Degradation Products Research Articles

In vitro safety evaluation of (6-methoxy-9-oxo-9H-xanthen-2-yl)methyl (E)-3-(2,4-dimethoxyphenyl)acrylate (K-116) – the novel potential UV filter designed by means of a double chromophore strategy

The use of topical photoprotection is necessary to reduce adverse effects caused by excessive exposure to ultraviolet radiation. Despite the high standards set for UV filters, many of them may contribute to the occurrence of adverse effects. The newly synthesised compound K-116, the (E)-cinnamoyl xanthone derivative, could be an alternative. We conducted extended in vitro safety evaluation of compound K-116. The research included assessment of irritation potential on skin tissue, evaluation of penetration through the epidermis, and assessment of phototoxicity, and mutagenicity. Additionally, the eco-safety of compound K-116 was evaluated, including an examination of its degradation pathway in the Cunninghamella echinulata model, as well as in silico simulation of the toxicity of both the parent compound and its degradation products. The research showed that compound K-116 tested in future application conditions is deprived of skin irritant potential additionally it does not penetrate through the epidermis. Results showed that K-116 concentrate is not phototoxic and not mutagenic. The eco-safety studies showed that it undergoes biodegradation in 27% in Cunninghamella echinulata model. The parent compound and formed metabolite are less toxic than reference UV filters (octinoxate and octocrylene).

Insights into the photodegradation of decamethylammonium bromide (DDAB) under UV/H2O2 system: Photodegradation kinetic modeling, degradation mechanism and toxicity evaluation

Decamethonium bromide (DDAB), as a class of quaternary ammonium-based disinfectants (QACs), was widely used during the COVID-19 outbreak. The abuse of DDAB is harmful to the health of aquatic organisms. The UV/H2O2 process is popularly utilized for the removal of trace contaminants from aqueous environments. Thus, in this paper, DDAB was selected as the model of QACs, and the degradation kinetics were simulated by Kintecus software. It was indicated that the effect of the degradation efficiency of DDAB was dominated by [·OH]ss. The degradation efficiency of DDAB was greater than 95 % when [·OH]ss was higher than 1.04×10−12 M. The high dosages of H2O2 (>100 μM) and the less concentration of pollutants (<10 μM) were more beneficial to the degradation of DDAB. The high dosages of NOM and CO32- in the system scavenged ·OH and thereby inhibited the degradation of DDAB. The interference of Cl- on the degradation efficiency was negligible. Additionally, the optimal pH value for removing DDAB was between 4 and 7. Besides, the degradation pathway of DDAB was inferred by Density Functional Theory (DFT) and Ultra-high Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS). The results showed that the degradation of DDAB began with C-N bond breaking, then generated aldehydes, underwent demethylation reaction, and finally converted to low molecule weight molecules. The results of Ecological Structure Activity Relationships (ECOSAR) toxicity assessment demonstrated that the toxicity of all the degradation products was significantly low. Overall, this study provides theoretical basis for the removal of QACs in the aqueous environment.

Hydrogen production from Fraxinus mandshurica solid wood waste using FeCl3 as a non-precious metal Lewis acid catalyst: A comprehensive utilization approach

The efficient use of wood powder has become increasingly important for protecting the environment and addressing energy shortages. In this study, a proton exchange membrane electrolysis system was utilized to convert biomass into valuable industrial chemicals and hydrogen using ferric ions as redox mediators, reduced reaction costs. GC-MC analysis revealed that the degradation products are mainly consisted of aromatic carbonyl compounds, along with some alcohols, phenols, and alkanes. The degradation efficiency was found to be 55.6 %, and the Faraday’s hydrogen production efficiency exceeds 92.6 %. Moreover, Fe3+/Fe2+ redox mediators was recycled in the electrolysis system, maintaining high reactivity. This research introduces a new approach for the degradation of wood powder, offering potential for sustainable industrial production and a reduction in environmental impact.

Enhancing production of hydrogen and simultaneous degradation of ciprofloxacin over Sn doped SrTiO3 piezocatalyst

The combination of hydrogen production from water and degradation of organic pollutants into a single reaction system is an attractive and promising solution for renewable energy generation and wastewater treatment. Herein, the piezocatalytic production of hydrogen coupled with simultaneous piezocatalytic degradation of organic antibiotic (ciprofloxacin) was successfully achieved using Sn doped SrTiO3 as the highly efficient and robust piezocatalyst through harvesting vibration energy. Results showed that 5 mol% Sn doped SrTiO3 (SrSn0.05Ti0.95O3) showed the highest piezocatalytic production rate of hydrogen (101.46 μmol g−1h−1) in water. And SrSn0.05Ti0.95O3 also exhibited remarkable piezocatalytic activity in solution containing ciprofloxacin with 151.03 μmol g−1h−1 of H2 evolution rate and 77.5 % of ciprofloxacin degradation efficiency within 60 min. In this process, the doping of Sn largely enlarged the distorted structure and conductivity of SrTiO3 to improve the piezocatalytic activity, and the organic ciprofloxacin mainly acted as the electron donors to synergistically improve the reduction process for H2 evolution. This work establishes the relationships between the piezoelectric property and the piezocatalyst structure, and provides an approach of advanced piezocatalytic technology for wastewater treatment and renewable energy generation.

Degradation of methyl orange using hydrodynamic cavitation coupled with plasma oxidation and ultraviolet C

Combining multiple advanced oxidation processes (AOPs) is essential for the efficient treatment of dye wastewater. In this study, the degradation efficiencies of various oxidation methods, including hydrodynamic cavitation (HC), dielectric barrier discharge (DBD) plasma oxidation, ultraviolet C (UVC), and their combination HC + DBD + UVC, were investigated for Methyl Orange (MO). The photolysis of ozone (O3) and the degradation mechanism associated with HC + DBD + UVC were analyzed to elucidate the pathway of MO degradation. The results demonstrated that the combination of HC + DBD + UVC exhibited a significantly enhanced degradation efficiency compared to other process combinations, achieving a removal efficiency exceeding 91% within a 5-min timeframe. Optimal parameters for achieving a 99.5% degradation rate of 10 mg/L MO were determined as follows: pH 4, inlet pressure of 1.5 MPa, utilization of eight UV lamps with a power input of 46.11 W. During the degradation process, hydroxyl radicals (·OH) and ozone (O3) played crucial roles, while the incorporation of UV lamps effectively mitigated ozone (O3) emissions and enhanced the oxidation of ozone (O3). In conjunction with the analysis of degradation products using liquid chromatography-mass spectrometry, it is highly probable that the MO degradation pathway involves reductive cleavage of the azo bond through ·OH attack. Compared to other experimental methods in literature, HC + DBD + UVC exhibits significant advantages such as enhanced efficiency and absence of additives. This innovative approach offers a rapid and practical on-site solution for efficient MO dye wastewater treatment.

Biosynthesis and characterization of a novel supported nanocatalyst for the methylene blue dye photodegradation: Machine learning modeling and photocatalytic activity

The present work aims to evaluate the photocatalytic activity of an alternative supported nanocatalyst with copper oxide nanoparticles were the photoactive phase and the analcime nanozeolite as the catalytic support (CuO-NPs@nANA), and to carry out a Machine Learning (ML) study to propose a reaction pathway for the MB dye degradation under visible light. Two machine learning algorithms (RF and XGB) were used in the regression model development from scientific papers concerning MB degradation (by GC-MS) to identify the degradation products of the reaction. XGB algorithm resulted in the best predictive model (R² equals 0.88 and 0.89 for training and testing, RMSE = 33–37), confirming the obtention of carbon dioxide (m/z = 44), water (m/z = 18) and low-molar mass compounds at the final of MB degradation reaction. Moreover, 76.93 % MB removal was reported at pH 10, [MB] = 200 mg L−1 and [CuO-NPs@nANA] = 0.5 g L−1 after 180 min under visible light, with k = 0.0088 min−1. Feature importance study revealed that the response m/w was strongly dependent on pH and reaction time. Therefore, this work confirms the potentiality of machine learning algorithms to develop predictive models for the elucidation of the degradation reaction pathway of organic dyes through heterogeneous photocatalysis.

