metabolome in IBS-P. METHODS: Solid phase microextraction gas chromatography-mass spectrometry was used to examine the faecal headspace of 56 IBS cases (each paired with a non-IBS household control) at baseline, and after four-weeks of a low FODMAP diet (39 pairs). 50% cases had the IBS-P microbial subtype, while the others had a microbiome that more resembled healthy controls (termed IBS-H). Clinical response to restriction of FODMAPs was measured with the IBS-symptom severity scale, from which a pain sub score was calculated. FINDINGS: Two distinct metabotypes were identified and mapped onto the microbial subtypes. IBS-P was characterised by a fermentative metabolic profile rich in short chain fatty acids (SCFAs). After FODMAP restriction significant reductions in SCFAs were observed in IBS-P. SCFA levels did not change significantly in the IBS-H group. The magnitude of pain and overall symptom improvement were significantly greater in IBS-P compared to IBS-H (p = 0.016 and p = 0.026, respectively). Using just five metabolites, a biomarker model could predict microbial subtype with accuracy (AUROC 0.797, sensitivity 78.6% (95% CI: 0.78-0.94), specificity 71.4% (95% CI: 0.55-0.88). INTERPRETATION: A metabotype high in SCFAs can be manipulated by restricting fermentable carbohydrate, and is associated with an enhanced clinical response to this dietary restriction. This implies that SCFAs harbour pro-nociceptive potential when produced in a specific IBS niche. By ascertaining metabotype, microbial subtype can be predicted with accuracy. This could allow targeted FODMAP restriction in those seemingly primed to respond best. FUNDING: This research was co-funded by Addenbrooke's Charitable Trust, Cambridge University Hospitals and the Wellcome Sanger Institute, and supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014).

Multitrophic and Multilevel Interactions Mediated by Volatile Organic Compounds.

Plants communicate with insects and other organisms through the release of volatile organic compounds (VOCs). Using Boolean operators, we retrieved 1093 articles from the Web of Science and Scopus databases, selecting 406 for detailed analysis, with approximately 50% focusing on herbivore-induced plant volatiles (HIPVs). This review examines the roles of VOCs in direct and indirect plant defense mechanisms and their influence on complex communication networks within ecosystems. Our research reveals significant functions of VOCs in four principal areas: activating insect antennae, attracting adult insects, attracting female insects, and attracting natural enemies. Terpenoids like α-pinene and ß-myrcene significantly alter pest behavior by attracting natural enemies. ß-ocimene and ß-caryophyllene are crucial in regulating aboveground and belowground interactions. We emphasize the potential applications of VOCs in agriculture for developing novel pest control strategies and enhancing crop resilience. Additionally, we identify research gaps and propose new directions, stressing the importance of comparative studies across ecosystems and long-term observational research to better understand VOCs dynamics. In conclusion, we provide insights into the multifunctionality of VOCs in natural ecosystems, their potential for future research and applications, and their role in advancing sustainable agricultural and ecological practices, contributing to a deeper understanding of their mechanisms and ecological functions.

Research on the Design and Performance of Plant Volatile Organic Compounds Water Removal Device Based on Optimized Filler Ratio.

This study focuses on the development and optimization of a water removal device for biogenic volatile organic compounds (BVOCs) from plant emissions. BVOCs play a crucial role in various ecological processes and have potential therapeutic effects on human health. However, it is challenging to accurately detect and analyze BVOCs due to their very low concentrations and interference by water vapor. This study systematically evaluates different filler materials and ratios to alleviate water vapor interference while maintaining BVOCs' integrity. The experimental results demonstrate that the combination of MgSO4 + Na2SO4 mixed filling and CuSO4 layered filling in a 3:3:1 ratio can effectively improve the collection efficiency and detection accuracy of BVOCs. Meanwhile, the effectiveness of the device in improving the detection of volatile compounds in plant samples is also confirmed by the VOC verification experiments on Michelia maudiae and Cinnamomum camphora tree species after mechanical damage. The experimental results show that the device is effective in improving the detection of volatile compounds in plant samples. The findings provide a powerful technical means for exploring the role of BVOCs in environmental monitoring and scientific research.

An Exploratory Study on the Rapid Detection of Volatile Organic Compounds in Gardenia Fruit Using the Heracles NEO Ultra-Fast Gas Phase Electronic Nose.

Gardenia fruit is a popular functional food and raw material for natural pigments. It comes from a wide range of sources, and different products sharing the same name are very common. Volatile organic compounds (VOCs) are important factors that affect the flavor and quality of gardenia fruit. This study used the Heracles NEO ultra-fast gas phase electronic nose with advanced odor analysis performance and high sensitivity to analyze six batches of gardenia fruit from different sources. This study analyzed the VOCs to find a way to quickly identify gardenia fruit. The results show that this method can accurately distinguish the odor characteristics of various gardenia fruit samples. The VOCs in gardenia fruit are mainly organic acid esters, ketones, and aldehyde compounds. By combining principal component analysis (PCA) and discriminant factor analysis (DFA), this study found that the hexanal content varied the most in different gardenia fruit samples. The VOCs allowed for the fruit samples to be grouped into two main categories. One fruit sample was quite different from the fruits of other origins. The results provide theoretical support for feasibility of rapid identification and quality control of gardenia fruit and related products in the future.

Honeybee (Apis mellifera L.) pollination enhances the yield and flavor quality of kiwifruit.

Pollination is essential for achieving high yields and enhancing the quality of kiwifruit cultivation, both of which significantly influence growers' interests and consumers' preferences. However, compared to studies on yield, there are fewer studies exploring the impact of pollination methods on the flavor of kiwifruit Actinidia chinensis Planchon. This study examined the effects of bee (Apis mellifera L.) pollination and artificial pollination on the yield and flavor of kiwifruit in the main producing areas of China. Compared with those pollinated artificially, bee-pollinated kiwifruit exhibited a greater fruit set rate, heavier fruit weight, and greater number of seeds. Notably, the number of seeds was positively correlated with fruit weight in bee-pollinated kiwifruit, whereas no such correlation was detected in artificially pollinated fruit. Bee pollination not only enhanced the yield but also improved the flavor of kiwifruit. Specifically, bee-pollinated kiwifruit contained higher levels of sucrose and lower concentrations of glucose and fructose, while the acid content was less affected by pollination methods. Furthermore, significant differences were observed in the volatile organic compound (VOC) levels in kiwifruit subjected to different pollination treatments, with bee-pollinated fruit exhibiting a superior flavor. Our findings provide new insights into the beneficial role of bee pollination in enhancing kiwifruit yield and quality, underscoring the crucial importance of bees in kiwifruit pollination.

Breathomics for diagnosing tuberculosis in diabetes mellitus patients.

Introduction: Individuals with diabetes mellitus (DM) are at an increased risk of Mycobacterium tuberculosis (Mtb) infection and progressing from latent tuberculosis (TB) infection to active tuberculosis disease. TB in the DM population is more likely to go undiagnosed due to smear-negative results. Methods: Exhaled breath samples were collected and analyzed using high-pressure photon ionization time-of-flight mass spectrometry. An eXtreme Gradient Boosting (XGBoost) model was utilized for breathomics analysis and TB detection. Results: XGBoost model achieved a sensitivity of 88.5%, specificity of 100%, accuracy of 90.2%, and an area under the curve (AUC) of 98.8%. The most significant feature across the entire set was m106, which demonstrated a sensitivity of 93%, specificity of 100%, and an AUC of 99.7%. Discussion: The breathomics-based TB detection method utilizing m106 exhibited high sensitivity and specificity potentially beneficial for clinical TB screening and diagnosis in individuals with diabetes.

Exploring modes of microbial interactions with implications for methane cycling.

Methanotrophs are the sole biological sink of methane. Volatile organic compounds (VOCs) produced by heterotrophic bacteria have been demonstrated to be a potential modulating factor of methane consumption. Here, we identify and disentangle the impact of the volatolome of heterotrophic bacteria on the methanotroph activity and proteome, using Methylomonas as model organism. Our study unambiguously shows how methanotrophy can be influenced by other organisms without direct physical contact. This influence is mediated by VOCs (e.g. dimethyl-polysulphides) or/and CO2 emitted during respiration, which can inhibit growth and methane uptake of the methanotroph, while other VOCs had a stimulating effect on methanotroph activity. Depending on whether the methanotroph was exposed to the volatolome of the heterotroph or to CO2, proteomics revealed differential protein expression patterns with the soluble methane monooxygenase being the most affected enzyme. The interaction between methanotrophs and heterotrophs can have strong positive or negative effects on methane consumption, depending on the species interacting with the methanotroph. We identified potential VOCs involved in the inhibition while positive effects may be triggered by CO2 released by heterotrophic respiration. Our experimental proof of methanotroph-heterotroph interactions clearly calls for detailed research into strategies on how to mitigate methane emissions.

Identification potential biomarkers for diagnosis, and progress of breast cancer by using high-pressure photon ionization time-of-flight mass spectrometry.

BACKGROUND: In this study, exhaled breath testing has been considered a promising method for the detection and monitoring of breast cancer (BC). METHODS: A high-pressure photon ionization time-of-flight mass spectrometry (HPPI-TOFMS) platform was used to detect volatile organic compounds (VOCs) in breath samples. Then, machine learning (ML) models were constructed on VOCs for the diagnosis of BC and its progression monitoring. Ultimately, 1981 women with useable breath samples were included in the study, of whom 937 (47.3 %) had been diagnosed with BC. VOC panels were used for ML model construction for BC detection and progression monitoring. RESULTS: On the blinded testing cohort, this VOC-based model successfully differentiated patients with and without BC with sensitivity, specificity, and area under receiver operator characteristic curve (AUC) values of 85.9 %, 90.4 %, and 0.946. The corresponding AUC values when differentiating between patients with and without lymph node metastasis (LNM) or between patients with tumor-node-metastasis (TNM) stage 0/I/II or III/IV disease were 0.840 and 0.708, respectively. While developed VOC-based models exhibited poor performance when attempting to differentiate between patients based on pathological patterns (Ductal carcinoma in situ (DCIS) vs Invasive BC (IBC)) or molecular subtypes (Luminal vs Human epidermal growth factor receptor 2 (HER2+) vs Triple-negative BC (TNBC)) of BC. CONCLUSION: Collectively, the HPPI-TOFMS-based breathomics approaches may offer value for the detection and progression monitoring of BC. Additional research is necessary to explore the fundamental mechanisms of the identified VOCs.

Exposure to volatile organic compounds and growth indicators in adolescents: Unveiling the association and potential intervention strategies.

Environmental pollutant is considered to be one of the important factors affecting adolescent growth. However, the effects of volatile organic compounds (VOCs) exposure on adolescent growth have not been assessed. Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 was used to examine the associations between VOCs exposure and adolescent growth indicators through three statistical models. The mediating effect of bone mineral density (BMD) on these associations was examined. The potential pathways and key targets were identified by the network pharmacology analysis methods. This study included 746 adolescents. Three statistical methods consistently showed a negative correlation between VOCs exposure and adolescent growth indicators. Furthermore, BMD mediated the relationship between VOCs exposure and adolescent growth indicators, with mediated proportion ranging from 4.3 % to 53.4 %. Network pharmacology analysis found a significant enrichment in IL-17 signaling pathway. Moreover, the adverse effects of VOCs exposure on adolescent growth were observed to significantly attenuate in adolescents with high serum vitamin D levels. Our results suggested that VOCs exposure was an adverse factor affecting adolescent growth, with BMD playing a significant regulatory role, and IL-17 signaling pathway was the underlying mechanism. Vitamin D supplementation may be a viable strategy to prevent VOCs exposure from affecting adolescent growth.

Carbon based nanocomposites, surface functionalization as a promising material for VOCs (volatile organic compounds) treatment.

