Month: December 2022

Ncube, Somandla published the artcileDetermination of volatile compounds during deterioration of African opaque beer using a stir bar sorptive extraction technique and gas chromatography-high resolution mass spectrometry, Application In Synthesis of 123-29-5, the main research area is Opaque beer volatile compound SBSE GC HRT; (HS)-SPME, (headspace)-solid phase microextraction; Beer deterioration; CIS, cooled injection system; GC-HRT, gas chromatography-high resolution time-of-flight mass spectrometry; Gas chromatography-high resolution mass spectrometry; Opaque beer; PDMS, polydimethylsiloxane; SBSE, stir bar sorptive extraction; Stir bar sorptive extraction; TDU, thermal desorption unit; Volatile compounds.

Opaque beer traditional to African communities undergoes quick deterioration and is consumed within 7 days of its production The current study has utilized a stir bar sorptive extraction technique followed by GC-HRT determination to trace variations of 84 volatile compounds in four opaque beers commonly brewed in South Africa over the 7-day shelf life period. The major fruity esters were observed to increase up to Day 4 and eventually decreasing until Day 7 where their levels were finally lower than Day 1. Aldehydes reduced drastically and were less than 50% on Day 2 and becoming almost undetectable at Day 7. The common beer alcs. (phenylethyl alc. and 3-methyl-1-butanol) decreased during beer shelf life while phenolics with undesirable medicinal tastes (creosol and p-cresol) increased up to 24-fold by Day 7. This study might open future research perspectives around opaque beer traditional to African rural communities.

Current Research in Food Science published new progress about Adsorption. 123-29-5 belongs to class esters-buliding-blocks, name is Ethyl nonanoate, and the molecular formula is C11H22O2, Application In Synthesis of 123-29-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zainol, Muzakkir Mohammad published the artcileBio-fuel additive synthesized from levulinic acid using ionic liquid-furfural based carbon catalyst: Kinetic, thermodynamic and mechanism studies, Formula: C7H12O3, the main research area is biofuel levulinic acid ionic liquid carbon catalyst thermodn kinetics.

The Et levulinate is one of promising platform chem. from biomass and commonly involved the esterification reaction of levulinic acid. The reactions are extensively focussed on the catalytic performance by various catalysts and presented limited work on the kinetic, thermodn. and mechanism study for heterogeneous catalyst reaction. To fill this gap, the reaction anal. over a new ionic liquid-furfural carbon catalyst has been investigated in this work. The math. equations were derived to determine the kinetic-thermodn. parameters, and proposed suitable mechanism for the reaction. Pseudo-first order model presents high correlation coefficient and accuracy with the reaction rate constant of 0.0037-0.0127 min-1 and Ea = 17.3 kJ/mol. The reaction is endothermic and non-spontaneous with ordered system at transition state. The proposed combined nucleophilic substitution and Eley-Rideal mechanism is comprised of SN2 steps and heterogeneous catalytic reaction. The results provide insights on the reaction for future designing and scaling-up the esterification process.

Chemical Engineering Science published new progress about Adsorption. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Formula: C7H12O3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Samantaray, Paresh Kumar published the artcile‘Template-free’ hierarchical MoS2 foam as a sustainable ‘green’ scavenger of heavy metals and bacteria in point of use water purification, Category: esters-buliding-blocks, the main research area is molybdenum sulfide heavy metal bacteria.

Molybdenum disulfide (MoS2), with its unique optical and elec. properties, has been explored for a variety of applications in the recent past. Still, its capabilities in point-of-use heavy metal ion removal remain to be explored. Herein, for the first time using a facile approach, we fabricated three-dimensional (3D) MoS2 foam from exfoliated single to few-layered MoS2 sheets for the selective exclusion of heavy metals and stringent bactericidal response. This foam was able to exclude 99.9% of Pb(II) and 98.7% of As(III) instantaneously and reduced more than 98% of bacteria E. coli. Moreover, the foam exhibits selective toxicity towards bacterial cells while showing no observable toxicity towards mammalian cells. The foam can be recycled and reused for at least five cycles under accelerated conditions and thus can be used for a promising non-cytotoxic, facile, and environmentally benign process for inline water remediation to remove heavy metal ions from the feed and as a potential antibacterial agent.

Nanoscale Advances published new progress about Adsorption. 2044-85-1 belongs to class esters-buliding-blocks, name is 2′,7′-Dichloro-3-oxo-3H-spiro[isobenzofuran-1,9′-xanthene]-3′,6′-diyl diacetate, and the molecular formula is C24H14Cl2O7, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Khan, Ihtisham Wali published the artcileBiodiesel production by valorizing waste non-edible wild olive oil using heterogeneous base catalyst: Process optimization and cost estimation, Related Products of esters-buliding-blocks, the main research area is biodiesel valorizing waste wild olive oil heterogeneous base catalyst.

