Photochemical Degradation of the New Nicotine Pesticide Acetamiprid in Water.

Acetamiprid is a novel nicotinic pesticide widely used in modern agriculture because of its low toxicity and specific biological target properties. The objective of this study was to understand the photolysis pattern of acetamiprid in the water column and elucidate its degradation products and mechanism. It was observed that acetamiprid exhibited different photolysis rates under different light source conditions in pure water, with ultraviolet > fluorescence > sunlight; furthermore, its photolysis half-life ranged from 17.3 to 28.6 h. In addition, alkaline conditions (pH 9.0) accelerated its photolysis rate, which increased with pH. Using gas chromatography-mass spectrometry, five direct photolysis products generated during the exposure of acetamiprid to pure water were successfully separated and identified. The molecular structure of acetamiprid was further analyzed using density functional theory, and the active photodegradation sites of acetamiprid were predicted. The mechanism of the photolytic transformation of acetamiprid in water was mainly related to hydroxyl substitution and oxidation. Based on these findings, a comprehensive transformation pathway for acetamiprid was proposed.

Broken but not beaten: Challenge of reducing the amyloids pathogenicity by degradation.

BACKGROUND: The accumulation of ordered protein aggregates, amyloid fibrils, accompanies various neurodegenerative diseases (such as Parkinson's, Huntington's, Alzheimer's, etc.) and causes a wide range of systemic and local amyloidoses (such as insulin, hemodialysis amyloidosis, etc.). Such pathologies are usually diagnosed when the disease is already irreversible and a large amount of amyloid plaques have accumulated. In recent years, new drugs aimed at reducing amyloid levels have been actively developed. However, although clinical trials have demonstrated a reduction in amyloid plaque size with these drugs, their effect on disease progression has been controversial and associated with significant side effects, the reasons of which are not fully understood. AIM OF REVIEW: The purpose of this review is to summarize extensive array of data on the effect of exogenous and endogenous factors (physico-mechanical effects, chemical effects of low molecular weight compounds, macromolecules and their complexes) on the structure and pathogenicity of mature amyloids for proposing future directions of the development of effective and safe anti-amyloid therapeutics. KEY SCIENTIFIC CONCEPTS OF REVIEW: Our analysis show that destruction of amyloids is in most cases incomplete and degradation products often retain the properties of amyloids (including high and sometimes higher than fibrils, cytotoxicity), accelerate amyloidogenesis and promote the propagation of amyloids between cells. Probably, the appearance of protein aggregates, polymorphic in structure and properties (such as amorphous aggregates, fibril fragments, amyloid oligomers, etc.), formed because of uncontrolled degradation of amyloids, may be one of the reasons for the ambiguous effectiveness and serious side effects of the anti-amyloid drugs. This means that all medications that are supposed to be used both for degradation and slow down the fibrillogenesis must first be tested on mature fibrils: the mechanism of drug action and cytotoxic, seeding, and infectious activity of the degradation products must be analyzed.

Degradation of veterinary antibiotics by the ozonation process: Product identification and ecotoxicity assessment.

The purpose of the study was to evaluate the effects of using of ozonation to remove antibiotics used, among others, in veterinary medicine, from the aqueous environment. The effect of this process on the degradation, mineralisation and ecotoxicity of aqueous solutions of ampicillin, doxycycline, tylosin, and sulfathiazole was investigated. Microbiological MARA® bioassay and two in silico methods were used for the ecotoxicity assessment. Ozonation was an effective method for the degradation of the antibiotics studied and the reduction in ecotoxicity of the solutions. However, after ozonation, the solutions contained large amounts of organic products, including compounds much less susceptible to ozonation than the initial antibiotics. Structures of 14, 12, 40 and 10 degradation products for ampicillin, doxycycline, tylosin, and sulfathiazole, respectively, were proposed. It was confirmed that ozone plays a greater role than hydroxyl radicals in the degradation of these antibiotics, with the exception of TYL. The use of ozonation to obtain a high degree of mineralisation is unfavourable and it is suggested to combine ozonation with biodegradation. The pre-ozonation will cause decomposition of antibiotic pharmacophores, which significantly reduces the risk of spread of antimicrobial resistance in the active biocenosis of wastewater treatment plants.

Identification and Mechanistic Analysis of Toxic Degradation Products in the Advanced Oxidation Pathways of Fluoroquinolone Antibiotics.

The degradation of fluoroquinolones (FQs) via advanced oxidation processes (AOPs) is a promising avenue, yet the complete mineralization of certain FQ molecules remains elusive, raising concerns about the formation of toxic by-products. This study delineates five primary AOP degradation pathways for 16 commercially available FQ molecules, inferred from existing literature. Density functional theory (DFT) was employed to calculate the bond dissociation energies within these pathways to elucidate the correlation between bond strength and molecular architecture. Subsequently, Comparative Molecular Similarity Index Analysis (CoMSIA) models were constructed for various degradation reactions, including piperazine ring cleavage, defluorination, hydroxylation, and piperazine ring hydroxylation. Three-dimensional contour maps generated from these models provide a deeper understanding of the interplay between FQ molecular structure and bond dissociation energy. Furthermore, toxicity predictions for 16 FQ molecules and their advanced oxidation intermediates, conducted using VEGA 1.2.3 software, indicate that degradation products from pathways P2 and P5 pose a heightened health risk relative to their parent compounds. Furthermore, the application of the Multwfn program to compute the Fukui function for FQ molecules discerns the disparity in degradation propensities, highlighting that N atoms with higher f0 values can augment the likelihood of piperazine ring cleavage. HOMO-LUMO distribution diagrams further confirm that methoxy substitution at the 1-position leads to a dilution of HOMOs on the piperazine ring and an increased energy gap for free radical reactions, diminishing the reactivity with hydroxyl radicals. This study elucidates the pivotal role of structural characteristics in FQ antibiotics for their degradation efficiency within AOPs and unveils the underlying mechanisms of bond dissociation energy disparities. The toxicity parameter predictions for FQ molecules and their intermediates offer unique perspectives and theoretical underpinnings for mitigating the use of high-risk FQs and for devising targeted degradation strategies to circumvent the generation of toxic intermediates in AOPs through molecular structure optimization.

Degradation Mechanism of Aflatoxin M1 by Recombinant Catalase from Bacillus pumilusE-1-1-1: Food Applications in Milk and Beer.

A bacteria capable of degrading aflatoxin M1 (AFM1) was isolated from African elephant manure. It was identified as Bacillus pumilus by 16s rDNA sequencing and named B. pumilusE-1-1-1. Compared with physical and chemical methods, biological methods have attracted much attention due to their advantages, such as thorough detoxification, high specificity, and environmental friendliness. This work aimed to study the effects of a recombinant catalase (rCAT) from B. pumilusE-1-1-1 on the degradation of AFM1 in pattern solution. The degradation mechanism was further explored and applied to milk and beer. Kinetic Momentum and Virtual Machine Maximum values for rCAT toward AFM1 were 4.1 µg/mL and 2.5 µg/mL/min, respectively. The rCAT-mediated AFM1 degradation product was identified as C15H14O3. Molecular docking simulations suggested that hydrogen and pi bonds played major roles in the steadiness of AFM1-rCAT. In other work, compared with identical density of AFM1, survival rates of Hep-G2 cells incubated with catalase-produced AFM1 degradation products increased by about 3 times. In addition, degradation rates in lager beer and milk were 31.3% and 47.2%, respectively. Therefore, CAT may be a prospective substitute to decrease AFM1 contamination in pattern solution, milk, and beer, thereby minimizing its influence on human health.

Evaluation of preoperative coagulation function changes and deep vein thrombosis incidence in elderly patients with hip fractures.

OBJECTIVE: This study involved an analysis of preoperative deep vein thrombosis (DVT) incidence and changes in coagulation function among elderly patients suffering from hip fractures. The objective was to offer guidance on the prevention and management of preoperative DVT in the lower extremities of elderly individuals with hip fractures. METHODS: A total of 282 elderly individuals with a hip fracture were enrolled and divided into two groups based on the location of the fracture: femoral intertrochanteric fracture (FIF, 161 individuals) and femoral neck fracture (FNF, 121 individuals). The two groups were compared with respect to baseline characteristics, including gender, age, and comorbid chronic diseases. Furthermore, the analysis encompassed the incidence of preoperative DVT in both lower extremities, along with seven coagulation parameters and platelet count before the surgical procedure. RESULTS: There was no significant difference in baseline information between the two groups. The incidence of preoperative DVT in the FIF group was higher than that in the FNF group, along with a significantly higher percentage of patients exhibiting increased levels of D-dimer and fibrinogen/fibrin degradation products (FDPs). CONCLUSION: Preoperative hypercoagulability and a greater prevalence of DVT were observed in elderly individuals with FIF compared to individuals with FNF. This indicates that clinicians should pay attention to elderly patients with FIFs, especially those with increased D-dimer and FDP levels.

Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process: Experimental and theoretical study.

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone (NMT) and its major metabolite 6-methoxy-2-naphthylacetic acid (MNA) in the coupling process of ultraviolet and monochloramine (UV/NH2Cl). The second-order rate constants of the contaminants reacting with reactive radicals (HO•, Cl•, Cl2•⁻, and CO3•⁻) were determined by laser flash photolysis experiments. HO• and Cl• contributed predominantly with 52.3% and 21.7% for NMT degradation and 60.8% and 22.3% for MNA degradation. The presence of chlorides retarded the degradation of NMT, while promoted the destruction of MNA, which was ascribed to the photosensitization effects of MNA under UV irradiation. Density functional theory (DFT) calculations revealed that radical adduct formation (RAF) was dominant pathway for both HO• and Cl• reacting with the contaminants, and hydrogen atom transfer (HAT) preferred to occur on side chains of NMT and MNA. NMT reacted with NO2• through single electron transfer (SET) with the second-order rate constant calculated to be 5.35 × 107 (mol/L)-1 sec-1, and the contribution of NO2• was predicted to be 13.0% of the total rate constant of NMT in pure water, which indicated that NO2• played a non-negligible role in the degradation of NMT. The acute toxicity and developmental toxicity of NMT were enhanced after UV/NH2Cl treatment, while those of MNA were alleviated. The transformation products of both NMT and MNA exhibited higher mutagenicity than their parent compounds. This study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

The acute toxicity of Novichok's degradation products using quantitative and qualitative toxicology in silico methods.

The emergence of Novichok agents, potent organophosphorus nerve agents, has spurred the demand for advanced analytical methods and toxicity assessments as a result of their involvement in high-profile incidents. This study focuses on the degradation products of Novichok agents, particularly their potential toxic effects on biological systems. Traditional in vivo methods for toxicity evaluation face ethical and practical constraints, prompting a shift toward in silico toxicology research. In this context, we conducted a comprehensive qualitative and quantitative analysis of acute oral toxicity (AOT) for Novichok degradation products, using various in silico methods, including TEST, CATMoS, ProTox-II, ADMETlab, ACD/Labs Percepta, and QSAR Toolbox. Adopting these methodologies aligns with the 3Rs principle, emphasising Replacement, Reduction, and Refinement in the realm of toxicological studies. Qualitative assessments with STopTox and admetSAR revealed toxic profiles for all degradation products, with predicted toxicophores highlighting structural features responsible for toxicity. Quantitative predictions yielded varied estimates of acute oral toxicity, with the most toxic degradation products being EOPAA, MOPGA, MOPAA, MPGA, EOPGA, and MPAA, respectively. Structural modifications common to all examined hydrolytic degradation products involve substituting the fluorine atom with a hydroxyl group, imparting consequential effects on toxicity. The need for sophisticated analytical techniques for identifying and quantifying Novichok degradation products is underscored due to their inherent reactivity. This study represents a crucial step in unravelling the complexities of Novichok toxicity, highlighting the ongoing need for research into its degradation processes to refine analytical methodologies and fortify readiness against potential threats.

Temperature-responsive comprehensive two-dimensional liquid chromatography coupled to high resolution mass spectrometry for the elucidation of the oxidative degradation processes of chemicals of environmental concern.

