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In this work, the results of the experimental study of the chemical equilibrium in both homogeneous and heterogeneous areas for the system acetic acid–n-amyl alcohol–n-amyl acetate–water at 323.15 K and atmospheric pressure are presented. The chemical equilibrium compositions and compositions of coexisting liquid phases were determined by gas chromatography. The obtained compositions were plotted in a composition tetrahedron for better clarity. The tie-lines of the heterogeneous chemical equilibrium were presented in transformed variables (the α-variables). The peculiarities of the surface of the chemical equilibrium are discussed. The obtained data are compared with the literature information at 318.15 K. The value of the thermodynamic constant of the chemical equilibrium was estimated using three approaches: an empirical equation, the UNIFAC model, and the quantum chemical calculation.

The liquid phase esterification of lactic acid with n-amyl alcohol over an acidic cationic exchange resin such as Indion 180, Amberlyst-15 and Seralite WRC-50 was carried out on a laboratory scale. The activity and performance of Indion 180, Amberlyst-15, and Seralite WRC-50 were evaluated. Kinetic experiments were conducted in a batch reactor in the reaction temperature range from 333 to 363 K. The Eley–Rideal and Langmuir–Hinshelwood model was used to correlate the kinetic data and the estimation of kinetic parameters. The UNIFAC group contribution method was applied to study the nonideality in the reaction. Theoretically, mass transfer limitations were calculated from the reaction kinetics data. The activation energy and enthalpy of esterification reaction were found to be 43.71 ± 0.56 and 51.42 ± 0.64 kJ/mol. The response surface methodology was employed for statistical model development and optimization in the temperature range from 333 to 363 K, initial molar ratio 1 to 4, and catalyst loading from 2 to 8%. The maximum optimized conversion (53.89%) of lactic acid was found at temperature 357 K, molar ratio of 2.82, and catalyst loading of 6.17%. The predicted conversion (53.89%) by quadratic response surface model was good agreement with the experimental conversion (54.68 ± 1.13).

This study reports significant energy savings of combined reaction and distillation in a single reactive dividing wall column (RDWC) for the concurrent production of pure n-amyl and n-hexyl esters, which are the stable node (SN) in each phase diagram of the quaternary reaction system. The continuous removal of the byproduct, water, from the unstable node (UN) azeotrope by L-L decantation drives the two esterifications in the forward direction and enables the production of the pure ester products. A vapor recompression heat pump (VRHP) is introduced to the RDWC and the annual operating cost is reduced to 62.5% of the case without the VRHP. Implementing the multiple reactions with V-L-L separation in a single RDWC and its heat integration through the VRHP may provide chemical industries with enhanced economic feasibility.

Nano-TiO2 powder was synthesized by the continous-orderly-controlled-explosive nucleation method [1]. The experiment has effectively degenerated the n-amyl alcohol gas, and investigated its influencing factor by using the Nano-TiO2 photocatalytic activity[2]. When the initial density of the n-amyl alcohol gas is 1714.7mg/m3, the TiO2 calcination temperature is 450℃, the dosage of catalyst is 9.98g. The experiment reacts 40 minutes later, degeneration rate of the n-amyl alcohol achieves above 98%, and the degeneration rate increases constantly with the extension of reaction time. This study provides a solution for the environment pollution problem which the n-amyl alcohol produces.

Biofuels are considered as one of the best viable and inexhaustible alternatives to conventional diesel fuel. Alcohols have become very important and popular in the present scenario due to their peculiar fuel properties and production nature. This study examines the effect of n-amyl alcohol and exhaust gas recirculation of 10% and 20% on various engine characteristics of common rail direct injection (CRDI) compression ignition engine. The proportion of n-amyl alcohol varies from 5% to 25% in 5% step (by volume). The obtained results show that diesel/n-amyl alcohol blends decrease the mean gas temperature and cylinder pressure, which is 1.88% and 4.25% less at 75% load for n-amyl alcohol (25%) with conventional diesel fuel. The duration of combustion has shown a hike of 4.66 °CA for 25% n-amyl alcohol (at 75% load) compared to conventional diesel fuel. However, the cumulative heat release rate improved by 12.95% higher for 25% n-amyl alcohol at 75% load due to the extended delay in ignition. While n-amyl alcohol was used, the emission of nitrogen oxide emissions decreased considerably. However, the hydrocarbon (HC) (7–9%) and carbon monoxide (CO) (6–8%) emissions are increased due to inferior fuel properties like high latent heat evaporation of n-amyl alcohol. Compared with other blends, n-amyl alcohol (5%) produced results comparable to conventional diesel fuel, which is 3.6% higher in BSFC, 2.37% higher BTE, and 33.33% higher CO emissions 18.18% more in HC emission, and 17.55% less NOx emission. Without further modification, we can use 25% n-amyl alcohol in the combustion ignition engines. From this evidence, we can summarize that n-amyl alcohol is a biofuel that is both renewable and sustainable, and also it considerably reduces harmful nitrogen oxide emissions. The performance, if needed, can be improved by changing the parameters of the engine.

Modified palygorskite with 3-aminopropyltriethoxysilane (KH550) was used as the carrier to immobilize a 12-heteropolyacid of molybdenum and tungsten. The prepared catalyst was characterized by FT-IR, XRD, XPS, BET and TG. The kinetic behavior of heterogeneous esterification of acetic acid with n-amyl alcohol over the catalyst was investigated. The nonideality of the liquid phase was considered by using activities instead of molar fractions. The activity coefficients have been calculated by using the group contribution method UNIFAC. The experimental results showed that the reaction is controlled by chemical steps rather than external and internal mass transfer steps. Experimental data fitted well to the pseudo-homogeneous (PH) model. The temperature dependency of the equilibrium constant and the reaction rate constant were found. It indicated that the heat of reaction is 7.33 kJ mol−1. The new rate equation gave a good fit to the data and was able to describe the behavior of the system.

Kinetics of heterogeneous catalysed esterification of propionic acid with n-amyl alcohol was studied with a microporous cation-exchange resin catalyst, Dowex 50Wx4, in a stirred batch reactor to synthesise amyl propionate. Effects of various parameters such as speed of agitation, catalyst loading, and reaction temperature on reaction rate were investigated. The equilibrium conversion of propionic acid increased with in catalyst loading and reaction temperature. Stirrer speed had virtually no effect on the reaction rate under the experimental conditions. The apparent activation energy was found to be 43.167 kJmol−1for the formation of amyl propionate and the equilibrium constant, which is independent of temperature ranging from 318 to 348 K, was found to be 4.05. It was also observed that the initial reaction rate decreased with water concentrations and increased with that of acid and increased with that of alcohol linearly. The reaction was found to occur between an adsorbed acid molecule and a molecule of alcohol in the bulk and it was concluded that the reaction mechanism can be represented by Eley-Rideal model.

ABSTRACTIn the work presented here, l,2-dihidroxy-4-oxadodecane (DHD) was synthesized and used for the solvent extraction of boron. DHD was prepared from glycidol and octanol by thermal epoxide ring opening reaction without using acid or base catalyst. The structure of this new extracting reagent was identified according to its spectroscopic data i.e. 13C NMR, 1H NMR and elemental analysis results. The fixed standard solution of boron (as borax) of 10−4M was extracted with different volume ratios of DHD and n-amyl alcohol (AA) at different equilibrium pH values. The best extraction result was obtained at high pH values with a mixture of equal volumes of DHD and n-amyl alcohol. The different equilibrium pH values were plotted against the extraction yields (%R) and the pH0·5value was determined by using this graph. The extraction of boron from aqueous solutions with equal volumes of DHD and various solvents were studied and it was found that petroluem ether, n-amyl alcohol and diisopropyl ether are convinient solvents for boron extraction. Stripping of boron loaded organic phase was achieved with H2SO4aqueous solutions. The effect of stripping as a function of H2SO4cocentration was also studied

The title compound [(μ–O){Fe(Cl)(bpy)2}2]Cl2· 0.7 C5H11OH (bpy = 2,2′-bipyridyl) crystallizes in orthorhombic system with the space group Pnna(No. 52). Crystal data: a= 16.892(2) Å, b= 17.656(2) Å, c= 16.552(2) Å, V= 4936.6(12) Å3, Z= 4, dcalc= 1.286 g · cm−3. The full-matrix least-squares on F2was refined for 1804 reflections with (I> 2σ(I)) and 213 parameters to R1 = 0.0912.

The solubility of d-psicose in 15 pure solvents, including methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, n-amyl alcohol, n-hexyl alcohol, acetonitrile, ethyl formate, methyl acetate, ethyl acetate, butyl acetate, acetone, and 2-butanone, was determined by the gravimetric method in the temperature range of 283.15–323.15 K. The solubility of d-psicose was the highest in methanol and the lowest in acetonitrile. At the temperature of 298.15 K, the solubility of d-psicose in alcohol solvents is as follows: methanol > ethanol > isopropanol > n-propanol >2- butanol > n-butanol > n-amyl alcohol > n-hexyl alcohol. The solubility in the esters is as follows: ethyl acetate > ethyl formate > methyl acetate > butyl acetate. The solubility in ketone solvents is as follows: acetone >2-butanone. The modified Apelblat model, λhmodel, nonrandom two-liquid (NRTL) model, and Van’t Hoff model were used to analyze the solubility data of d-psicose in 15 pure solvents. The solvent effect of d-psicose in the measured solvent was investigated by KAT-LSER model. The results show that hydrogen bond acidity and Hildebrand solubility parameters have important effects on the solubility of d-psicose. The thermodynamic properties of the mixing process were calculated according to the NRTL equation, which shows that the mixing process is spontaneous and entropy-driven.

n-Amyl alcohol was examined as a source for the synthesis of the 3-hydroxyvalerate (3HV) unit of the biopolyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)), by Alcaligenes sp., Pseudomonas sp. and several methylotrophic bacteria. A. eutrophus and Ps. lemoignei synthesized P(3HB-co-3HV) from glucose and n-amyl alcohol under nitrogen-deficient conditions. Many of methylotrophic bacteria grown on methanol synthesized the copolyester from methanol and n-amyl alcohol under nitrogen-deficient conditions. The content and composition of the polyester varied from strain to strain. Paracoccus denitrificans differed from all others in having a higher content of 3-hydroxyvalerate units in the copolyester synthesized.

The equilibrium solubility of 5,6-dimethoxy-1-indanone in 15 commonly used solvents, including methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butanol, n-amyl alcohol, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, acetone, and 2-butanone, was investigated in the temperature range of 283.15–323.15 K by a gravimetric method under atmospheric pressure (0.1 MPa). With the capacity of dissolving 5,6-dimethoxy-1-indanone, esters and ketones are higher than alcohols. The order is as follows: 2-butanone > acetone > ethyl acetate > n-propyl acetate > isopropyl acetate > butyl acetate > n-amyl alcohol > isobutyl alcohol > sec-butanol > n-butanol > methanol > n-propanol > ethanol > isopropyl alcohol. It was found that the dissolution property of 5,6-dimethoxy-1-indanone was related to the solvent properties including solvent polarity, hydrogen-bond donor propensity, and cohesive energy density. Furthermore, four thermodynamic models consisting of the modified Apelblat equation, van’t Hoff equation, λhequation, and NRTL model were used to correlate experimental data and all showed good fitting accuracy.

In this paper, the solubility of terbinafine hydrochloride in 13 mono-solvents was measured in the temperature range from 283.15 K to 323.15 K at ambient pressure with the assistance of a laser-based dynamic solubility-monitoring device. It was concluded that the solubility of terbinafine hydrochloride in these mono-solvents increases with rising temperature. At 323.15 K, the molar solubility shows the following order: cyclohexanol (7.739 × 10–2) > n-propyl alcohol (7.351 × 10–2) > n-amyl alcohol (6.967 × 10–2) > iso-butanol (6.932 × 10–2) > n-butanol (6.850 × 10–2) ≈ ethanol (6.778 × 10–2) > isoamyl alcohol (4.926 × 10–2) >1-hexanol (4.689 × 10–2) > dimethyl sulfoxide (4.010 × 10–2) > sec-butanol (2.878 × 10–2) > isopropyl alcohol (2.452 × 10–2) > isooctyl alcohol (2.211 × 10–2) > acetonitrile (0.532 × 10–2). Subsequently, the relationship between the solubility of terbinafine hydrochloride and temperature was correlated by six models (Apelblat, van’t Hoff, λh, Wilson, NRTL, and Jouyban models), and the mixing thermodynamic properties of the solutions were evaluated with the solubility and the parameters simulated by the Wilson model. In addition, the solvent effect on the solubility of terbinafine hydrochloride was discussed based on the Kamlet–Abboud–Taft linear solvation energy relationships.