The current research investigates sustainable biodiesel production from non-edible wild olive oil via novel Na/SiO2/TiO2 heterogeneous catalyst. The catalyst was synthesized by Sol-Gel and wet impregnation method. Furthermore, the designed catalyst was evaluated by various spectroscopic techniques like SEM, EDX, XPS, FTIR, BET and XRD. The impact of various influencing parameters such as catalyst loading, reaction temperature, oil/methanol molar ratio and reaction time were scrutinized and the maximum 97% yield was achieved at the reaction conditions of 1:20 WOSO/MeOH molar ratio, 9 wt% catalyst loading at 70°C and 120 min of reaction time. The synthesized biodiesel was confirmed from GC-MS anal., whereas the various physiochem. properties of synthesized biodiesel were explored by ASTMD 5761 and EN 1404 methods. The plausible reaction mechanism of Na/SiO2/TiO2 catalyzed WOSO was also proposed. Finally, the cost estimation of the designed catalyst investigates its com. viability for low cost biodiesel production using non-edible WOSO feedstock.

Fuel published new progress about Adsorption. 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, Related Products of esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Khan, Ihtisham Wali published the artcileBiodiesel production by valorizing waste non-edible wild olive oil using heterogeneous base catalyst: Process optimization and cost estimation, Application In Synthesis of 111-11-5, the main research area is biodiesel valorizing waste wild olive oil heterogeneous base catalyst.

The current research investigates sustainable biodiesel production from non-edible wild olive oil via novel Na/SiO2/TiO2 heterogeneous catalyst. The catalyst was synthesized by Sol-Gel and wet impregnation method. Furthermore, the designed catalyst was evaluated by various spectroscopic techniques like SEM, EDX, XPS, FTIR, BET and XRD. The impact of various influencing parameters such as catalyst loading, reaction temperature, oil/methanol molar ratio and reaction time were scrutinized and the maximum 97% yield was achieved at the reaction conditions of 1:20 WOSO/MeOH molar ratio, 9 wt% catalyst loading at 70°C and 120 min of reaction time. The synthesized biodiesel was confirmed from GC-MS anal., whereas the various physiochem. properties of synthesized biodiesel were explored by ASTMD 5761 and EN 1404 methods. The plausible reaction mechanism of Na/SiO2/TiO2 catalyzed WOSO was also proposed. Finally, the cost estimation of the designed catalyst investigates its com. viability for low cost biodiesel production using non-edible WOSO feedstock.

Fuel published new progress about Adsorption. 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Application In Synthesis of 111-11-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Aszyk, Justyna published the artcileConcentration levels of selected analytes in the gas phase of an e-cigarette aerosol, Related Products of esters-buliding-blocks, the main research area is electronic cigarette gas phase aerosol.

The aerosols generated from e-cigarettes are composed of liquid and gas phases resulting from vaporized e-liquid The apportioning of substances from e-liquid into the liquid and gas phases during e-cigarette use has not been extensively studied. Partitioning of e-liquid components between the gas and the liquid phase of the aerosol influences the substances inhaled and exhaled by the users, leading to second-hand exposure. It seems important to determine which compounds and how much of them are transferred into the gas phase and may immediately enter the bloodstream. For this purpose, a method based on thermal desorption followed by gas chromatog. coupled with tandem mass spectrometry (GC-MS/MS) in electron ionization mode was developed. As in a previous study, an automatic generator of an aerosol from an e-cigarette with a collection tube filled with melt-blown non-woven fabric disks and equipped with Tenax TA sorption tubes was used. The melt-blown non-woven fabric is designed to capture liquid phase compounds, while sorption tubes are meant to sorb compounds in the gas phase of the aerosol. To control the e-liquid mass changes before and after a puff session, quantitation based on the mass change tracking approach (MCT) was applied. Accuracy of the developed method ranged between 91% and 110% regardless of the spiking level, with precision and reproducibility better than 10%. The limits of detection (LODs) ranged from 0.015 to 0.076 ng of substance emitted/mg of consumed e-liquid, while limits of quantitation (LOQs) ranged from 0.045 to 0.23 ng of substance emitted/mg of consumed e-liquid Most of the compounds are deposited in the liquid phase of the aerosol, while only trace levels of some substances may be observed in an actual, non-condensed gas phase.

Microchemical Journal published new progress about Adsorption. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Related Products of esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Jaoued-Grayaa, Najeh published the artcileDesign of molecularly imprinted polymer materials relying on hydrophobic interactions, Formula: C16H30O2, the main research area is acrylic molecularly imprinted polymer crosslinking hydrophobic silica adsorption kinetics.

The design of molecularly imprinted polymers (MIPs) for the specific binding of hydrophobic mols. (mitotane) was investigated by considering monomers and crosslinking agents with variable hydrophobic character, Me methacrylate, Bu methacrylate and lauryl methacrylate as functional monomers, and ethylene glycol dimethacrylate and 1,6-hexanediol dimethacrylate as crosslinking agents. MIPs were bound to a porous silica support by means of a radical transfer reaction with grafted 3-mercaptopropyl groups. Equilibrium adsorption isotherms to molecularly imprinted and non-imprinted materials were modeled with the Volmer and Langmuir-Volmer isotherms, giving the thermodn. parameters of adsorption. The most hydrophobic monomer provided the highest selective adsorption although strong non-selective adsorption and the intrinsic softness of poly(lauryl methacrylate) is detrimental to selectivity. Adsorption was exothermic with a predominant enthalpic contribution. Adsorption kinetics were fast due to the high accessibility of mol. imprints on the surface of the thin MIP layer coating the porous silica support.

