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Photo-Catalytic Degradation of Trichlorophenol with UV/Sulfite/ZnO Process, Simultaneous Usage of Homogeneous Reductive and Heterogeneous Oxidative Agents generator as a New Approach of Advanced Oxidation/Reduction Processes (AORPs)
摘要： This study develops UV/Sulfite/ZnO (USZ) photoreactor, as a novel method of Advanced Oxidation/Reduction Processes (AORPs), and employs it for degradation, dechlorination and mineralization of 2,4,6-trichlorophenol (TCP) content of wastewaters. Degradation efficiency of the UV-only, UV/ZnO, UV/Sulfite and USZ processes were determined as 23.4%, 37.6%, 44.8% and 87.83% respectively, at 10 min reaction time, 50 mg L-1 TCP concentration and pH of 7. Findings indicated that TCP degrades completely within 15 min treatment of 50 mg L-1 initial TCP concentration. According to Molar ratio evaluations, 1:2:50 is the optimal Molar ratio of sulfite/ZnO/TCP in the USZ process. Analyzing effluents of the USZ reactor by liquid chromatography/mass spectroscopy after 5, 10 and 15 min reaction time revealed that TCP decomposes to ring-shaped compounds in less than 10 min and all TCP and its metabolites convert to linear compounds within 15 min reaction time. Also fourteen little fragments were identified in the degradation of TCP by USZ during 2.5 till 15 min of reaction time. Investigating kinetic of the process through a pseudo first-order model using 10 to 200 mg L-1 TCP over 1 to 15 min reaction time demonstrated that the observed rate constant (kobs) decreases from 0.3811 to 0.0824 min-1 and the observed TCP degradation rate (robs) increases from 3.811 to 16.48 mg L-1 min-1 with increase of TCP concentration. Furthermore, electrical energy consumption (EEO) of the USZ process was calculated with kinetic model 2.21 to 10.25 as 2.19 to 3.55 and with merit-figure model 4.94 to 12.39 kW h m-3 from 10 to 200 mg L-1, respectively. In addition, the effect of co-existing water anions on degradation of 50 mg L-1 TCP was explored during 30 min processing. While 100% degradation was achieved in the absence of any anion, adding nitrate, as the most effective anion, decreased TCP degradation to 78.24%. The highest dechlorination was observed at sulfite/ZnO Molar ratio 1:2 and pH 11.0. Mineralization of TCP by USZ process was achieved 33.2 % after 15 min of reaction.
关键词： Metabolites,Co-existing,Photoreactor,Degradation,Energy consumption,Kinetic
更新于2025-09-23 15:22:29
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New Derivatization Reagent for Detection of free Thiol-groups in Metabolites and Proteins in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging
摘要： Several diseases are associated with disturbed redox signaling and altered metabolism of sulfur-containing metabolites and proteins. Importantly, oxidative degradation of fresh-frozen tissues begins within the normal timescale of MALDI MSI sample preparation. As a result, analytical methods that preserve the redox state of the tissue are urgently needed for refined studies of the underlying mechanisms. Nevertheless, no derivatization strategy for free sulfhydryl groups in tissue is known for MALDI MSI. Here, we report the first derivatization reagent, (E)-2-cyano-N-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)ethyl)-3-(4-hydroxyphenyl)acrylamide (CHC-Mal), for selective detection of free thiols using MALDI MSI. We performed in-situ derivatization of free thiol groups from thiol-containing metabolites such as glutathione and cysteine and reduced proteins such as insulin and imaged their spatial distribution in porcine and mouse xenograft tissue. Derivatization of thiol-containing metabolites with CHC-Mal for MALDI MSI was also possible when using aged tissue in the presence of excess reducing agents. Importantly, CHC-Mal-derivatized low mass-metabolites could be detected without the use of a conventional MALDI matrix.