In this paper, the solubility of menadiol diacetate in nine alcohols (methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, n-amyl alcohol, i-amyl alcohol, and cyclohexanol) and five n-alkyl acetates (methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, and amyl acetate) was experimentally measured with the aid of a laser dynamic device at temperatures from 283.15 to 323.15 K. The solubility of menadiol diacetate as a function of temperature was regressed in terms of three semiempirical solubility models (Apelblat, van’t Hoff, and λh), two activity coefficient solubility models (Wilson and NRTL), and the Jouyban model. The thermodynamic mixing properties (mixing Gibbs energy, entropy, and enthalpy) of the solutions were estimated in terms of the measured solubility data and the regressed parameters of the Wilson model.

The purpose of this study is to examine the reactivity-controlled compression ignition (RCCI) engine combustion characteristics using jatropha oil blended with diesel as the high reactivity and n-amyl alcohol as low reactivity fuel in various proportions by volume. Response surface methodology is adopted to forecast the operating parameters such as fuel injection timing (FIT), fuel injection pressure (FIP), and engine load. This ideal model is used to obtain maximum combustion pressure and reduce the emission of unburnt hydrocarbon (HC) and oxides of nitrogen (NOx) for different fuel blends. For an RCCI engine fueled with B20/1-pentanol fuel, the impact of various factors such as engine load, FIT, and FIP are analyzed based on an L20 orthogonal array. With the help of results obtained from experiments, various models were developed and validated. The ideal engine parameters found out were 71% of engine load, FIP of 400 bar, and 27 0bTDC, and under this configuration, the maximum cylinder pressure is achieved. The ternary fuel develops higher maximum pressures of combustion than that of pure diesel at higher loading conditions, pressures of fuel injection, and advanced injection timings. At lower loading conditions, fuel injection pressures and ignition delay are noticed, whereas peak pressure decreases. Also, Analysis of variance (ANOVA), a statistically valid test, is used to develop a regression model, and the test results indicate that the regression model is appropriate for the following R2 values obtained.

The quartz crystal microbalance (QCM) modified by chitosan/α-pinene, prepared by spin-coating technique has been successfully developed with molecular imprinting polymer (MIP) concept. To remove the template, we carried out two treatments namely heating and vacuum in a desiccator. To find out selectivity of the sensor, the QCM modified with polymer chitosan has been tested with another analyte such as acetone, ethanol, N-amyl alcohol, iso-amyl alcohol. The result shows that chitosan/α-pinene coated QCM sensor can provide a good response as good as sensitivity. The best QCM at heating treatment in a furnace with the decline of frequency is 32 Hz, then the QCM vacuum pumping treatment with decline frequency is 27 Hz.

One issue with batch fermentation is that product inhibition causes low yields and ethanol productivity. The objective of this study was to increase the yield and ethanol productivity via continuous fermentation in a packed bed bioreactor with both an integrated extraction process and recycling of the raffinate into the fermenter. Molasses was used as the feedstock, and the immobilized cells were supported by ĸ-carrageenan. This process used n-amyl alcohol, 1-octanol, and 1-dodecanol as solvents. The yield and ethanol productivity increased from 8.79% to 20.03% and 34.54 g/L·h to 118.16 g/L·h for experiments using n-amyl alcohol, 9.05% to 12.67% and 35.59 g/L·h to 74.71 g/L·h, for 1-dodecanol, 8.89% to 13.45% and 34.93 g/L·h to 84.62 g/L·h, for1-octanol by increasing recycle ratio from 0 to 0.5. Based on these results, n-amyl alcohol was the best solvent for the extractive fermentation process.

The n-amyl acetate synthesis from the esterification reaction of acetic acid and n-amyl alcohol in a pilot plant catalytic distillation column with a decanter was evaluated. A novel catalytic packing, seepage catalytic packing internal (SCPI), is applied in this study. Catalytic distillation experiments using different feed molar ratios and feed modes at different column pressures were performed to validate an equilibrium stage model developed to investigate the influence of operation parameters on the performance of the catalytic distillation process. The results from experimental runs and simulations clearly indicate that it is important to the performance of catalytic distillation process to adjust the composition and temperature profiles along the reaction zone. The studies also showed that the integration of a reactive distillation column with a decanter is considered a potential candidate to produce amyl acetate. With proper operation parameters (operating pressure of 20–22 kPa and mixed feeding mode) and column configuration (16–18 theoretical stages of reaction zone), the product purity in the bottom stream could be increased to 99.3 wt % and less than 0.2 mg KOH/g acid value, meanwhile the conversion of amyl alcohol could reach more than 95%. The research achievements can be applied to facilitate industrial application of SCPI and used for prospective optimization studies.