Research and Application of Temporary Plugging Agent Technology for High-Pressure Wells in Gas Storage Facilities

Before various construction of gas storage well, in order to ensure safety, the reservoir must be temporarily blocked, degassed by circulation and no gas in the well can be operated. There are many temporary plugging methods for oil and gas wells. This paper studies the more advanced micro mesh gel temporary plugging technology in the industry and its application in gas storage wells, which mainly solves the problems of poor degradation backflow effect and difficult permeability recovery caused by weak formation stability after temporary plugging of gas storage wells. Research points: (1) On the basis of ordinary gel, through the fusion with cross-linking agent with special structure, a micron network polymer with significant steric hindrance effect on water molecules is finally formed, which improves the strength and stability of the gel system. (2) Add hexamethylene tetramine, bisphenol propane, delayed cross-linking agent and stabilizer into the polymer aqueous solution. It is verified by laboratory tests that the micron mesh gel can be formed after constant temperature coagulation for 3h~70h at ambient temperature of 90°C~170°C. (3) The temperature resistance, permeability and gel breaking of micron mesh gel are tested in the laboratory, and the results can meet the construction requirements. (4) After the temporary plugging operation of Well Su 49K-2X in the gas storage reservoir of Huabei Oilfield is completed, the degradation products of gel breaking will flow back smoothly to ensure that the well can be put into normal injection and production quickly. The test results show that: (1) Micron mesh gel has the advantages of long plugging validity, high temperature resistance, low viscosity after gel breaking, no residue, thorough gel breaking, no formation plugging pollution, and no impact on the original reservoir permeability. It is a new green plugging technology suitable for deep buried high-temperature depleted oil and gas reservoirs. (2) Before construction, the well temperature shall be measured to conduct test injection, so as to prevent gas invasion from affecting the construction effect. The pump injection displacement is designed to be redundant, so as to prevent the low molecular solution from not reaching the design position in the well on time, and the formation of solid rubber plugs at other positions in the well from affecting the construction.

Application of luminescent Photobacterium Phosphoreum T3 for the detection of zearalenone and estimating the efficiency of their enzymatic degradation

Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, causes enormous economic losses in the food and feed industries. Simple, rapid, low-cost, and quantitative analysis of ZEN is particularly urgent in the fields of food safety and animal husbandry. Using the bioluminescent bacterium Photobacterium phosphoreum T3, we propose a bioluminescence inhibition assay to evaluate ZEN levels quickly. The limit of detection (LOD), limit of quantification (LOQ), and quantitative working range of this bioluminescence inhibition assay were 0.1 µg/mL, 5 µg/mL, and 5-100 µg/mL, respectively. The concentration-response curve of the bioluminescence inhibition rate and ZEN concentration was plotted within the range 5 to 100 μg/mL, as follows: y = 0.0069x2 – 0.0190x + 7.9907 (R2 = 0.9943, y is luminescence inhibition rate, x is ZEN concentration). First, we used the bioluminescence inhibition assay to detect the remaining ZEN in samples treated with purified lactonohydrolase ZHD101. The bioluminescence inhibition assay results showed a strong correlation with the HPLC analysis. Furthermore, we successfully evaluated the overall toxicity of samples treated with purified peroxidase Prx and H2O2 using the P. phosphoreum T3 bioluminescence inhibition assay. The results indicate that the degradation products of ZEN created by purified peroxidase Prx and H2O2 showed little toxicity to P. phosphoreum T3. In this study, a simple, rapid, and low-cost assay method of zearalenone by bioluminescent P. phosphoreum T3 was developed. The bioluminescence inhibition assay could be used to estimate the efficiency of enzymatic degradation of ZEN.

A Simple Validated LC-UV Method for the Simultaneous Determination of Brimonidine and Brinzolamide in the Presence of Brinzolamide's Degradation Product (Major Metabolite) in Rabbit Aqueous Humor.

A sensitive, specific, reliable and low-cost LC-UV method has been developed and validated for simultaneous quantification of brimonidine tartrate (BM) and brinzolamide (BZ) in rabbit aqueous humor (AH) in the presence of N-desethyl-brinzolamide (NDBZ); BZ is a major degradation product, and it is also considered to be its major metabolite. Dorzolamide hydrochloride (DZ) was used as an internal standard (IS). The analytes were extracted from rabbit AH samples by a simple pre-treatment utilizing ZnSO4.7H2O as a deproteinizing agent. The analytes were separated on a cyanopropyl Waters column (4.6 × 200mm, 5μm) with an isocratic mobile phase consisting of 25mM ammonium acetate pH4.5 (adjusted with 85% phosphoric acid):methanol:acetonitrile (94:4.5:1.5, v/v) at a flow rate of 1.0mLmin-1. The detection was done at 254nm. The lower limit of quantification in rabbit AH was 100.0ngmL-1. The method was validated according to EMA guidelines. The method was confirmed to be accurate, precise and linear over a range of 100.0-1000.0ngmL-1 for BM and BZ. The method developed herein is simple, safe, eco-friendly, rapid and accurately applied for the quantification of BM and BZ, along with the successful separation of NDBZ, which is considered as a potential irritant degradation product of BZ.

Machine learning is an effective method to predict the 3-month prognosis of patients with acute ischemic stroke

Background and objectivesUpwards of 50% of acute ischemic stroke (AIS) survivors endure varying degrees of disability, with a recurrence rate of 17.7%. Thus, the prediction of outcomes in AIS may be useful for treatment decisions. This study aimed to determine the applicability of a machine learning approach for forecasting early outcomes in AIS patients.MethodsA total of 659 patients with new-onset AIS admitted to the Department of Neurology of both the First and Second Affiliated Hospitals of Bengbu Medical University from January 2020 to October 2022 included in the study. The patient’ demographic information, medical history, Trial of Org 10,172 in Acute Stroke Treatment (TOAST), National Institute of Health Stroke Scale (NIHSS) and laboratory indicators at 24 h of admission data were collected. The Modified Rankine Scale (mRS) was used to assess the 3-mouth outcome of participants’ prognosis. We constructed nine machine learning models based on 18 parameters and compared their accuracies for outcome variables.ResultsFeature selection through the Least Absolute Shrinkage and Selection Operator cross-validation (Lasso CV) method identified the most critical predictors for early prognosis in AIS patients as white blood cell (WBC), homocysteine (HCY), D-Dimer, baseline NIHSS, fibrinogen degradation product (FDP), and glucose (GLU). Among the nine machine learning models evaluated, the Random Forest model exhibited superior performance in the test set, achieving an Area Under the Curve (AUC) of 0.852, an accuracy rate of 0.818, a sensitivity of 0.654, a specificity of 0.945, and a recall rate of 0.900.ConclusionThese findings indicate that RF models utilizing general clinical and laboratory data from the initial 24 h of admission can effectively predict the early prognosis of AIS patients.

Highly Efficient Separation of Ethanol Amines and Cyanides via Ionic Magnetic Mesoporous Nanomaterials.

Simple and efficient sample pretreatment methods are important for analysis and detection of chemical warfare agents (CWAs) in environmental and biological samples. Despite many commercial materials or reagents that have been already applied in sample preparation, such as SPE columns, few materials with specificity have been utilized for purification or enrichment. In this study, ionic magnetic mesoporous nanomaterials such as poly(4-VB)@M-MSNs (magnetic mesoporous silicon nanoparticles modified by 4-vinyl benzene sulfonic acid) and Co2+@M-MSNs (magnetic mesoporous silicon nanoparticles modified by cobalt ions) with high absorptivity for ethanol amines (EAs, nitrogen mustard degradation products) and cyanide were successfully synthesized. The special nanomaterials were obtained by modification of magnetic mesoporous particles prepared based on co-precipitation using -SO3H and Co2+. The materials were fully characterized in terms of their composition and structure. The results indicated that poly(4-VB)@M-MSNs or Co2+@M-MSNs had an unambiguous core-shell structure with a BET of 341.7 m2·g-1 and a saturation magnetization intensity of 60.66 emu·g-1 which indicated the good thermal stability. Poly(4-VB)@M-MSNs showed selective adsorption for EAs while the Co2+@M-MSNs were for cyanide, respectively. The adsorption capacity quickly reached the adsorption equilibrium within the 90 s. The saturated adsorption amounts were MDEA = 35.83 mg·g-1, EDEA = 35.00 mg·g-1, TEA = 17.90 mg·g-1 and CN-= 31.48 mg·g-1, respectively. Meanwhile, the adsorption capacities could be maintained at 50-70% after three adsorption-desorption cycles. The adsorption isotherms were confirmed as the Langmuir equation and the Freundlich equation, respectively, and the adsorption mechanism was determined by DFT calculation. The adsorbents were applied for enrichment of targets in actual samples, which showed great potential for the verification of chemical weapons and the destruction of toxic chemicals.

One stone two birds: Recycling of an agri-waste to synthesize laccase-immobilized hierarchically porous magnetic biochar for efficient degradation of aflatoxin B1 in aqueous solutions and corn oil

Aflatoxin B1 (AFB1) contamination of oils is a serious concern for the safety of edible oil consumers. Enzyme-assisted detoxification of AFB1 is an efficient and safe method for decontaminating oils, but pristine enzymes are unstable in oils and require modifications before use. Therefore, we designed a novel and magnetically separable laccase-carrying biocatalyst containing spent-mushroom-substrate (SMS)-derived biochar (BF). Laccase was immobilized on NH2-activated magnetic biochar (BF-NH2) through covalent crosslinking, which provided physicochemical stability to the immobilized enzyme. After 30 days of storage at 4 °C, the immobilized laccase (product named “BF-NH2-Lac”) retained ~95 % of its initial activity, while after five repeated cycles of ABTS oxidation, ~85 % activity retention was observed. BF-NH2-Lac was investigated for the oxidative degradation of AFB1, which exhibited superior performance compared to free laccase. Among many tested natural compounds as mediators, p-coumaric acid proved the most efficient in activating laccase for AFB1 degradation. BF-NH2-Lac demonstrated >90 % removal of AFB1 within 5.0 h, while the observed degradation efficiency in corn oil and buffer was comparable. An insight into the adsorptive and degradative removal of AFB1 revealed that AFB1 removal was governed mainly by degradation. The coexistence of multi-mycotoxins did not significantly affect the AFB1 degradation capability of BF-NH2-Lac. Investigation of the degradation products revealed the transformation of AFB1 into non-toxic AFQ1, while corn oil quality remained unaffected after BF-NH2-Lac treatment. Hence, this study holds practical importance for the research, knowledge-base and industrial application of newly proposed immobilized enzyme products.