This study explores the possibilities offered by temperature-responsive liquid chromatography (TRLC) based comprehensive 2-dimensional liquid chromatography in combination with reversed-phase liquid chromatography (RPLC) for the analysis of degradation products formed upon oxidative treatment of persistent organic pollutants, in this case exemplified through carbamazepine (CBZ). The TRLC×RPLC combination offers the possibility to overcome peak overlap and incomplete separation encountered in 1D approaches, while the transfer of the purely aqueous mobile phase leads to refocusing of all analytes on the second dimension column. Consequently, this allows for about method-development free and hence, easier LC×LC. The study focuses on the oxidative degradation of CBZ, a compound of environmental concern due to its persistence in water bodies. The TRLC×RPLC combination effectively separates and identifies CBZ and its degradation products, while offering improved selectivity over the individual TRLC or RPLC separations. This allows gathering more understanding of the degradation cascade and allows real-time monitoring of the appearance and disappearance of various degradation products. The compatibility with high-resolution mass spectrometry is last shown, enabling identification of 21 CBZ-related products, nine of which were not previously reported in CBZ degradation studies. The approach's simplicity, optimization-free aspects, and ease of use make it a promising tool for the analysis of degradation pathways in environmental contaminants.

Effect of tannic acid binding on the thermal degradation behavior and product toxicity of boscalid.

The effect of tannic acid (TA) binding on the thermal degradation of boscalid was studied in this work. The results revealed that TA binding has a significant impact on boscalid degradation. The degradation rate constant of bound boscalid was reduced, and its corresponding half-life was significantly prolonged compared to the free state. Four identical degradation products were detected in both states through UHPLC-Q-TOF-MS, indicating that degradation products were not affected by TA binding. Based on DFT and MS analysis, the degradation pathways of boscalid included hydroxyl substitution of chlorine atoms and cleavage of CN and CC bonds. The toxicity of B2 and B3 exceeded that of boscalid. In summary, the binding of TA and boscalid significantly affected the thermal degradation rate of boscalid while preserving the types of degradation products. This study contributed to a fundamental understanding of the degradation process of bound pesticide residues in complex food matrices.

Towards a better understanding of light-glucose induced modifications on the structure and biological activity of formulated Nivolumab.

In the last years, monoclonal antibodies (mAbs) have rapidly escalated as biopharmaceuticals into cancer treatments, mainly for their target specificity accompanied by less side effects than the traditional chemotherapy, and stimulation of reliable long-term anti-tumoral responses. They are potentially unstable macromolecules under shaking, temperature fluctuations, humidity, and indoor and outdoor light exposure, all stressors occurring throughout their production, transport, storage, handling, and administration steps. The chemical and physical modifications of mAbs can lead not only to the loss of their bioactivity, but also to the enhancement of their immunogenicity with increasing risk of severe hypersensitivity reactions in treated patients because of aggregation. The photostability of Nivolumab, the active principle of Opdivo®, has been here studied. The chemical modifications detected by LC-MS/MS after the light stressor showed Trp and Met mono and double oxidations as primary damage induced by light on this mAb. The oxidations were stronger when the mAb was diluted in sterile glucose solution where 5-HMF, a major heat glucose degradation product, acted as singlet oxygen producer under irradiation. However, no significant changes in the mAb conformation were found. On the contrary, formation of a significant extent of aggregates has been detected after shining high simulated sunlight doses. This again took place particularly when Nivolumab was diluted in sterile glucose, thus raising a direct correlation between the aggregation and the oxidative processes. Finally, the biological activity under light stress assessed by a blockade assay test demonstrated the maintenance of the PD-1 target recognition even under high light doses and in glucose solution, in line with the preservation of the secondary and tertiary structures of the mAb. Based on our results, as sterile glucose is mostly used for children's therapies, special warnings, and precautions for healthcare professionals should be included for their use to the pediatric population.

Degradation products and transformation pathways of sulfamethoxazole chlorination disinfection by-products in constructed wetlands.

Antibiotics and available chlorine coexist in multiple aquatic environments, and thus antibiotics and their chlorinated disinfection by-products (Cl-DBPs) have been a great concern for the nature and human health. Herein, the degradation intermediates and transformation pathways of sulfamethoxazole (SMX) Cl-DBPs in constructed wetlands (CWs) were investigated. A total of five SMX Cl-DBPs and their twenty degradation products in CWs was identified in this study. SMX and its Cl-DBPs influenced the biodegradation rather than the adsorption process in CWs. S1 atom on sulfonyl group of SMX had the strongest nucleophilicity, and was most vulnerable for nucleophilic attack. N5 and N7 on amino groups, and C17 on the methyl group had great electronegativity, and were susceptible to electrophilic reactions. S1-N5 and S1-C8 bonds of SMX are the most prone to cleavage, followed by C11-N5, C16-C17, and C12-N7. The chlorination of SMX mainly occurred at S1, N5, and N7 sites, and went through S-C cleavage, S-N hydrolysis, and desulfonation. The biodegradation of SMX Cl-DBPs in CWs mainly occurred at S1, N5, N7, C8, and C17 sites, and went through processes including oxidation of methyl, hydroxyl and amino groups, desulfonation, decarboxylation, azo bond cleavage, benzene ring cleavage, ß-oxidation of fatty acids under the action of coenzymes. Over half of the SMX Cl-DBPs had greater bioaccumulation potential than their parent SMX, but the environmental risk of SMX Cl-DBPs was effectively reduced through the degradation by CWs.

Exploration of the Dynamic Variations of the Characteristic Constituents and the Degradation Products of Catalpol during the Process of Radix Rehmanniae.

Radix Rehmanniae (RR), a famous traditional Chinese medicine (TCM) widely employed in nourishing Yin and invigorating the kidney, has three common processing forms in clinical practice, including fresh Radix Rehmanniae (FRR), raw Radix Rehmanniae (RRR), and processed Radix Rehmanniae (PRR). However, until now, there has been less exploration of the dynamic variations in the characteristic constituents and degradation products of catalpol as a representative iridoid glycoside with the highest content in RR during the process from FRR to PRR. In this study, an ultra-performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method was successfully established for the simultaneous determination of ten characteristic components to explore their dynamic variations in different processed products of RR. Among them, iridoid glycosides, especially catalpol, exhibited a sharp decrease from RRR to PRR. Then, three degradation products of catalpol were detected under simulated processing conditions (100 °C, pH 4.8 acetate buffer solution), which were isolated and identified as jiofuraldehyde, cataldehyde, and norviburtinal, respectively. Cataldehyde was first reported as a new compound. Moreover, the specificity of norviburtinal in self-made PRR samples was discovered and validated, which was further confirmed by testing in commercially available PRR samples. In conclusion, our study revealed the decrease in iridoid glycosides and the production of new degradation substances during the process from FRR to PRR, which is critical for unveiling the processing mechanism of RR.

Biodegradation of penicillin G sodium by Sphingobacterium sp. SQW1: Performance, degradation mechanism, and key enzymes.

Biodegradation is an efficient and cost-effective approach to remove residual penicillin G sodium (PGNa) from the environment. In this study, the effective PGNa-degrading strain SQW1 (Sphingobacterium sp.) was screened from contaminated soil using enrichment technique. The effects of critical operational parameters on PGNa degradation by strain SQW1 were systematically investigated, and these parameters were optimized by response surface methodology to maximize PGNa degradation. Comparative experiments found the extracellular enzyme to completely degrade PGNa within 60 min. Combined with whole genome sequencing of strain SQW1 and LC-MS analysis of degradation products, penicillin acylase and ß-lactamase were identified as critical enzymes for PGNa biodegradation. Moreover, three degradation pathways were postulated, including ß-lactam hydrolysis, penicillin acylase hydrolysis, decarboxylation, desulfurization, demethylation, oxidative dehydrogenation, hydroxyl reduction, and demethylation reactions. The toxicity of PGNa biodegradation intermediates was assessed using paper diffusion method, ECOSAR, and TEST software, which showed that the biodegradation products had low toxicity. This study is the first to describe PGNa-degrading bacteria and detailed degradation mechanisms, which will provide new insights into the PGNa biodegradation.

Organophosphate triesters and their diester degradation products in the atmosphere-A critical review.

Organophosphate triesters (tri-OPEs) have found substantial use as plasticizers and flame retardants in commercial and industrial products. Despite upcoming potential restrictions on use of OPEs, widespread environmental contamination is likely for the foreseeable future. Organophosphate diesters (di-OPEs) are known biotic or abiotic degradation products of tri-OPEs. In addition, direct use of di-OPEs as commercial products also contributes to their presence in the atmosphere. We review the available data on contamination with tri-OPEs and di-OPEs in both indoor and outdoor air. Concentrations of tri-OPEs in indoor air exceed those in outdoor air. The widespread discovery of tri-OPE traces in polar regions and oceans is noteworthy and is evidence that they undergo long-range transport. There are only two studies on di-OPEs in outdoor air and no studies on di-OPEs in indoor air until now. Current research on di-OPEs in indoor and outdoor air is urgently needed, especially in countries with potentially high exposure to di-OPEs such as the UK and the US. Di-OPE concentrations are higher at e-waste dismantling areas than at surrounding area. We also summarise the methods employed for sampling and analysis of OPEs in the atmosphere and assess the relative contribution to atmospheric concentrations of di-OPEs made by environmental degradation of triesters, compared to the presence of diesters as by-products in commercial triester products. Finally, we identify shortcomings of current research and provide suggestions for future research.

