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The current research work focuses on the conventional bio-catalysed synthesis of amyl levulinate with immobilized Candida antarctica lipase B in the absence of a toxic solvent. The green catalyst and solvent free system offered considerable benefits like mild and gentle condition requirement, lesser-energy demand, easy down-streaming and reusability of the biocatalyst. The process parameters were examined, and the maximum conversion (73.2%) was obtained under the optimum condition of 50℃ temperature, 1:3 molar ratio of levulinic acid to amyl alcohol using 0.8% (w/v) biocatalyst at 250 rpm speed. The immobilized lipase was characterized by SEM, BET, XRD, FTIR and amyl levulinate was characterized by FTIR and GC-MS analysis. The enzyme lipase was effectively reused till 5 cycles for the formation of ester. The thermodynamic parameters (ΔH, ΔG, and ΔS) and energy of activation (Ea) were determined for the assessment of energy requirement. The activation energy was determined to be 48.42 kJ/mol. The research protocol strikes the development of biocatalytic synthetic route of amyl levulinate without using any toxic solvent, which may contribute to green chemistry approach.

This study is aimed at synthesizing amyl alcohol from Scenedesmus quadricauda third-generation microalgae biomass which is cultivated sustainably using reactor combinations and Ehrlich biosynthetic...

A microstructural analysis was performed to determine the presence of oxygen in a wire rod section of AISI 1008 steel with a surface mechanical failure produced during wire drawing. The failure zone was analyzed by comparison using three different attack reagents: alkaline sodium chromate (ASC), ASC with hydrogen peroxide and amyl alcohol, and a solution of nitric acid in ethyl alcohol. The reagents were applied in samples in the failure zone, showing different types of zones in regions with internal and superficial defects such as carbides, pores, cracks, deformation, and detachment zones, indicating the possible presence of oxygen. The areas identified were observed by means of an optical microscope and were correlated with the content of elements that were present in the region using a scanning electron microscope and a scattered X-ray energy spectrometer, which determined that the areas identified by chromate sodium correspond to regions with a high concentration of oxygen and slag-forming elements such as silicon, aluminum, and iron; this is associated with the presence of oxygen in the oxide form. It was also observed that the ASC and the modified ASC solution with hydrogen peroxide and amyl alcohol could identify areas with a high presence of oxides, while the nitric acid solution only identified the steel microstructure. The modified ASC solution is an alternative to identify the presence of chemical variants of oxygen because the conventional formulation is unstable and has a too short shelf life, and therefore, its application must be carried out at the time of preparation.

2-[(4-Carboxy methyl phenyl)azo]-4,5-di phenyl imidazole [4-CMePADPI] used for extraction chromium as CrO4−2 and Cr2O7−2 from aqueous solutions according to liquid ion exchange method after ion pair association formed, the procedure demonstrate concentration of HCl needed for formation liquid ion exchanger that give a high extraction efficiency with ligand is 0.2 M, for CrO4−2 and 0.3 M for extraction Cr2O7−2 in organic phase. Furthermore, the optimum pH for extraction the studied ions is pH = 10 for CrO4−2 and pH = 5 for Cr2O7−2 in aqueous phase. The shaking time necessary for extraction was 15 min for CrO4−2 and 10 min for Cr2O7−2. The optimal chromium concentration appears 40 μg/5ml and 30 μg/5ml for CrO4−2 and Cr2O7−2 respectively. The experiments also deduce that the favourable organic solvent for extraction is amyl alcohol without any effect for the polarity of organic solvents, as well as the results show that the anion exchange reaction was endothermic for both studied anions. In order to explain the mechanism of liquid ion exchange extraction and solubilization of the ion-association complex in the liquid–liquid extraction process, thermodynamic investigations have been carried out.

In this research, for the first time, the QuEChERS was combined with the dispersive liquid–liquid microextraction based on deep eutectic solvent (QuEChERS-DES-DLLME). The method was developed for efficient extraction, clean-up and preconcentration of acetamiprid (ACE) and imidacloprid (IMI), two commonly used pesticides, from pistachio samples before their determination by HPLC–UV. The pesticides were firstly extracted from pistachio samples and cleaned-up by QuEChERS, and then their supernatant was used as a dispersant in following DLLME in order to further purification and preconcentration. The extraction solvent used in DLLME was based on deep eutectic solvents (DESs). Preparation of hydrophobic DES was done by mixing amyl alcohol as hydrogen bond donor and trioctylmethylammonium chloride (TOMAC) as hydrogen bond acceptor. Different parameters that affect the efficiency of the two steps were evaluated and optimized. Under optimal conditions, the limit of detections was 1.5 and 3.0 μg kg−1 for ACE and IMI and the limit of quantification was 1.5 and 4.5 μg kg−1 for ACE and IMI, respectively. Calibration curves were linear in the range 5.0–500 μg kg−1 with correlation coefficients higher than 0.99. Preconcentration factor for ACE and IMI was 16 and 13, respectively. The intraday and interday precisions at concentration levels of 10 and 100 μg kg−1 were less than 7.0%. Finally, applicability of the suggested method was investigated through analysis of the analytes in some pistachio samples, and the obtained relative recoveries (95.6–99.4%) were acceptable. The good sensitivity and suitable purification in the analysis of the pistachio samples, as a complex food matrix, are obtained using the proposed method by combining the advantages of QuEChERS and DLLME.

This study aimed to investigate the effect of coatings on the quality of ripened dry-cured hams during long-term storage, especially the profile of volatile compounds. The coatings were made up of 33% palm oil, 16.5% water, 39.7% cassava starch, 6.8% corn starch, 1.6% mono- and diglycerides of fatty acids, 0.6% tert-butylhydroquinone (TBHQ), and 1.8% sodium carbonate. The results showed that the moisture content of the coated ham (48.93–49.59%) was higher than that of the noncoated ham (44.37%). The average peroxide value (POV) and b* value were lower in the coated hams than in the noncoated hams (5.52 and 8.99 meq/kg, respectively), and the sensory attributes of the coated hams had better overall acceptability scores. The changes in the contents of 39 volatile flavor compounds were evaluated through a multivariate statistical analysis, revealing that 20 identified compounds could be related to the decrease in fat pungent aroma, and most belonged to the long-chain benzene and carboxylic acid family. Meanwhile, 2-nonanone, nonanal, amyl alcohol, and 2-heptanone indicated that they could be used as markers to distinguish between the coated and noncoated groups. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-020-04579-z) contains supplementary material, which is available to authorized users.

Third-generation feedstocks and its constituent biofuels have shown promising results in the light of sustainable production and as a feasible fuel source for internal combustion (IC) engines. Hence, in this study, a third-generation microalgae feedstock (Scenedesmus quadricauda) biomass was cultivated sustainably using an in situ tubular photo bioreactor and raceway pond to synthesize quintet carbon chained amyl alcohol using Ehrlich biosynthetic pathway. On analyzing the synthesized amyl alcohol, a homogenous mixture of a 20% (vol/vol) amyl alcohol-diesel blend showed similarities with conventional diesel in their physio-chemical properties. This potential fuel source was analyzed though systematic experimentation at maximum throttle position condition in a light commercial vehicle compression ignition engine. The conducted experiments were directed by response surface methodology (RSM) coupled with central composite design (CCD) which delivered a set of influential and interactive responses on engine testing. At optimal operating condition, 0.7% rise in brake thermal efficiency (BTE) and an increased specific fuel consumption of 5.6% is reported due to the lower heating value of the biofuel. Furthermore, a 55.8% and 5.4% drop in smoke and carbon monoxide emissions is observed. However, oxides of nitrogen emission increases by 31.7% for biofuel operation as a tradeoff for the improved combustion characteristics achieved.

In this study, a headspace gas chromatography (HS-GC) method was carried out to determine the contents of acetaldehyde, methanol and fusel oils in distilled liquors and sakès from different countries. A DB-Wax column was adopted in HS-GC, which showed good linearity, high precision and accuracy and low LOQ and LOD on all the compounds. Results showed that distilled liquors contained higher levels of acetaldehyde with the values of 12.88–35.53 mg/L than sakès (0.83–29.13 mg/L). Methanol was only detected in a few distilled liquors with small amounts. Amyl alcohols, including isoamyl alcohol (2-methyl-1-butanol) and active amyl alcohol (3-methyl-1-butanol), isobutanol (2-methyl-1-propanol) and 1-propanol were the main fusel oils among the distilled liquors and sakès analyzed. Amyl alcohols contents were 2 to 4 times higher in Korean distilled liquors (203.01–428.66 mg/L) than that in Chinese distilled liquors (28.52–42.77 mg/L) and all the sakès (61.90–166.59 mg/L).

Mango plant (Mangifera indica L.) is a tropical fruit plant with high nutrition in the Anacardiaceae family. One of the several varieties of mango plants spread throughout Indonesia, namely mango golek. This study aims to obtain flavonoid isolates and find out the types of flavonoids in the leaves of mango golek. In this study, maceration was carried out to obtain ethanol extract, then followed by phytochemical tests, removal of chlorophyll using distilled water (1: 1), hydrolysis using 2N HCl, followed by liquid-liquid extraction using ethyl acetate and amyl alcohol. In the amyl alcohol fraction, flavonoid was separated using gravity column chromatography with a mixture of eluent n-butanol:n-hexane:methanol (4:2:1). Phytochemical tests showed positive results for alkaloids, saponins, tannins, quinones and flavonoids. UV-Vis spectrophotometer analysis provides absorption at a wavelength of 263 nm while FTIR analysis showed the presence of O-H, C=O, C-O-C aliphatic, and C-O alcohol groups. LC-MS/MS instrument analysis showed m/z of 300 which is the molecular mass of isoflavone compound.

The selectivity of 4-(Decyloxy) benzoic acid (DBA) liquid crystal in surface adsorption region (303.2-328.2 K) and thermodynamic region (423.2 - 433.2 K) was investigated by inverse gas chromatography at infinite dilution (IGC-ID). The selectivity parameters of the structural isomer series named butyl acetate, butyl alcohol, and amyl alcohol series were calculated for the DBA using IGC-ID technique. Additionally, the surface properties including dispersive surface energy (gS D), free energy (DGA S), enthalpy (DHA S), and acidity-basicity constants were calculated with net retention volumes obtained from IGC-ID experiment results. When the DHA S and DGA S are constants, DBA surface was found to be an acidic character (KD/KA @ 0.89).

This study aims to replace diesel with Prosopis Juliflora seed oil (JPO) in a compression ignition (CI) engine. The high viscosity of JPO promotes inferior performance and combustion. Brake thermal efficiency of JPO is 28.3%, which is less compared to 30.7% for diesel. This also leads to higher brakespecific energy consumption, HC, CO, and smoke emissions. JPO was converted to its biodiesel (Prosopis Juliflora methyl ester) (JPME) through the transesterification process. The physical properties were improved posttransesterification process. Brake thermal efficiency was improved to 29.3% for JPME. Higher NOx emission with reduced HC, CO, and smoke emissions was observed with JPME in comparison with JPO. The test engine employed for the investigations has a single-cylinder configuration with the maximum power of 5.2 kW enabled with water cooling. Furthermore, amyl alcohol was added with JPME in various proportions of 5%, 10%, 15%, and 20% by volume and experiments were conducted. The addition of amyl alcohol in the volume mentioned earlier has improved the thermal efficiency at higher loads; added to this NO and smoke emission were lowered simultaneously for all the loading conditions. Except with the 5% volume of amyl alcohol, HC and CO emissions have increased for all other volume compositions. JPME with 20% volume amyl alcohol exhibits the highest peak pressure and heat release rate. The brake thermal efficiency of JPME + A20 is on par with diesel. NO and smoke were reduced by 7% and 29%, respectively, for JPME + A20 in comparison with diesel. The study shows that the addition of 20% amyl alcohol with JPME has performance and emission characteristics similar to diesel. Further increase in amyl alcohol led to poor cold starting condition and may also lead to knocking. Hence, it was concluded to use only up to 20% of amyl alcohol to avoid any operational complications. WOS:000712768500001 Q2

The present work aims to develop a mathematical model, based on Gompertz equations and ANNs to predict the concentration of four solvent compounds (isobutanol, ethyl acetate, amyl alcohol and n-propanol) produced by the yeasts S. cerevisiae, Safale S04, using only the fermentation temperature as input data. A beer wort was made, daily samples were taken and analysed by GC-FID. The database was grouped into five datasets of fermentation at different setpoint temperatures (15.0, 16.5, 18.0, 19.0 and 21.0 °C). With these data, the Gompertz models were parameterized, and new virtual datasets were used to train the ANNs. The coefficient of determination (R2) and p-value were used to compare the results. The ANNs, trained with the virtual data generated with the Gompertz functions, were the models with the highest R2 values (0.939 to 0.996), showing that the proposed methodology constitutes a useful tool to improve the quality (flavour and aroma) of beers through temperature control.

The solubility of ropivacaine in fourteen pure solvents at 283.15 K to 323.15 K was determined via the gravimetric method and was well correlated with three thermodynamic models, including the Apelblat, λh, and NRTL models. Among all experimental solvents, the solubility of ropivacaine was found to be highest in pure THF and lowest in acetonitrile. In alcohol solvents, the maximum solubility was observed in amyl alcohol followed by 1-butanol, while the minimum value was observed in 1-propanol. The thermodynamic properties of mixing were calculated based on the NRTL equation, indicating that the mixing processes are spontaneous and entropy-driven. In addition, the crystal structure of ropivacaine was obtained and investigated by Hirshfeld surface analysis and molecular electrostatic potential surface analysis. In addition, the physicochemical properties of solvents, such as polarity, cohesive energy density and dielectric constant, were analyzed to explain the solid-liquid behavior of ropivacaine. Finally, a molecular dynamics simulation and radial distribution function analysis were performed. The results indicated that ropivacaine could interact with organic solvents via van der Waals interactions, electrostatic interactions, and hydrogen bonding.

Bacillus coagulans has been widely studied for its probiotic properties. Therefore, identifying a strain that can be used as an adjunct starter culture for yogurt production would have commercial value. In this study, 30 B. coagulans strains were isolated from vegetable samples from 11 provinces or autonomous regions in China, and their pan-genomic and phylogenetic characteristics were analyzed. Phylogenetic analysis categorized 30 strains into 4 different subphylotypes, including subtype I (11 isolates), subtype II (7 isolates), subtype III (11 isolates), and subtype IV (1 isolate). Four B. coagulans strains (B. coagulans-70, B. coagulans-78, B. coagulans-79, and B. coagulans-100) were randomly selected from each subphylotype of the phylogenetic tree as adjunct starter cultures. Compared with the other tested strains, B. coagulans-70 showed the highest count in yogurt at the end of the manufacturing period. Comparative genome analysis indicated that the different bacterial levels of B. coagulans strains in yogurt may be associated with the abundance of genes related to carbohydrate transport and metabolism (e.g., sucrose utilization). Finally, differences in texture and volatile flavor compound profiles were observed between the yogurt samples. Compared with the other groups, the addition of B. coagulans-70 exerted a positive effect on the appearance and texture of yogurt products. Volatile analysis showed increased quantities of 2-heptanone, 2-nonanone, amyl alcohol, and 2-hydroxy-3-pentanone in the B. coagulans-70 group compared with control yogurts. These results above combined with the results of a sensory evaluation indicated that B. coagulans-70 is the most suitable strain for further use in functional dairy product development.

In this study, experimental tests were carried out to improve the performance and emission characteristics of the diesel engine as amyl alcohol (pentanol), which is in the heavy alcohol class, obtained from the residual waste from etha-nol, which is produced as a by-product during sugar production from sugar beet. Tests were performed on naturally aspirated, air-cooled, four-stroke, single cyl-inder, direct injection, 6LD 400 Antor diesel engine at full load and engine speeds of 1400, 1700, 2000, 2300, 2600, 2900 and 3200 rpm. Pure diesel and fuel mixtures containing 5%, 10% and 20% amyl alcohol were used in the exper-iments. As a result of the experiments, while the power and torque values de-creased, the brake specific fuel consumption (BSFC) value increased as the ratio of amyl alcohol in the mixture increased compared to diesel fuel. In addition, the increase in amyl alcohol ratio in the mixture decreased hydrocarbon (HC), car-bon monoxide (CO), and smoke emissions, while increasing carbon dioxide (CO2) and nitrogen oxide (NOx) emissions. With 20% amyl alcohol ratio, an in-crease of 30.324% in BSFC value and a decrease of 13.745% and 10.258% in power and torque values were found as the average of all speeds, respectively. When evaluated in terms of emissions, with 20% amyl alcohol ratio, an average reduction of 44.565%, 42.832% and 27.330% was achieved in HC, CO, and smoke emissions, respectively, while NOx and CO2 emissions in-creased by 15.520% and 54.934%, respectively.

Lipase stability in organic solvent is crucial for its application in many biotechnological processes as biocatalyst. One way to improve lipase’s activity and stability in unusual reaction medium is its immobilization on inert supports. Here, lipases from different sources and immobilized through weak chemical interactions on hydrophobic and ionic supports had their transesterification ability dramatically dependent on the support and also on the solvent that had been used. The ethanolysis of sardine oil was carried out at the presence of cyclohexane and tert-amyl alcohol, in which Duolite A568-Thermomyces lanuginosa lipase derivative achieved 49% of ethyl esters production after 24 h in cyclohexane. The selectivity of immobilized lipases was also studied and, after 3 h of synthesis, the reaction with Duolite A568-Thermomyces lanuginosa derivative in cyclohexane produced 24% ethyl ester of eicosapentaenoic acid and 1.2% ethyl ester of docosahexaenoic acid, displaying a selectivity index of 20 times the ethyl ester of eicosapentaenoic acid. Different derivatives of Candida antarctica lipases fraction B (CALB) and phospholipase Lecitase® Ultra (Lecitase) were also investigated. Along these lines, a combination between these factors may be applied to improve the activity and selectivity of immobilized lipases, decreasing the total cost of the process., The authors thank the financial support from the São Paulo Research Foundation (FAPESP – grants 2012/09054-3 and 2013/00530-0), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES – grant number 3894/13-4).

The UV-Vis electronic absorption and excited-emission spectra of the 7-(Diethylamino) Coumarin were monitored experimentally in different solvents. The effect of solvent polarity on fluorescence quantum yield for C466 molecular structure is studied. Also, the critical micelle concentration (cmc) value calculated from the plot of the fluorescence intensity varies the concentrations of the cetrimonium bromide (CTAB) and sodium dodecyl sulfate (SDS). In addition to, the photostability of the studied molecular structure in different solvents such as acetone, methylisobutylketone and amyl alcohol in terms of half-life method (utilizing nitrogen laser 337.1 nm in pumping), as the number of pulses necessary to reduce the studied molecule intensity to 50% of its original value.The C466 molecular structurewas optimized using B3LYP/6-31G(d) level of theory. The computational electronic UV-Visabsorption spectra of the C466 compound, in gas and various solvents, were calculated using time dependent density functional theory (TDDFT) at B3LYP/ 6-311G++(2d, 2p) level. The obtained theoretical results were compared to experimental ones. The results show that, the computational optical properties of the studied molecular structureis in agreement with experimental results.

The effects of using blends of unleaded gasoline and refined fusel oil on engine performance and exhaust emissions were analyzed. Prior to the experiment, the fusel oil, which is the final waste product of the sugar factory, was developed to have the chemical properties that can be used in internal combustion engines by removing water and gum contained therein. A four-stroke, single-cylinder, spark-ignition engine was used for the experiments. The tests were conducted at a fixed speed and under different loads. The test fuels were blended with fusel oil contents of 5%, 15%, and 30%. Under each load, the engine’s performance and emissions were measured. Throughout the experiments, it was observed that engine torque and fuel consumption increased as the amount of fusel oil in the blend increased. Nitrogen oxide (NOx), carbon monoxide (CO), and hydrocarbon (HC) emissions were reduced as the amount of fusel oil in the blends increased.

Apigenin is one of the flavonoid compounds contained in celery ( Apium graveolens L.) and has been used for the treatment of various diseases. This study aims were to ensure the validity and accuracy of analytical method for apigenin assay in celery extract using UV-Vis spectrophotometry. The flavonoids test of celery extract give a positive result which produces a yellow color that can be drawn by amyl alcohol. The result of TLC test using a mobile phase of chloroform and methanol (9.5 : 0.5) produced R f value of 0.75. Validation of analytical methods were sensitivity, linearity, limit of detection as well as limit of quantification, accuracy, and precision. Validation of analytical methods showed that sensitivity results as represented by molar extinction (e) was 77004.35 M -1 cm -1 . Linearity from calibration curve at concentration of 2, 4, 6, 8, and 10 mgL -1 resulted an equation of y = 0.074 x – 0.0011 with coefficient correlation (r) of 0.9996. The limit of detection and limit of quantification were 2.99 mgL -1 and 9.92 mgL -1 respectively with recovery percentage of 97.59% and the coefficient variation values were 1.53%; 2.43% and 1.68%. The average contents of apigenin in the celery extract were of 3.74 ± 0.09%.

Porcine adulteration in meatball samples were analyzed using real-time polymerase chain reaction (RT-PCR), based on the ND5 primer obtained by previous study. This work consisted of three stages which were annealing temperature optimization, method validation, and application. DNA template was extracted using phenol-CIAA (chloroform-iso amyl alcohol) method. The optimum annealing temperature for ND5 primers (forward primer 5'-CATTCGCCTCACTCACATTAACC-3' and reverse primer 5'-AAGAGAGAGTTCTACGGTCTGTAG-3') was 58.0 °C, obtained after testing annealing at 50.5 to 59.5 °C gradient temperature with 5 °C interval. Melting curve analysis was done at 65.0 to 95.0 °C, with increasing temperature for 0.5 °C per 2 sec. Method was validated for its specificity, precision and limit of detection. RT-PCR method with ND5 primers produced 227 bp DNA fragment with 78.50 °C Tm value. From eight commercial meatball samples, one was detected containing porcine. The methods showed high specificity and precision, with experimentally determined limits for porcine were no less than 1%.

Bronsted acidic ionic liquid, N -methyl-2-pyrrolidonium methyl sulfonate ([NMP] + CH 3 SO 3 − ) immobilized on MIL-101(Cr) was fabricated by simple impregnation method with a good combination of MIL-101(Cr) and IL species. The worthiness of IL/MIL-101(Cr), as a Bronsted acid catalyst, has been examined for the esterification of acetic acid with amyl alcohol and Friedel–Crafts acylation of anisole. Our findings demonstrated that IL/MIL-101(Cr) catalyst exhibited distinct catalytic activity with respect to the other catalysts towards the esterification reaction and Friedel–Crafts acylation of anisole. The Bronsted acidic catalysts loaded on MIL-101(Cr) as a new category of porous materials are probably auspicious heterogeneous catalysts for acid-catalyzed to replace the use of traditional homogeneous catalysts. Furthermore, the catalyst can be easily removed from the reactions mixtures and reuse for posterior reactions, more than six times without any considerable decay in catalytic performance.

The etherification of glycerol with isoamylenes has been studied employing twelve catalytic ion-exchange resins in order to establish the basis for a novel green process coming from this renewable source. Two compositionally different experimental approaches to transform glycerol in biodiesel additives were considered i.e. using glycerol (G), tert -amyl alcohol (TAA) and/or isoamylenes (IA) in variable molar ratios. Reactions were carried out in a stainless steel batch minireactor at temperatures between 313 and 348 K, autogenous pressure to 1.5 MPa and 1–24 h reaction time. The influence of initial molar ratio of reactants, temperature, pressure, reaction time and the catalyst employed were evaluated to optimise the process and attain the maximum conversion of glycerol. Optimization of mixtures of glycerol with TAA resulted in maximum glycerol conversion attaining 51% whilst greater glycerol conversions close to 70% were achieved using mixtures of glycerol/isoamylenes/ tert -amyl alcohol.

Fusel oils (FOs) are higher alcohols (including propanol, isobutanol, isoamylol, and active amyl alcohol), which affect the aroma profiles and flavor profiles of wine. A novel method for determination of FOs in lychee wine was developed using headspace gas chromatography (HS-GC). Results showed that 12% standard curve (SC) can be used to determinate the FOs of low alcoholic beverages, yet 40% SC can be used for high alcoholic beverages (e.g., brandy). Optimization of the parameters of equilibrium temperature at 50 °C was maintained for 30 min. The stabilized gas-liquid phase ratio of 3:1 for further research had no significant differences with others, which is caused by the distribution coefficient of K ≫ 100. The addition of sodium chloride (NaCl) decreased the partition coefficient of FOs markedly, and an inverse situation was observed for the extraction of FOs saturating at 1.25 g NaCl in 5 mL LW. Relative standard deviations (RSD) of reproducibility tests were in the range of 1.03–4.91%. Meanwhile, the mean recoveries of low, middle, and high concentration levels were 100.94, 103.2, and 96.74%, respectively. HS-GC was a stabilized, concise, and efficient method compared with the International Organization of Vine and Wine (OIV) method of OIV-MA-BS-14. These findings provide a foundation to determine higher alcohols of alcoholic beverages.

Relative permittivities and refractive indices were measured for the several polar binary systems containing straight-chain primary diols and primary pentanol isomers over the whole composition range at 298.15 K and atmospheric pressure. The pentanol isomers were 1-pentanol (amyl alcohol), 3-methyl-1-butanol (isoamyl alcohol), and 2-methyl-1-butanol (active amyl alcohol). The chosen diols were 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. The excess parameters, i.e. excess permittivity, excess Helmholtz energy and excess Kirkwood correlation factor, were determined. The Reis-Ιglesias formulation was used to obtain information on the molecular interactions and structure in these binary systems.

Herein, we report the purification and characterization of an alkaline protease from the alkaliphilic Salipaludibacillus agaradhaerens (formerly Bacillus agaradhaerens) strain AK-R, which was previously isolated from Egyptian soda lakes. The purification procedures resulted in enzyme purification up to 13.3-fold, with a recovery yield of 16.3% and a specific activity of 3488 U/mg protein. AK-R protease was a monomeric protein with an estimated molecular weight of 33.0 kDa. The optimum pH and temperature for AK-R protease were pH 10 and 60 °C, respectively. The enzyme thermostability was significantly enhanced in the presence of CaCl(2) by approximately 1.3-fold. Moreover, under optimal conditions, the K(m) and V(max) values of the enzyme were 2.63 mg/ml and 4166.7 U/mg, respectively. PMSF caused complete inhibition of the enzyme activity, suggesting that AK-R belongs to the serine protease family. In addition, the enzyme was completely inhibited by EDTA, revealing the requirement of metal ions for AK-R protease activity; hence, it can be classified as a metalloprotease. AK-R protease is a mostly thiol-independent enzyme, since thiol reductants such as β-mercaptoethanol and dithiothreitol had no effect on the enzyme activity. AK-R protease exhibited high stability in several organic solvents, including butanol, amyl alcohol, dimethyl ether, toluene, diethyl ether and methanol. Moreover, AK-R protease showed significant stability to a variety of surfactants and commercial detergents. The features and properties of AK-R alkaline protease are favourable and suggest its potential applications in various industries, particularly in the laundry detergent industry. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-019-1928-9) contains supplementary material, which is available to authorized users.

The Co-based catalysts were prepared with different cobalt acetate solutions. Effects of pH value were studied deeply on Fischer–Tropsch synthesis (FTS) through a semi-batch reactor. Among all impregnation solutions (water, butanol, amyl alcohol, acetic acid, nitric acid and ammonium nitrate), the catalyst prepared by NH4NO3 solution showed the highest catalytic activity due to its small particle size and high reduction degree. However, the catalyst with the smallest particle size derived from water as impregnation solution exhibited low activity as well as high methane selectivity since it was difficult to be reduced and inactive in FTS. According to FT-IR spectra results, the low intensity of absorbed CO on the catalyst prepared from water solution resulted in low FTS activity. Whereas, the high activity of catalysts prepared from NH4NO3 solution could be explained by the high intensity of absorbed CO on the catalysts. The cobalt species on the catalysts prepared under lower pH conditions exhibited smaller particle size distribution as well as lower CO conversion than those prepared at higher pH value.

This paper proposes a method to perform rapid and sensitive graphite furnace atomic absorption spectrometry (GFAAS) determination of Cr(VI) in vinegar samples without wet digestion. Taking into account low levels of Cr(VI) and the presence of several concomitants in the sample matrix, the proposed method uses single-phase liquid-liquid extraction (SPLLE). The method is automated, employing a flow-batch analyzer (FBA) which uses a mixing chamber designed to emulate a separation funnel promoting the formation/break of the single-phase solution, reaction and extraction. The Cr(VI) extraction procedure was performed by proportioned mixing of the vinegar sample (aqueous phase), amyl alcohol (organic phase), and ethanol (consolute) to form a single-phase solution. The chelating reagent sodium diethyldithiocarbamate (DDTC) dissolved in the consolute reacts rapidly with Cr(VI), in the single phase to produce a stable Cr-DDTC complex. The single-phase break step is performed by adding an excess of Britton-Robinson buffer, and then the organic phase enriched with Cr(VI) was analyzed by GFAAS. Factors such as extraction steps, single-phase composition, pH, chelating agent concentration, and flow-batch parameters were optimized. The FBA-SPLLE-GFAAS was evaluated in vinegar samples showing satisfactory analytical features in terms of limit of quantification (0.86 μg L −1 ), precision (RSD

This study investigates how fusel oil affect the thermal performance of a two-phase closed thermosyphon (TPCT) at various states of operation. The present study experimentally demonstrated the effect of using fusel oil comprised of various types of alcohols (1.1 % ethyl alcohol, 74.7 % amyl alcohol, 11.3 % isobutyl alcohol, 4.9 % butyl alcohol and 3.8 % propyl alcohol and 4 % water) in varying ratios on improving the performance of the TPCT. Fusel oil has been obtained from fermentation plants as a by product. A straight copper tube with an inner diameter of 13 mm, outer diameter of 15 mm and length of 1 m was used as the TPCT. The fusel oil was filled up 33.3 % (44.2 ml) of the volume of the TPCT. Three heating power levels (200, 300 and 400 W) were used in the experiments with three different flow rates of cooling water (5, 7.5 and 10 g/s) used in the condenser for cooling the system. An increase of 17.64 % was achieved in efficiency of TPCT when fusel oil was used to replace deionized water at a heat load of 200 W and with a cooling water flow rate of 10 g/s.

A microemulsion with hydrochloric acid solution as the polar phase, n-heptane as the continuous phase, [C14-4-C14im]Br2 as an ionic-liquid-type imidazolium gemini surfactant and extractant, and n-amyl alcohol as cosurfactant was studied on Au(III) extraction. Compared to its corresponding monomer [C14-mim]Br-based microemulsion for Au(III) extraction, the [C14-4-C14im]Br2-based microemulsion system showed excellent extractability of Au(III). The anion-exchange mechanism of Au(III) extraction was confirmed by the slope method and spectrum analysis (UV–vis, FT-IR, and 1H NMR). Main influence factors such as phase ratio, extraction equilibrium time, amyl alcohol volume fraction, and the concentration of ionic liquid on the extraction efficiency (E%) were explored. Moreover, [C14-4-C14im]Br2-based water-in-oil microemulsion had high selectivity over a multimetal ion solution (Co (II), Cu(II), Fe(III), Ni(II), Sn(IV), and Al(III)). Therefore, it is indicated that [C14-4-C14im]Br2-based microemulsion provides a...