关键词： redox signaling,sulfur-containing metabolites,MALDI MSI,derivatization reagent,free thiol-groups
更新于2025-09-23 15:21:01
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Co Incorporated Mesoporous Carbon Material Assisted Laser Desorption/Ionization Ion Source as an on-line Interface of in vivo Microdialysis Coupled with Mass Spectrometry
摘要： The combination of microdialysis and mass spectrometry (MS) provides the potential for rapidly monitoring diverse metabolites in vivo. Unfortunately, the high concentration of salt in biological microdialysates hindered the sensitive and on-line detection of these small molecular compounds. In this study, we synthesized Co incorporated mesoporous carbon material (Co-NC), and developed Co-NC assisted laser desorption/ionization (LDI) ion source as an on-line interface of in vivo microdialysis coupled with MS for direct analysis of diverse metabolites in microdialysates. The Co-NC could be used as matrix for surface assisted laser desorption/ionization mass spectrometry (SALDI MS) analysis of small molecular compounds, even under high concentration of salt conditions. The Co-NC possessed the adsorption ability for small molecular compounds, and it was believed that the adsorption ability of Co-NC might separate the analytes from the salt in microdialysates at a microscopic level, which might facilitate the desorption and ionization of the analytes and finally improved the salt-tolerance ability as matrix. Furthermore, the Co-NC assisted LDI ion source as a novel interface of in vivo microdialysis coupled with MS has been applied to the on-line monitoring of liver metabolites from the CCl4-induced liver injury rat model for the first time.
关键词： microdialysis,Co incorporated mesoporous carbon material,metabolites,mass spectrometry,laser desorption/ionization,salt-tolerance
更新于2025-09-23 15:19:57
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Phytochemical properties and antioxidant activity of Echinops persicus plant extract: green synthesis of carbon quantum dots from the plant extract
摘要： Echinops persicus is a species of Echinops that can be found in Europe and western Asia especially in Iran. In this paper, the phytochemical properties of Echinops persicus were thoroughly investigated and studied. In this way, total amounts of flavonoid, tannins, phenols, carotenoids, saponins, alkaloids, and anthocyanin were measured by various analytical methods. The major phenolic and flavonoid content was found in the root acetone and flower ethanolic extract of the plant. Also, major saponins and carotenoid contents was found in root and leaf of the plant. These measurements were also performed for root, leaf, and flower of the plant in various solvent extracts. The results indicated that Echinops persicus is a rich source of secondary metabolites. Also, the plant extract demonstrated a considerable antiradical activity, which evaluated qualitatively as well as quantitatively. The largest capacity to neutralize DPPH radicals was found for root water extract of Echinops persicus plant. Finally, the possibility of the plant extract was evaluated for the green preparation of carbon quantum dots (CQDs). As-prepared CQDs were characterized by TEM, HRTEM, UV–Vis, XRD, and EDX analyses.
关键词： Antioxidant,Echinops persicus,Secondary metabolites,Green preparation of CQDs,Carbon quantum dots
更新于2025-09-23 15:19:57
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In vivo diffusiona??weighted MRS using semia??LASER in the human brain at 3??T: Methodological aspects and clinical feasibility
摘要： Diffusion‐weighted (DW‐) MRS investigates non‐invasively microstructural properties of tissue by probing metabolite diffusion in vivo. Despite the growing interest in DW‐MRS for clinical applications, little has been published on the reproducibility of this technique. In this study, we explored the optimization of a single‐voxel DW‐semi‐LASER sequence for clinical applications at 3 T, and evaluated the reproducibility of the method under different experimental conditions. DW‐MRS measurements were carried out in 10 healthy participants and repeated across three sessions. Metabolite apparent diffusion coefficients (ADCs) were calculated from mono‐exponential fits (ADCexp) up to b = 3300 s/mm2, and from the diffusional kurtosis approach (ADCK) up to b = 7300 s/mm2. The inter‐subject variabilities of ADCs of N‐acetylaspartate + N‐acetylaspartylglutamate (tNAA), creatine + phosphocreatine, choline containing compounds, and myo‐inositol were calculated in the posterior cingulate cortex (PCC) and in the corona radiata (CR). We explored the effect of physiological motion on the DW‐MRS signal and the importance of cardiac gating and peak thresholding to account for signal amplitude fluctuations. Additionally, we investigated the dependence of the intra‐subject variability on the acquisition scheme using a bootstrapping resampling method. Coefficients of variation were lower in PCC than CR, likely due to the different sensitivities to motion artifacts of the two regions. Finally, we computed coefficients of repeatability for ADCexp and performed power calculations needed for designing clinical studies. The power calculation for ADCexp of tNAA showed that in the PCC seven subjects per group are sufficient to detect a difference of 5% between two groups with an acquisition time of 4 min, suggesting that ADCexp of tNAA is a suitable marker for disease‐related intracellular alteration even in small case–control studies. In the CR, further work is needed to evaluate the voxel size and location that minimize the motion artifacts and variability of the ADC measurements.