Urban residential and industrial growth development affects sustainable and healthful indoor environments. Environmental issues are a global problem. The deterioration of indoor air quality has prompted the creation of several air cleansing techniques. This review explains how carbon-based materials have influenced the development of air purification systems using photocatalysis. These carbon-based materials offer unique properties and advantages in VOC removal processes. Biochar, produced from biomass pyrolysis, provides an environmentally sustainable solution with its porous structure and carbon-rich composition. Carbon quantum dots, with their quantum confinement effects and tunable surface properties, show promise in VOC sensing and removal applications. Polymers incorporating reduced graphene oxide demonstrate enhanced adsorption capabilities owing to the synergistic effects of graphene and polymer matrices. Activated carbon fibers, characterized by their high aspect ratio and interconnected porosity, provide efficient VOC removal with rapid kinetics. With their unique electronic and structural properties, graphitic carbon nitrides offer opportunities for photocatalytic degradation of VOCs under visible light. Catalysts integrated with MXene, a two-dimensional nanomaterial, exhibit enhanced catalytic activity for VOC oxidation reactions. Using various carbon-based materials in VOC removal showcases the versatility and effectiveness of carbon-based approaches in addressing environmental challenges associated with indoor air pollution. Metal-organic-framework materials are carbon-based compounds. It examines the correlation between VOC mineralization and specific characteristics of carbon materials, including surface area, adsorption capability, surface functional groups, and optoelectronic properties. Discussions include the basics of PCO, variables influencing how well catalysts degrade, and degradation mechanisms. It explores how technology will improve in the future to advance studies on healthy and sustainable indoor air quality.

Highly efficient Cu(II) coordination polymer catalyst for the conversion of hazardous volatile organic compounds.

Three novel coordination polymers (CPs), namely [Cu(µ-1κO,2κN-L)2]n (1), [Zn (µ-1κO,2κN-L)2(H2O)2]n (2) and [Cd (µ-1κOO',2κN-L)2]n (3) [where HL = 4-(pyrimidin-5-ylcarbamoyl)benzoic acid], were synthesized and characterized by elemental analysis, ATR-IR, TGA, XPS and single-crystal X-ray diffraction. Despite having the same organic ligand, the various metal cations had an impact in the subsequent frameworks. Hirshfeld surface analysis was performed to investigate the intermolecular interactions and to examine the stability of the crystal structures of the three polymers. Their catalytic performances were screened for the peroxidative oxidation of Volatile Organic Compounds (VOCs), with toluene and p-xylene selected as model substrates. Tert-butyl hydroperoxide (t-BuOOH or TBHP) (aq. 70 %) was employed as the oxidant. The catalytic oxidation of toluene yielded benzyl alcohol, benzaldehyde and benzoic acid. The copper CP 1 exhibited the highest total yield for toluene oxidation, reaching approximately 36% in an aqueous medium. For p-xylene oxidation, tolualdehyde, methylbenzyl alcohol, and toluic acid were produced as the primary products, accompanied by minor ones. The experiments were conducted under diverse conditions, manipulating key parameters such as the choice of solvent (water or acetonitrile), type of oxidant (t-BuOOH or H2O2), the concentration of the oxidant and reaction temperature. In the presence of catalyst 1, a maximum total yield of ca. 80% was achieved for p-xylene oxidation.

Benzotriazoles and bisphenols in wastewater from the food processing industry and the quantitative changes during mechanical/biochemical treatment processes.

Benzotriazoles (BTRs) and bisphenols (BPs), categorized as contaminants of emerging concern (CECs), pose significant risks to human health and ecosystems due to their endocrine-disrupting properties and environmental persistence. This study investigates the occurrence and behavior of nine BTRs and ten BPs in wastewater generated in a large-scale meat processing plant, evaluating the effectiveness of a modern mechanical-biological industrial on-site treatment plant in removing these contaminants, and based on the concentration levels from eleven sampling points at different stages of the treatment process. The method used to determine these micropollutants' concentration was ultrasound-assisted emulsification-microextraction for analytes isolation and gas chromatography-mass spectrometry for detection (USAEME-GC/MS). The results indicate that the rigorous quality control processes in the meat processing facility effectively limit the presence of these micropollutants, especially concerning BPs, which are absent or below detection limits in raw wastewater. While the concentrations of some of these micropollutants increased at different points in the treatment process, these values were relatively low, typically below one microgram per liter. Among the compounds analyzed, the only one present after completing the treatment was 5Cl-BTR (maximum concentration: 3007 ng/L), and these contamination levels are around seven times lower than the reference value associated with non-cancer health risk for drinking water. This study contributes to understanding these CECs in industrial wastewater and highlights the importance of effective treatment systems for environmental protection.