“PAW” a smart analytical process assessing lipophilicity of solutes in mixtures

BackgroundThe analysis of mixtures of contaminants remains a challenging task in many fields, including water quality and waste management. For example, the degradation of industrial waste such as plastics, leads to complex mixtures with hundreds of organic contaminants and often non-referenced analytes. In such cases, non-targeted or effects-based analyses provide complementary information to classical targeted-analyses, regarding contaminants nature or properties (molecular mass, lability, toxicity). In this study, a novel analytical method is proposed to characterise mixtures of unknown organic contaminants, with a focus on the lipophilicity of solutes. ResultsThe proposed process, named “PAW“ (Partition of Aqueous Waste), aims at the quantification of octanol-water partition coefficients (POW) of mixed organic analytes. The process is based on sequential liquid-liquid partition equilibria. The output result is a lipophilicity histogram of the solutes, screened according to the chosen detection method. The process quantifies the distribution of analytes as a function of their octanol-water partition coefficients, without requiring any identification or prior knowledge. The PAW process is applicable with various detectors (UV–Visible, total carbon, liquid scintillation, etc.) allowing to focus on specific families of contaminants (e.g. organic solutes, colloids, 14C-bearing, etc.). Experimental proofs of concept are proposed, illustrating process implementation and possible fields of application. The first example deals with purity analysis of synthetic radiolabeled compounds. The second example aims the monitoring of cellulose degradation and quantification of the lipophilicity of degradation products. SignificanceThe PAW analytical process seems especially useful for characterisation of mixtures containing both hydrophilic and lipophilic compounds, e.g. neutral and ionizable organic contaminants, hardly characterisable simultaneously by chromatographic methods. It could be complementary to more detailed targeted or screening analysis of samples and effluents. For example it may help assessing the composition and environmental fate of mixtures of unknown analytes, thus facilitating waste management or mitigation strategies.

The diverse roles of bromide in the degradation of tinidazole during UV-LED/chlorine process at different wavelengths: Kinetics, radical contribution, and degradation pathway

Bromide (Br–) is widely present in aquatic environment and plays important roles in pollutant degradation during advanced oxidation processes. This work systematically investigated the effect of Br– on the degradation of tinidazole (TNZ) during ultraviolet light-emitting diode (UV-LED)/chlorine process at different wavelengths (265 and 365 nm). The observed pseudo-first-order constant (k') for the TNZ degradation during UV-LED (365 nm)/chlorine process in the presence of 0.4 mM Br– (0.1125 min−1) was 1.56 times that during UV-LED (365 nm)/chlorine process in the absence of Br–. However, the k' value during UV-LED (265 nm)/chlorine process was reduced by 49.=7 % in the presence of 0.4 mM Br–. At 0–0.4 mM Br−, elevated levels of hydroxyl radicals (HO·) and active bromine species promoted TNZ degradation during UV-LED (365 nm)/chlorine/Br– process, whereas reduced HO· concentration was the main reason for the inhibition of TNZ degradation during UV-LED (265 nm)/chlorine/Br– process. With increasing solution pH from 5.8 to 7.8, the k' value of both processes decreased in the presence of Br–. Meanwhile, the k' value increased with increasing chlorine dosage and decreased with increasing initial TNZ concentration during both processes in the presence of Br–. The presence of Cl− and HCO3– presented negligible effects on the degradation of TNZ. According to the density functional theory calculation and detected intermediates, the degradation pathway of TNZ during both processes in the presence of Br– was proposed. The toxicity evaluation demonstrated that some of the degradation products of TNZ presented lower predicted toxicity values than TNZ. Overall, this work provides a thorough insight into the role of Br– in TNZ degradation during UV-LED/chlorine process at different wavelengths.

Electro-stimulation modulates syntrophic interactions in methanogenic toluene-degrading microbiota for enhanced functionality

Syntrophy achieved via microbial cooperation is vital for anaerobic hydrocarbon degradation and methanogenesis. However, limited understanding of the metabolic division of labor and electronic interactions in electro-stimulated microbiota has impeded the development of enhanced biotechnologies for degrading hydrocarbons to methane. Here, compared to the non-electro-stimulated methanogenic toluene-degrading microbiota, electro-stimulation at 800 mV promoted toluene degradation and methane production efficiencies by 11.49 %-14.76 % and 75.58 %-290.11 %, respectively. Hydrocarbon-degrading gene bamA amplification and metagenomic sequencing analyses revealed that f_Syntrophobacteraceae MAG116 may act as a toluene degrader in the non-electro-stimulated microbiota, which was proposed to establish electron syntrophy with the acetoclastic methanogen Methanosarcina spp. (or Methanothrix sp.) through e-pili or shared acetate. In the electro-stimulated microbiota, 37.22 ± 4.33 % of Desulfoprunum sp. (affiliated f_Desulfurivibrionaceae MAG10) and 58.82 ± 3.74 % of the hydrogenotrophic methanogen Methanobacterium sp. MAG74 were specifically recruited to the anode and cathode, respectively. The potential electrogen f_Desulfurivibrionaceae MAG10 engaged in interspecies electron transfer with both syntroph f_Syntrophobacteraceae MAG116 and the anode, which might be facilitated by c-type cytochromes (e.g., ImcH, OmcT, and PilZ). Moreover, upon capturing electrons from the external circuit, the hydrogen-producing electrotroph Aminidesulfovibrio sp. MAG60 could share electrons and hydrogen with the methanogen Methanobacterium sp. MAG74, which uniquely harbored hydrogenase genes ehaA-R and ehbA-P. This study elucidates the microbial interaction mechanisms underlying the enhanced metabolic efficiency of the electro-stimulated methanogenic toluene-degrading microbiota, and emphasizes the significance of metabolic and electron syntrophic interactions in maintaining the stability of microbial community functionality.

Bioinspired Carbon Dots-Based Fluorescent Sensor for the Selective Determination of a Potent Anti-Inflammatory Drug in the Presence of Its Photodegradation Products.

Herein, we synthesized biogenic carbon dots (CDs) with blue-shifted maximum excitation (λex/λem of 320/404 nm) from largely wasted tangerine seeds for the first time via a one-step hydrothermal method. The biogenic CDs exhibit a maximum excitation wavelength that overlaps with the absorption spectrum of ketorolac tromethamine (KETO) at 320 nm. The developed CDs serve as a turn-off fluorescent probe via an inner filter effect (IFE) quenching mechanism. The resulting CDs have high quantum yield (QY) (39% ± 2.89%, n = 5) and exhibited great performance toward KETO over a concentration range of 0.50-16.00 μg/mL with a limit of detection (LOD) = 0.17 μg/mL. The nanoprobe achieved a high % recovery in assaying KETO in tablet dosage form and had not been significantly affected by various interferents including co-formulated and co-administered drugs. The nanoprobe shows selectivity toward KETO, even in the presence of its photocatalytic degradation products. It can effectively investigate the elimination of KETO from aquatic systems and test its stability in pharmaceutical preparations. The developed nanoprobe underwent a comprehensive evaluation of its environmental impact using analytical eco-scale (AES), complex green analytical procedure index (Complex GAPI), and the Analytical GREEnness calculator (AGREE). The sustainability of the developed nano sensor was assessed and compared to the reported metal-based quantum dots probe for KETO using the innovative RGB 12 model, considering 12 white analytical chemistry (WAC) perspectives.

Construction of Ultrathin BiVO4‐Au‐Cu2O Nanosheets with Multiple Charge Transfer Paths for Effective Visible‐Light‐Driven Photocatalytic Degradation of Tetracycline

AbstractIn this study, unique BiVO4‐Au‐Cu2O nanosheets (NSs) are well designed and multiple charge transfer paths are consequently constructed. The X‐ray photoelectron spectroscopy measurement during a light off‐on‐off cycle and redox capability tests of the photo‐generated charge carriers confirmed the formation of Z‐scheme heterojunction, which can facilitate the charge carrier separation and transfer and maintain the original strong redox potentials of the respective component in the heterojunction. The ultrathin 2D structure of the BiVO4 NSs provided sufficient surface area for the photocatalytic reaction. The local surface plasmon resonance (LSPR) effect of the electron mediator, Au NPs, enhanced the light absorption and promoted the excitation of hot electrons. The multiple charge transfer paths effectively promoted the separation and transfer of the charge carrier. The synergism of the abovementioned properties endowed the BiVO4‐Au‐Cu2O NSs with satisfactory photocatalytic activity in the degradation of tetracycline (Tc) with a removal rate of ≈80% within 30 min under visible light irradiation. The degradation products during the photocatalysis are confirmed by using ultra‐high performance liquid chromatography‐mass spectrometry and the plausible degradation pathways of Tc are consequently proposed. This work paves a strategy for developing highly efficient visible‐light‐driven photocatalysts with multiple charge transfer paths for removing organic contaminants in water.

Exploring the potential of insect gut microbes for advancing renewable energy production

AbstractInsect gut microbes represent a rich source of enzymes and metabolic pathways that can be harnessed to advance renewable energy production. This review explores the potential of insect gut microbiota in the context of biomass degradation and biofuel production. Insects, particularly wood‐feeding species like termites and beetles, harbour complex microbial communities in their guts that efficiently break down lignocellulosic materials into simple sugars. These sugars can then be fermented into biofuels such as ethanol and methane. Recent research has focused on identifying key microbial species and enzymes involved in this process, as well as on engineering these microbes to enhance their efficiency and substrate specificity. Additionally, the ecological roles of these microbes in insect digestion and their potential for biotechnological applications beyond biofuel production are discussed. Overall, understanding and harnessing insect gut microbes holds great promise for advancing sustainable and renewable energy solutions.

Sunlight degradation of tetracycline by Z-type BiOI/g-C3N4 photocatalyst synthesized via a simple two-step process: Response surface methods, degradation pathways, toxicity evaluation

A method combining grinding and hydrothermal treatments was utilized to densely load three-dimensional BiOI onto two-dimensional g-C3N4, thereby preparing a BiOI/g-C3N4 photocatalyst with a Z-type heterojunction. Under varying climatic conditions throughout the year, 10%BiOI/g-C3N4 photocatalyst degraded 92.26 % of tetracycline (TC) under sunlight exposure in summer (sunny days) in 150 min, whereas it only degraded 47.33 % of TC under sunlight exposure in winter (cloudy days). The degradation parameters for TC by 10%BiOI/g-C3N4 were optimized using Response surface methods, establishing the optimal conditions for TC degradation (pollutant concentration of 10.94 mg/L, catalyst dosage of 31.34 mg, pH of 4.02), resulting in a degradation efficiency of 95.63 % for TC under the specified conditions. Employing HPLC-MS/MS and 3D EEM techniques, the degradation of TC primarily occurs due to the cleavage of its CC double bonds and CN bonds triggered by free radical attacks, and small molecular acids are produced during the degradation process. The impacts of TC solution treatment on plants were investigated, and the oxidative stress indicators MDA, SOD, POD, and CAT were assessed. The results demonstrated a decrease in all four indicators in plants cultured in TC degradation product solution, further affirming the applicability of 10%BiOI/g-C3N4 in practical scenarios.

Stability-indicating Reverse Phase-HPLC Method Development and Method Validation for Quantitative Determination of Degradation Products in Favipiravir API and Drug Product

Introduction: Favipiravir is an antiviral medication shown to be broad spectrum activity against RNA viruses, and potentially treating the COVID-19. Methodology: In this study, the HPLC method for the quantification of degradation impurities (Favipiravir Acid Impurities) were developed and validated for Favipiravir in Tablet dosage form. The specificity of the method was achieved in analytical column Agilent HPLC-C18, 5µm, (4.6 x250) mm. using a suitable mobile phase was 10 mM Phosphate buffer (pH 3.5 with orthophosphoric acid) and Acetonitrile in the Isocratic more of 70:30 v/v. The flow rate is 1.0 mL/min. the injection volume is 10 µL, detection at 320 nm in UV and total run time is 8.0 minutes. The samples were made for forced degradation under hydrolysis, oxidation, photolytic and thermal conditions. The method was validated for specific, selective, linear, robust and accurate as per the ICH guidelines. Results and Conclusion: The linearity of the method for Impurities and the analytes was found from 25 to 150 % concentration level with the correlation coefficient (r2) &gt; 0.999. The accuracy for impurity and the analytes was performed from 50 to 150% level concentration, and mean recovery was found from 98-102%. The analytical degradation and validated study results indicate its unstable nature in acidic, basic and thermal conditions. Therefore, this method is simple, selective and sensitive, this method can be used in pharmaceutical research and development and quality control departments.