关键词： optimization,power calculation,repeatability,diffusion,reproducibility,metabolites
更新于2025-09-19 17:13:59
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Development of a high-coverage matrix-assisted laser desorption/ionization mass spectrometry imaging method for visualizing the spatial dynamics of functional metabolites in Salvia miltiorrhiza Bge
摘要： Pro?ling the spatial distributions and dynamic changes of metabolites in plant tissue is critical to elucidate the complex metabolic regulation during plant growth, development, and responses to abiotic or biotic stresses. In this study, we developed a high-coverage MALDI-MS imaging method to visualize the spatial locations of a wide spectrum of metabolites in Salvia miltiorrhiza Bge. 1,5-Diaminonaphthalene (DAN) and 1,1 (cid:3) -binaphthyl-2,2 (cid:3) -diamine (BNDM) were optimized as MALDI matrices in positive and negative ion modes respectively, due to their low background interference and high sensitivity. Moreover, a simple organic washing protocol using acetone was shown to signi?cantly improve the sensitivity of MALDI-MSI. Using this method, we successfully imaged the spatial locations of amino acids, phenolic acids, fatty acids, oligosaccharides, cholines, polyamines, tanshinones, and phospholipids in Salvia miltiorrhiza Bge. In addition, the distributions of some metabolites in Salvia miltiorrhiza Bge root and stem were found to exhibit good spatial match with plant tissue structure. Thus, our method provides a spatially-resolved way to map the plant metabolic networks and to understand the physiological roles of several plant metabolites.
关键词： Functional metabolites,MALDI imaging,High-coverage,Salvia miltiorrhiza Bge,Spatial dynamics
更新于2025-09-16 10:30:52
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Enhancement of On-tissue Chemical Derivatization by Laser-Assisted Tissue Transfer for MALDI MS Imaging
摘要： The development of on-tissue chemical derivatization methods for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of small endogenous metabolites in tissues has attracted great attention for their advantages in improving detection sensitivity and ionization efficiency of poorly ionized and low abundant metabolites. Herein, a laser-assisted tissue transfer (LATT) technique was developed to enhance on-tissue derivatization of small molecules. Using a focused blue laser, a thin-layer tissue film (~ 1 μm) was transferred to an acceptor slide from a 6 μm dry tissue section preliminarily coated with derivatization and matrix reagents. The acceptor slide with its ablated constituents was then imaged by MALDI MS. On-tissue chemical derivatization with amino-specific derivatization reagent 4-hydroxy-3-methoxycinnamaldehyde (CA) was carried out on LATT system. 20-235 folds increase in signal intensity for CA derivatized metabolites such as amino acids, neurotransmitters and dipeptides were observed from rat brain tissues in comparison with conventional incubation-based derivatization. This technique was further extended to derivatize steroids with Girard reagent T (GirT). The remarkable derivatization efficiency can mainly be attributed to the minimization of ion suppression effects due to the reduced thickness of tissue section and endogenous components. Additionally, shorter derivatization time with no obvious metabolite delocalization was achieved using LATT method. These results demonstrate the advantages of LATT in the enhancement of on-tissue derivatization for the more specific and sensitive imaging of small metabolites in tissues with MALDI MS.