Colloids and Surfaces, A: Physicochemical and Engineering Aspects published new progress about Adsorption. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Formula: C16H30O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhao, Deyang published the artcileInsights into bimetallic synergistic effect towards γ-valerolactone production under Co doped Zr-TiO2, HPLC of Formula: 539-88-8, the main research area is titanium oxide valerolactone production structural optical property.

Co doped into 5% Zr-TiO2 (Co@5% Zr/-TiO2) was prepared by a simple, facile sol-gel method, and employing in the catalytic transfer hydrogen (CTH) process starting from Et levulinate (EL) to γ-valerolactone (GVL). Lewis/Bronsted acid ratio and BET surface area increased with the incorporation of Co into Ti-Zr-O support. In addition, the synergistic effect between Co-Zr in TiO2 enhanced the strong acid strength sites. Co@5% Zr-TiO2 exhibited the highest catalytic performance (EL conversion 95%, GVL yield 88%) under optimum condition (0.2 M EL, 15 mL 2-PrOH, 190°C, 11 h). Noticeably, Co@5% Zr-TiO2 exhibited higher stability in 4th recycling experiments as compared to 5% Zr-TiO2 under identical condition. From computational calculation, EL adsorption process was more spontaneous with ΔEad= -8.240 eV. The protonation process made the reactants get close to the surface with a bonded O12-Ti2.179 Å and O6-Zr of 2.376 Å. Finally, GVL showed a strong leaving trend after the formation.

Molecular Catalysis published new progress about Adsorption. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, HPLC of Formula: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Riboni, N. published the artcileA simple and efficient Solid-Phase Microextraction – Gas Chromatography – Mass Spectrometry method for the determination of fragrance materials at ultra-trace levels in water samples using multi-walled carbon nanotubes as innovative coating, HPLC of Formula: 6259-76-3, the main research area is fragrance material multiwalled CNT SPE GC MS water pollution; Emerging contaminants; Fragrance materials; Multi-walled carbon nanotubes; Personal care products; Solid-phase microextraction; Water sample.

The occurrence of emerging contaminants is becoming of increasing importance to assess the impact of anthropogenic activities onto the environment. The present study reports for the first time the development and validation of an efficient method for the simultaneous determination of fragrance materials in water samples based on the use of a novel multiwalled carbon nanotubes (MWCNTs)-based solid-phase microextraction coating. Helical MWCNTs were selected as adsorbent material due to their outstanding extraction performance. The multicriteria method of desirability functions allowed the optimization of the exptl. conditions in terms of extraction time and extraction temperature Validation proved the reliability of the method for the determination of the analytes at ultra-trace levels, obtaining detection limits in the 0.2-13 ng/L range, good precision, with relative standard deviations lower than 20% and recovery rates in the 80 ± 12%-111 ± 11%. Superior enrichment factors compared to com. fibers were also calculated Finally, applicability to real sample anal. was demonstrated.

Talanta published new progress about Adsorbents. 6259-76-3 belongs to class esters-buliding-blocks, name is Hexyl 2-hydroxybenzoate, and the molecular formula is C13H18O3, HPLC of Formula: 6259-76-3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Mohan, Akhil published the artcileLiquid fuel from waste tires: novel refining, advanced characterization and utilization in engines with ethyl levulinate as an additive, Product Details of C7H12O3, the main research area is ethyl levulinate additive liquid fuel waste tire engine.

Pyrolysis is a promising thermochem. strategy to convert scrap tires into diesel-like fuels. Crude tire pyrolysis oil (CTPO) was produced in a 10 ton rotating autoclave reactor by thermal depolymerization of the tire polymers. In this work, the prior-reported straightforward and inexpensive strategy of upgrading CTPO using a combination of silica gel (as adsorbent) and petroleum ether (as the solvent) has been scaled up with minimal loss in mass of oil and improved physicochem. characteristics (e.g., lowered acid value, low sulfur content). The upgraded TPO (StTPO) was characterized extensively to better understand their chem. compositions, physicochem. properties, and combustion characteristics. StTPO was mixed with diesel in different volumetric proportions and the blends were studied for performance and emission characteristics in a single-cylinder engine. The use of biomass-derived Et levulinate (EL) as a fuel oxygenate improved the cold-flow properties of StTPO-diesel blends as well as lowered the exhaust emissions (e.g., lower NOx). A fuel blend consisting of 50% diesel, 40% StTPO, and 10% EL demonstrated the best fuel properties in the single-cylinder diesel engine.

RSC Advances published new progress about Adsorbents. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Product Details of C7H12O3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics