A method for the determination of vanillin, methyl vanillin and ethyl vanillin in edible vegetable oil by one-step purification combined with high performance liquid chromatography tandem mass ...spectrometry was established. A solid-phase micro-extraction one-step purification and impurity removal device was constructed based on the needle filter filled with MIL-101(Cr) material, and the purification process was quickly completed in the filter head with the help of syringe driving force. Under the optimized conditions of several factors affecting the extraction efficiency, the linear range was 0–500 ng/mL and the correlation coefficient (r) was greater than 0.9994. Under the six spiked concentrations, the recovery of edible vegetable oil was between 88.6% and 98.5%, and the RSDs were between 2.41% and 5.78%. The recoveries of inter-day and intra-day tests were 90.9%–93.0% and 90.6%–100.5%, respectively. The precision of inter-day and intra-day analysis were 6.09%–7.05% and 2.75%–4.49%, respectively. This method was used to detect 100 batches of commercial vegetable oil, only vanillin was detected, the detection rate was 52.0%, and the detection concentration was 107–872 μg/kg. The positive samples were confirmed by HPLC-QTOF/MS. The results showed that this method had the advantages of simple operation and high detection throughput, and was suitable for rapid analysis of vanillin, methyl vanillin and ethyl vanillin in different types of edible vegetable oil samples.
•MIL-101 (Cr) material was synthesized by hydrothermal reaction.•One-step purification of SPME based on MIL-101(Cr) was developed.•SPME procedure displayed highly efficient impurity removal capabilities.•One-step purification for vanillin compounds in oil samples was established.•The method delivered low LOQ, good recoveries and satisfactory precision.
Lignin is abundant and contains a large number of aromatic groups. Herein, CdxZn1-xS photocatalyst with tunable band gap energy was successfully synthesized by using 3-mercaptopropionic acid as a ...structure tuning additive. CdxZn1-xS can depolymerize alkaline lignin to vanillin by the photocatalytic process. Each gram of alkaline lignin can produce 46.5 mg of vanillin. 2-Phenoxy-1-phenylethanol (PP-ol) and other model compounds were used to understand the depolymerizing process of lignin. Fine tuned CdxZn1-xS can effectively cleave the Cβ-O-4 bond existed in PP-ol under simulated sunlight. The highest conversion of PP-ol was 89.5% with phenol and acetophenone yields of 66.2% and 33.5%, respectively. The mechanism studies confirm that the Cα-H in PP-ol and lignin is firstly dehydrogenated to form Cα radical intermediates, and then the photogenerated electrons break the adjacent Cβ-O bond. This research provides a new strategy to prepare valuable chemicals by virtue of renewable biomass and simulated sunlight.
•N-doped lignin-MOFs derived carbon catalyst was successfully prepared.•Co/CN-0.5–750 displayed the best vanillin hydrodeoxygenation performance.•The catalyst has good applicability for conversion of ...lignin-derived phenols.
Upgrading of lignin-derived bio-oil to value-added biofuel was of great significance for efficient utilization of renewable resources and reducing the use of fossil fuels. Hydrodeoxygenation (HDO) was considered to be a promising technology for the conversion of lignin-derived bio-oil. Herein, we reported a novel method for the preparation of lignin-MOF derived N-doped catalysts, which was then successfully introduced into the upgrading of lignin-derived phenols and lignin depolymerization. All catalysts were well characterized and Co/CN-0.5–750 exhibited excellent performance during the catalytic HDO process. The optimized catalyst demonstrated highly efficient active hydrogen generation from isopropanol. Moreover, it could afford the best vanillin (VAN) conversion (100 %) and highest 2-Methoxy-4-methylphenol (MMP) yield (92 %) under the mild reaction conditions (180 °C, 0.5 MPa nitrogen, 2 h). It was confirmed that the excellent performance was related to nitrogen doping. This study could provide some useful insights for the hydrodeoxygenation of lignin and its derivative.