关键词： on-tissue chemical derivatization,small metabolites,ion suppression effects,MALDI MS imaging,laser-assisted tissue transfer
更新于2025-09-11 14:15:04
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Identification and imaging of indole-3-carboxamide cannabinoids in hair using matrix-assisted laser-desorption/ionization mass spectrometry
摘要： Purpose Different kinds of new synthetic cannabinoids (SCs) have been continuously developed to evade drug monitoring. Segmental hair analysis offers a longer period for retrospective drug detection compared with blood or urine. In this study, matrix-assisted laser-desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometric imaging (MALDI-FT ICR MSI) was developed for direct identification and imaging of synthetic indole-3-carboxamide cannabinoids in hair samples using the positive ion mode. Methods The target SCs include N-(adamantan-1-yl)-1-pentyl-1H-indole-3-carboxamide (APICA), N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide (5F-AB-PICA), N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-pentyl-1H-indazole-3-carboxamide (ADB-PINACA) and N-(1-amino -3,3-dimethyl-1-oxobutan-2-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide (5F-ADBICA). The MALDI-MS and MS/MS were first performed on the scraped hair soaked in a mixture of the four SCs after matrix sublimation. This method may provide a detection power for SCs to the 0.1 ng level per 2 cm hair. Target cannabinoids were identified by MS1 and MS2. Matrix deposition methods including airbrush sprayer and sublimation were compared. Results The method was then applied in revealing the spatial distribution of APICA and 5F-ADBICA in real hair samples from two drug abusers by comparing MS1 and MS2 spectra. The metabolites of APICA and 5F-ADBICA were also presumed to be present in the positive hair samples. Furthermore, a comprehensive comparison between a MALDI-FT ICR MS and a MALDI time-of-flight–MS instrument was performed in detection-sensitivity and specificity for positive real samples. Conclusions The proposed method provides a powerful tool for drug supervision and forensic medicine analysis in a wide time window, and the sample amount required was also decreased.
关键词： Hair analysis,Synthetic cannabinoids,Metabolites,Matrix sublimation,Mass spectrometric imaging,Matrix-assisted laser-desorption/ionization
更新于2025-09-11 14:15:04
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Simultaneous determination of dissolved phenanthrene and its metabolites by derivative synchronous fluorescence spectrometry with double scans method in aqueous solution
摘要： A simple and sensitive derivative synchronous fluorescence spectrometry with double scans (DS-DSFS) method was developed for simultaneous determination of dissolved Phenanthrene (Phe) and its metabolites 1-hydroxy-2-naphthoic acid (1H2NA) and salicylic acid (SA) in aqueous solution. The value of 69 nm was selected as the optimal Δλ conditions for Phe and 1H2NA, and the Δλ value of 55 nm was selected for SA. The overlapping fluorescence emission spectra of Phe, 1H2NA and SA were resolved by DS-DSFS. The signals detected at wavelength of 296 nm for Phe, 352 nm for 1H2NA and 307 nm for SA vary linearly when the concentrations in the range of 4.0–1.0 × 103 μg L?1, 4.0–1.2 × 103 μg L?1 and 4.0–8.0 × 102 μg L?1, respectively. The detection limits were 0.08, 0.07 and 0.88 μg L?1 for Phe, 1H2NA and SA, with the relatively standard deviations less than 5.0%. The established method was successfully applied in the determination of Phe and the metabolites during the biodegradation of dissolved Phe in the lab. It was evidenced that the method has potential for the in situ investigation of PAH biodegradation.
关键词： Metabolites,PAHs,In situ,Derivative synchronous fluorescence spectrometry,Biodegradation
更新于2025-09-04 15:30:14