Antimicrobials in Eisenia fetida earthworms: A comprehensive study from method development to the assessment of uptake and degradation.

In this work, an accurate analytical method was developed for the simultaneous analysis of twenty-seven antimicrobials (AMs) in earthworms using liquid chromatography coupled to a triple quadrupole mass spectrometry detector (UHPLC-MS/MS). Adequate apparent recoveries (80-120 %) and limits of quantification (LOQ) (1 µg·kg-1 - 10 µg·kg-1) were obtained, with the exception of norfloxacin (34 µg·kg-1). The method was applied to evaluate the accumulation of sulfamethazine (SMZ) and tetracycline (TC) in earthworms after performing OECD-207 toxicity test, in which Eisenia fetida (E. fetida) organisms were exposed to soils spiked with 10 mg·kg-1, 100 mg·kg-1 or 1000 mg·kg-1 of SMZ and TC, individually. The results confirmed the bioaccumulation of both AMs in the organisms, showing a greater tendency to accumulate SMZ since higher bioconcentration factor values were obtained for this compound at the exposure concentrations tested. In addition, the degradation of both AMs in both matrices, soils and earthworms was studied using liquid chromatography coupled to a q-Orbitrap high resolution mass spectrometry detector. Thirteen transformation products (TPs) were successfully identified, eight of them being identified for the first time in soil/earthworm (such as 4-Amino-3-chloro-n-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide or 4-(dimethylamino)-1,11,12a-trihydroxy-6,6-dimethyl-3,7,10,12-tetraoxo-3,4,4a,5,5a,6,7,10,12,12a-decahydrotetracene-2-carboxamide, among others) and their formation/degradation trend over time was also studied. Regarding the biological effects, only SMZ caused changes in earthworm growth, evidenced by weight loss in earthworms exposed to concentrations of 100 mg·kg-1 and 1000 mg·kg-1. Riboflavin decreased at all concentrations of SMZ, as well as at the highest concentration of TC. This indicates that these antibiotics can potentially alter the immune system of E. fetida. This research represents a significant advance in improving our knowledge about the contamination of soil by AM over time. It investigates the various ways in which earthworms are exposed to AMs, either by skin contact or ingestion. Furthermore, it explores how these substances accumulate in earthworms, the processes by which earthworms break them down or metabolise them, as well as the resulting TPs. Finally, it examines the potential effects of these substances on the environment.

Stability study and development of the validated infrared spectrometric method for quantitative analysis of sevoflurane compared with the gas chromatographic method.

Sevoflurane, also called fluoromethyl ether, is an inhalation anesthetic agent used to initiate and maintain general anesthesia for adults and pediatric patients during surgical procedures. Several analytical methods have previously been applied to follow the properties and quality of sevoflurane, including mass spectrometry and gas chromatography methods. These methods are practically tedious and need sophisticated apparatus. In the present work, an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometric method was used for the quantitative determination of sevoflurane which is characterized as a fast, accurate, and available technique for most pharmaceutical laboratories, besides the gas chromatographic method which is the most suitable for the detection of impurities. Sevoflurane is a liquid and it is applied directly on the glass top of the ATR-FTIR either as a concentrated solution or diluted with hexane as a diluent, which did not interfere with sample determination within the specified wavelength range of the IR spectrum, particularly the wavelength of the ethereal group at 1200 cm-1. This method can be applied to the identification test and quantitative assay of sevoflurane since it is validated for the precision, accuracy, reproducibility, and specificity in the analysis of sevoflurane as a pharmaceutical product. However, still, there is a need for a gas chromatographic method to detect the impurities and degradation products during the stability study of sevoflurane.

The non-edible and disposable parts of oyster mushroom, as novel adsorbent for quantitative removal of atrazine and its degradation products from synthetic wastewater.

In this study, the non-edible part of oyster mushroom was utilized for quantitative removal of the most commonly used s-triazine herbicide; atrazine and its breakdown products including deethylatrazine (DEA), hydroxyatrazine (ATOH) and deisopropylatrazine (DIA) from aqueous samples. The functional groups available on the oyster mushroom were studied applying FTIR before and after adsorption. Experimental parameters influencing the uptake process including acidity, sorbent mass, sorption time, initial analyte quantities, and agitation speed were analysed and the maximum removal was found at 4, 0.3 g, 120 min, 0.5 mg L-1, and 150 rpm, respectively. Accordingly, the adsorption capacities of 0.994, 1.113, 0.991 and 1.016 mg g-1 were obtained for DIA, DEA, ATOH and atrazine, respectively. The adsorption characteristics were discussed utilizing Langmuir and Freundlich isotherm models. The fundamental characteristic of the Langmuir isotherm, which can be elaborated using separation factor or equilibrium parameter, RL, and coefficient of variation, R2, were (0.761, 0.996), (0.884, 0.975), (0.908, 0.983) and (0.799, 0.984) for DIA, DEA, ATOH and Atrazine, respectively. These findings showed that all analytes' adsorption processes were fitted well to the Langmuir adsorption isotherm, indicating that the adsorbent surface was covered in a monolayer. The kinetics was also evaluated using the pseudo-first and pseudo-second order models. The coefficient of determination, r2, were found to be 0.09703, 0.9989, 0.9967 and 0.9998 for DIA DEA, ATOH and atrazine, respectively, for pseudo-second order, signifying that, all analytes were found to follow the pseudo-second order rate model showing that the rate limiting step is chemisorption in the sorption process. Based on these findings, the non-edible and disposable part of the oyster mushrooms can be utilized as a preferred alternative biosorbent for the uptake of the target compounds analysed and other pollutants possessing comparable physicochemical characteristics occurring in various water bodies.

Rapid removal of decabromodiphenyl ether by mechanochemically prepared submicron zero-valent iron with FeC2O4·2 H2O layers: Kinetics, mechanisms and pathways.

The utilization of nano zero-valent iron (nZVI) in polybrominated diphenyl ethers remediation has been studied extensively. However, challenges in balancing cost and reactivity have been encountered. A submicron zero-valent iron coated with FeC2O4·2 H2O layers (OX-smZVI) was synthesized via a mechanochemical method, aiming to resolve this contradiction. Characterization via SEM, TEM, and XPS confirmed the structure as FeC2O4·2 H2O coated iron lamellate with a surface area 24-fold higher than ball-milled zero-valent iron (smZVI). XRD highlighted an Fe/C eutectic in OX-smZVI, boosting its electron transfer capacity. Decabromodiphenyl ether degradation by OX-smZVI follows a two-stage process, with initial degradation by FeC2O4·2 H2O and a subsequent phase dominated by electron transfer. OX-smZVI exhibits a 4.52-34.40 times faster BDE209 removal rate than nZVI and scaled-up OX-smZVI displayed superior reactivity with preparation costs only 1/680 of nZVI. Given its enhanced reactivity and cost-efficiency, OX-smZVI emerges as a promising replacement for nZVI.

Residual behavior of dinotefuran and its metabolites during Huangjiu fermentation and their effects on flavor.

Yellow rice wine (Huangjiu) is a traditional Chinese alcoholic beverage. However, there is a risk of pesticide residues in Huangjiu due to pesticide indiscriminate use. In this study, the residues of dinotefuran and its metabolites during Huangjiu fermentation and their effects on flavor substances were studied. The initial concentrations of dinotefuran ranged from 856.3 to 1874.9 µg/L, and its half-life was no more than 3.65 d. At 24 d of Huangjiu fermentation, the terminal residues of dinotefuran, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN) were 195.1-535.3 µg/L, 38.33-48.70 µg/L and 37.8-74.1 µg/L, respectively. Twenty potential degradation compounds were identified by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS), and their toxicity was evaluated. Finally, the effect of dinotefuran on physicochemical properties and total phenol content of Huangjiu were analyzed. The risk of rancidity was significantly increased and bitter amino acids were formed. These findings provide a guidance and the safe production of Huangjiu.