Vanillin finds widespread applications in various industries, such as food, pharmaceuticals, and cosmetics. However, excessive intake of vanillin could pose risks to human health. This study detailed ...the successful creation of a heterojunction of branched benzopyrazine-based polymers coating on graphene (CMP-rGO) through the Sonogashira-Hagihara coupling reaction. Utilizing the CMP-rGO, a novel electrochemical sensor for vanillin detection was developed. Besides, the synthesized materials were validated using standard characterization techniques. Both cyclic voltammetry and differential pulse voltammetry techniques were employed to investigate vanillin's electrochemical characteristics on this sensor. The findings indicated a significant enhancement in vanillin's electrochemical signal responsiveness with the application of CMP-rGO. Under optimal conditions, the sensor demonstrated a linear response to vanillin concentrations ranging from 0.08 to 33 μM and achieved a detection limit as low as 0.014 μM. Also, the constructed electrochemical sensor exhibited excellent selectivity, stability, and reproducibility. It has been effectively employed to detect vanillin in real samples such as human serum, human urine, and vanillin tablets, with a recovery rate of 99.13–103.6 % and an RSD of 3.46–1.26 %. Overall, this innovative sensor offers a novel approach to the efficient and convenient detection of vanillin.
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•A benzopyrazine-based polymer coating on graphene (CMP-rGO) was synthesized.•CMP-rGO was used in the electrochemical sensor for vanillin detection.•The electrochemical sensor successfully detected vanillin in the actual samples.•This study expanded the application of CMP-rGO to electrochemical sensors.
•The Pd/α-MoC catalyst demonstrates an overwhelming selectivity to MMP.•Water treatment induces the formation of a thin layer of MoO3 on catalyst surface.•The heterogeneous layer significantly ...increases the acidity of modified catalyst.•The unexpected activity is attributed to the synergy between Pd and MoC/MoO3 layer.
Selective hydrodeoxygenation of biomass and its derivatives to produce chemicals and biofuels is an effective upgrading strategy to achieve global sustainable development goals. Through the development and utilization of renewable resources, sustainable consumption and production patterns can be promoted and climate change and its impacts can be addressed. Herein, selective hydrodeoxygenation (HDO) of vanillin was conducted by utilizing a Pd/α-MoC catalyst modified with solvent water. The water modification induced the formation of a thin layer of molybdenum oxide on the Pd/α-MoC catalyst surface, which significantly promotes the selective hydrodeoxygenation of vanillin. The conversion of vanillin over the modified Pd/α-MoC catalyst reached 99.9 %, while the selectivity to 4-methyl-2-methoxyphenol (MMP) reached 99.9 % at 0.3 MPa H2 and 80 °C. Comprehensive characterizations elucidate that the heterogeneous layer on the surface of the modified catalyst significantly increases the acidity of the catalyst and improves the removal efficiency of hydroxyl groups, thus improving the high selectivity to the desired product. Moreover, the side reactions are inhibited due to the using of water as the solvent, which contributes a high carbon balance. The modified Pd/α-MoC catalyst exhibits efficient hydrodeoxygenation of vanillin under mild conditions, which suggests an avenue for chemical transformations of biomass derivatives into high value chemicals.
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•Biofilm in reverse osmosis membrane regulated by quorum sensing was investigated.•Surface modification versus direct dosing of quorum sensing inhibitors was compared.•Membrane ...surface modification with QSIs shows higher inhibitory effects on biofilm.•Chemical structure of vanillin and vanillin-analogues are crucial on QS inhibition.
Quorum sensing inhibitors (QSIs) have shown promising results in reducing biofouling in various membrane systems. Vanillin was shown to inhibit QS of gram-negative bacteria during water treatment. Here, four vanillin-analogues with various chemical structures were used to understand the QS mechanisms in biofilm reduction and to compare direct dosing and surface modification of the inhibitors. Biofilm reduction, evaluated based on the content of extracellular polymeric substances (EPS), was the greatest with vanillin (49%) and occurred to some extent with 4-hydroxybenzaldehyde (21%) and m-anisaldehyde (13%), when direct dosing was applied. Experiments using vanillin-analogues revealed crucial roles of the chemical structure and functional groups on the inhibition of biofilm formation. The aldehyde and hydroxyl groups in both vanillin and 4-hydroxybenzaldehyde might be essential for QS inhibition. Further, surface modification with interfacial polymerization and immobilization of QSIs was conducted to evaluate their anti-biofouling capabilities. Surface modification was markedly effective in reducing biofilm formation; the EPS content of biofilms formed on vanillin-incorporated membranes was reduced by 64%. Additionally, the modified membranes showed a water flux comparable to that of pristine membranes, showing little possibility to block membrane pores during modification procedures. These findings will aid the development of QSI-based techniques for biofouling mitigation.
•5CuO/Al2O3 catalysts can be prepared without hydrogen pre-treatment.•The strong interaction is beneficial for in situ reduction of catalysts.•Surface CuO species can be reduced to Cu0 and Cu+ in ...situ during the reaction.•The high catalytic activity be ascribed to the synergistic between Cu0 and Cu+.•Efficient hydrodeoxygenation of VN to MMP under mild conditions.
A new method for the hydrodeoxygenation of vanillin to 2-methoxy-4-methylphenol (MMP) by in-situ reduced CuO/Al2O3 catalysts was developed. The CuO/Al2O3 catalysts with different CuO contents were prepared by simple wet impregnation and could provide complete vanillin conversion with 99 % MMP selectivity under mild conditions (120 °C, 0.5 MPa H2, 8 h). The results from XPS and H2-TPR characterizations of the CuO/Al2O3 catalysts suggested that CuO species had a strong interaction with the Al2O3 support, which was beneficial for the in-situ reduction of CuO to Cu+ and Cu0 species during the hydrodeoxygenation reaction. The synergistic effect of Cu+ and Cu0 species was believed to promote the hydrodeoxygenation of vanillin, in which Cu0 accounts for the hydrogenation reaction, while Cu+ is responsible for the adsorption of vanillin and 4-hydroxy-3-methoxybenzyl alcohol to facilitate the further dehydration of 4-hydroxy-3-methoxybenzyl alcohol. In addition, the CuO/Al2O3 catalyst could maintain high catalytic activity after three reaction cycles and showed versatility for various lignin derivatives. The development of this in-situ reduceable catalyst could provide a cost-effective approach for the upgrading of biomass derived products.
The production of chemicals/products so far relies on fossil-based resources with the creation of several environmental problems at the global level. In this situation, a sustainable and circular ...economy model is necessitated to mitigate global environmental issues. Production of biowaste from various processing industries also creates environmental issues which would be valorized for the production of industrially important reactive and bioactive compounds. Lignin acts as a vital part in biowaste composition which can be converted into a wide range of phenolic compounds. The phenolic compounds have attracted much attention, owing to their influence on diverse not only organoleptic parameters, such as taste or color, but also active agents for active packaging systems. Crop residues of varied groups, which are an affluent source of lignocellulosic biomass could serve as a renewable resource for the biosynthesis of ferulic acid (FA). FA is obtained by the FA esterase enzyme action, and it can be further converted into various tail end phenolic flavor green compounds like vanillin, vanillic acid and hydroxycinnamic acid. Lignin being renewable in nature, processing and management of biowastes towards sustainability is the need as far as the global industrial point is concerned. This review explores all the approaches for conversion of lignin into value-added phenolic compounds that could be included to packaging applications. These valorized products can exhibit the antioxidant, antimicrobial, cardioprotective, anti-inflammatory and anticancer properties, and due to these features can emerge to incorporate them into production of functional foods and be utilization of them at active food packaging application. These approaches would be an important step for utilization of the recovered bioactive compounds at the nutraceutical and food industrial sectors.