ABSTRACTAn effective alternative for the non-renewable fuel is vegetable oil. The major properties of vegetable oil that oppose the above statement is its high viscosity and low volatility, which could lead to several problems in compression ignition engines. So, the viable method to make it suitable for using in Compression Ignition engine is converting the same to biodiesel, that is, vegetable oil esters using the process of transesterification. During this study, the emission characteristics of a direct injection diesel engine that is fuelled with a blend of mustard oil biodiesel and n-amyl alcohol are compared. The test has been performed at a steady-state condition in a single-cylinder direct injection diesel engine at a constant speed of 1500 rpm. The test results revealed a significant reduction in the emissions like smoke and oxides of nitrogen.

Recoveries of 14C-labeled morphine from aqueous solutions containing 1 to 500 ng. of drug (containing no ammonium ions) by extraction with three volumes of ethylene chloride containing 10, 20, or 30% of n-amyl alcohol were 82.9, 91, and 96%, respectively. Dihydromorphine was 79.1% extracted by ethylene chloride containing 30% n-amyl alcohol, and codeine, 97%, with all the above mentioned solvent mixtures. Complete hydrolysis of conjugated metabolites of morphine, codeine, or dihydromorphine was achieved by autoclaving samples in a portable autoclave at 18-20 lb. pressure for 2 hr. in a solution of 1.1 NHCl, or for 1 hr. in 2.2 NHCl, or 0.5 hr. in 3.3 NHCl. The conjugated metabolites were also completely hydrolyzed by treatment in a steam-jacketed autoclave at 20 lb. pressure for 0.5 hr. in 2.2 NHCl or 1 hr. in 1.1 NHCl. A procedure is described for the estimation of codeine and its metabolites, including morphine, in the same samples.

Summary: Contraversal results about the behaviour of Fe-EDDHA in soils is thought to be due to the indirect methods used for determining the iron chelate compound in soils. The purpose of this investigation is to develop a method for isolation of Fe-EDDHA from soil extracts inorder to be determined separatly. A 4% solution of tetra-n-heptylammonium iodide in ethyl alcohol was found effective in forming a water-insoluble but n-amyl alcohol-soluble compound of Fe-EDDHA. It was found that the absorption spectra of the iron chelate extracted with n-amyl alcohol has an absorption maximum of 480 m corresponding to that of iron chelate of the aqueous solution. The extracted iron chelate adhers to Beer's low in the range of 0 to 120 ppm of Fe-EDDHA. The method of Fe-EDDHA extraction was found to be selective for the isolation of the iron chelate from other soluble compounds. The procedure was also found to be highly efficient in quantitative isolation of Fe-EDDHA, with percent recovery ranging from 97–100. The incubation study of Fe-EDDHA in different soils indicated that the loss of Fe-EDDHA is associated with the organic matter content in the soil. The colorimetric determination of the total metal chelates did not indicate any replacement of other metals for the chelated iron in the soil.

Liquid–liquid equilibrium study was performed on the eight ternary systems containing binary azeotrope mixtures (n-heptane + n-amyl alcohol or isoamyl alcohol) and deep eutectic solvents at 298.15 K and 101 kPa. In order to evaluate the influence of structure of the constituent components on the phase equilibria, the ternary systems were systematically analyzed. In this research, four choline chloride based deep eutectic solvents (ChCl-DESs) were synthesized for separation of the amyl alcohols from a hydrocarbon (n-heptane). The prepared DESs were choline chloride + ethylene glycol (DES1; 1:2 mol ratio), choline chloride + propylene glycol (DES2; 1:3 mol ratio), choline chloride + 1,4-butylene glycol (DES3; 1:4 mol ratio), and choline chloride + diethylene glycol (DES4; 1:4 mol ratio). The Othmer–Tobias equation was applied to check the reliability of the tie-line compositions. The measured equilibrium data were correlated by the NRTL model, and the binary interaction parameters were determined. The consistency of the model parameters was validated by topological analysis connected to the Gibbs tangent principle. Distribution coefficients and separation factors were obtained from the tie-line data in order to evaluate the capacity of the studied deep eutectic solvents. The obtained solute distribution coefficients were found to be almost similar for all the studied ternary systems.

Yeast microbodies isolated from methanol-grown cells of Kloeckera sp. No. 2201 were immobilized by two types of entrapping techniques: photocrosslinking of liquid oligomers of suitable photosensitive resins and crosslinking of albumin molecules with glutaraldehyde. The apparent activities of catalase, alcohol oxidase, and D-amino acid oxidase in the gel-entrapped microbodies were 40–50, 70–80, and ca. 50% respectively as compared with those in the free microbodies. Alcohol oxidase in the immobilized microbodies, similarly to that in free ones, oxidized methanol, ethanol, n-propanol, n-butanol, n-amyl alcohol, and benzyl alcohol. Some properties of catalase and alcohol oxidase in the microbodies immobilized by the above-mentioned techniques were studied in comparison with those of the enzymes in the free microbodies.

Extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) experiments have been carried out to probe the Zn2+ and Rb+ environment in perfluorinated ionomers. The cation environment has been determined for these ionomers in their dry, hydrated and n-amyl alcohol swollen state. It was found that a well ordered, crystalline-like nearest-neighbor oxygen shell predominates in the zinc neutralized perfluorinated ionomers. Unlike the zinc ionomers, the Rb+ neutralized ionomers show no discernible peaks in the radial structure function indicating that the rubidium environment is highly disordered. Coordination of the hydroxyl groups of namyl alcohol to cations was suggested by EXAFS analysis. XANES analysis was useful in corroborating the EXAFS information and in providing information about the ionic character of the nearest-neighbor bonding.

AbstractCandida cylindracealipase was modified by carboxylic-acid-terminated polymers having different molecular weights, i.e., poly[(N-acetylimino)ethylene] (2a), poly[(N-propionylimino)ethylene] (2b) and poly-[(N-sobutyrylimino)ethylene] (2c). The effect of N-acyl substituent of 2a-con the enzymatic activity of modified lipase (4) for hydrolysis of olive oil and p-nitrophenyl propionate in an aqueous solution and for esterification between n-amyl alcohol and caprylic acid in chloroform, benzene, toluene, and isooctane was examined by using 2a-cof a similar MW (5000–6000). It was found that the active site reactivity of lipase was not as influenced by the chemical modification of lipase in an aqueous medium, and that the rates of esterification were remarkably enhanced, especially in benzene and toluene, by modification with 2bor 2ccompared with the native lipase. The effects of the molecular weight of 2a-cand the average number of 2a-cper molecule of lipase on the enzymatic activity were also investigated.

Abstract: The extraction of Pa(V) from 1M perchloric acid medium with HDEHP in toluene was carried out. The different factors affecting the metal distribution coefficient such as HDEHP concentration in the organic phase, pH of the aqueous phase and the equilibrium temperature were followed. From the data obtained the equilibrium constants of the extraction reaction were calculated. From the temperature variation, the corresponding thermodynamic parameters (DeltaG, DeltaH and DeltaS) were also derived. In the same way, the effect of addition of some N-and 0-containing solvents such as pyridine, 2,2prime-dipyridyl, n-amyl alcohol, n-decyl alcohol and n-butyl acetate, to the HDEHP organic phase was demonstrated. From the data obtained the suggested mechanisms for the synergistic extraction reactions were discussed together with the corresponding values of the thermodynamic parameters.

A simple, rapid and sensitive GC method for the analysis of chloral hydrate in soft elastic gelatin capsules was developed using n-amyl alcohol as the internal standard. The samples were chromatographed using a glass column packed with chromosorb 102 and flame ionization detection. The operating temperatures were 175°, 190°, and 200°C for the column, detector, and injector, respectively. This method was shown to isolate chloral hydrate from its major degradation product chloroform. The method was also compared with compendial and colorimetric procedures. The accuracy, precision, linearity, and applicability to soft elastic gelatin capsules are also presented.

A new extraction–spectrophotometric method has been developed for the determination of trace amounts of phosphorus as orthophosphate. The method is based on the chemistry of 12-tungstophosphoric acid, H3PW12O40(TPA). In the procedure, orthophosphate is converted quantitatively to TPA in aqueous solution at a tungstate–phosphate molar ratio ≥24, in the pHrange 1.2 to 1.9 and in the temperature range 60 to 100 °C. The TPA is subsequently extracted into n-amyl alcohol and its absorbance measured at 267 nm. Beer's law is followed up to at least 25 µg/ml P. The method is less prone to solution conditions and species interference (especially As(V) and Si(IV)) than the widely used molybdenum-blue methods and is competitive in terms of sensitivity, precision, and accuracy. The TPA method was applied successfully to the determination of phosphate in a variety of phosphorus-containing specimens including natural waters, ores, and alloys.Based on potentiometric and spectrophotometric studies, a scheme which accounts for the observed heptaproticity of TPA is proposed.

The breaking of seven ternary acetate-alcohol-water azeotropes by extractive distillation was accomplished. They are n-propyl acetate-n-propanol-water, isopropyl acetate-isopropanol-water, n-butyl acetate-n-butanol-water, 2-butyl acetate-2-butanol-water, isobutyl acetate-isobutanol-water, n-amyl acetate-n-amyl alcohol-water and n-hexyl acetate-n-hexanol-water. The acetates, usually the highest boiling constituents, are obtained as overhead product as a two-phase mixture with water. The most effective agents are glycols and dimethylsulfoxide. Solubility parameters were found to be a qualitative indication for selecting extractive distillation agents. When the formation of a chemical complex is dominant, solubility parameter does not explain solution behavior satisfactorily.

A high-pressure liquid chromatographic method for determining the concentrations of ticarcillin in serum was developed and compared, with 93 patient sera, to a standard agar well diffusion bioassay. For analysis, serum plus temocillin, the internal standard, were extracted with chloroform-n-amyl alcohol and back extracted into phosphate buffer. A reverse-phase C18 column and an ammonium acetate-methanol mobile phase were used with detection at 242 nm. Reproducibility studies yielded coefficients of variation ranging from 2.4 to 4.7% for low, mid, and high controls. Although cefoxitin, cephalothin, and cefuroxime exhibited retention similar to that of ticarcillin, a wide range of commonly administered antibiotics and other drugs did not interfere. The high-pressure liquid chromatographic assay is an accurate, reproducible method for determining the concentration of ticarcillin in serum during multiple antibiotic therapy or when rapid results are required.

Adsorption isotherms are analyzed for slightly soluble organic components from water for a wide range of reduced concentrations. It is shown that the behavior of these systems can be modeled by an equation of the forma = Ac/[(1 +Bc)(1 −c/c0)d] over the range ofc/c0from about 0.05 to 0.9. Hereais the adsorption amount,cis the concentration of organic compound in the water,c0is a solubility limit for the organic compound, andA,B, anddare adjustable parameters. Comparison is made with experimental data for the adsorption ofn-caproic acid,n-valeric acid,n-amyl alcohol,n-butyl alcohol, aniline, cyclohexanol, and phenol from aqueous solutions on carbon adsorbents.

The transport of α-aminoisobutyric acid and K+into K+-depleted cells of a marine pseudomonad (ATCC 19855) was stimulated strongly by ethanol, reduced nicotinamide adenine dinucleotide (NADH), and ascorbate-reduced N, N, N′, N′-tetramethyl-p-phenylenediamine. In the presence of the quinone inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide, only ascorbate-reduced N, N, N′, N′-tetramethyl-p-phenylenediamine was active. Primary and secondary, but not tertiary, alcohols from ethanol to n-amyl alcohol stimulated both α-aminoisobutyric acid and K+transport and were oxidized by the cells. Malate and succinate, which were oxidized rapidly by the cells, had little or no capacity to energize the transport of α-aminoisobutyric acid into K+-depleted cells but were partially effective in promoting K+uptake. Ethanol stimulated the transport of α-aminoisobutyric acid into K+-preloaded cells. The transport of both α-aminoisobutyric acid and K+was inhibited 20% by iodoacetate, 85% by N-ethylmaleimide, and 90 to 100% by both NaCN and p-chloromercuribenzoate. The addition of Na3Fe(CN)6permitted the ethanol-induced transport of α-aminoisobutyric acid into K+-preloaded cells in the presence of NaCN, but little or no uptake of α-aminoisobutyric acid or of K+into K+-depleted cells under the same conditions. The transport of α-aminoisobutyric acid into K+-depleted cells required both K+and an electron donor. The oxidation of NADH and ethanol by K+-depleted cells was stimulated strongly by K+. Parallels between these studies and those with membrane vesicles show that results with membrane vesicles of the marine pseudomonad have physiological significance for the intact cells. The results support the conclusion that the energy for the active transport of both α-aminoisobutyric acid and K+into cells of this organism is provided by electron flow through a region of the respiratory chain lying between cytochrome cand O2.

In order to facilitate the analysis of nonvolatile organic acids by partition chromatography with silica, the relation of solvent composition to the rate of movement of the acids has been investigated. It was found that with chloroform, n-amyl alcohol, and dilute sulphuric acid the logarithm of the peak volume, and hence of the partition coefficient, is proportional to the logarithm of the alcohol concentration. The spread of the zones bears a direct linear relation to the peak volume. A simple graphical method is shown for planning a suitable solvent program for any particular set of acids. Stepwise elution is more suitable than a logarithmic gradient for this type of system.

The influence of tensammetric waves on one another has been investigated by ac polarography. In most of the cases studied, the influence of the more negative tensammetric peak on the less negative peak is due to the greater adsorbability of the surfactant corresponding to the more negative peak on the electrode surface. Ionic surfactants are more efficient in suppressing the less negative tensammetric peak than are non-ionic ones. It is concluded that the effect can be used for comparing the adsorbability of various surfactants in aqueous solution. In some cases the influence is due to chemical interaction between two surfactants to form a complex which is more surface-active than the individual surfactants. It has been possible to estimate the composition of the complex between n-amyl alcohol and o-cresol as 1 : 2, by this technique.

1.A study was made of the reaction for the carbonylation of n-amyl alcohol and isoamyl alcohol using carbon monoxide under pressure in the presence of BF3 hydrates of variable composition.2.The most active and selective catalyst is BF3·2H2O, in the presence of which, under the optimum conditions (100° and 100 atm of CO), are respectively formed the n-amyl and isoamyl esters ofa,a-dimethylbutyric acid in a yield of 73.6 and 90.3%.3.A homogeneous reaction mixture is obtained in the presence of BF3·H2O, which separates into layers of the catalyst and reaction products only when water is added. In the presence of the other BF3 hydrates such separation into layers occurs without the addition of water.

Summary A new technique for the extraction and quantitative determination of the ferric iron chelate of ethylenediamine di(o-hydroxyphenylacetic acid) from aqueous plant extracts is described. The metal chelate is salted out with ammonium sulfate and then is extracted into a small volume of n-amyl alcohol. Spectrophotometric data indicate that the extracted chelate has an absorption maximum corresponding to the iron chelate in aqueous solution and adheres to Beer's law in the range of 0 to 150 micrograms of the metal chelate. The chelate, being anionic in nature, can be absorbed and desorbed from an anion-exchange resin. Isolation and determination of the iron chelate in tomato tissues also is described. Recovery of the iron chelate from these tissues was 94 to 97 per cent.

A sensitive spectrofluorometric assay of sotalol·HCl (d,l-4-(2-isopropylamino-1-hydroxyethyl)methanesulfonanilide hydrochloride; MJ 1999), a potent and specific β-adrenergic blocking agent, was developed. The compound fluoresces in alkali at 250/350 nm. and in acid at 235/309 nm. The maximum extractability was found at a pH of 9, where the substance is primarily the zwitterion with potentiometric pKa' values of 8.30 and 9.80, where the former has been spectrophotometrically assigned to the dissociation of the conjugated sulfanilino group. A mixture of n-amyl alcohol and chloroform (1:3, v/v) at a volume ratio of organic solvent and pH 9 buffer solution of 8:1 extracted 85% of the compound, which was completely reextracted into 5.2 NHCl. The fluorescence of the monocharged molecule was measured at 235/309 nm. in the acid solution. The sensitivity of the assay was 0.1mcg./ml. in plasma and 2.5mcg./ml. in urine. Statistical analyses of assays of sotalol-spiked plasmas, urines, and acidic extraction blanks showed no dose × day interactions and no significant variations of the slopes of calibration curves within 3-4 days of assay; no significant assay differences when the drug was stored under refrigeration in water, acidic extraction blanks, whole blood, plasma, serum, and urine for 2-6 days; and no significant effects from blood and urine obtained from different dogs. The recovery of the drug was 69.4% from plasma and 81% from urine. The sensitivity of 0.1 mcg./ml. in plasma and 2.5mcg./ml. in urine and the reproducibility of 2% at a midrange concentration of 0.5mcg./ml. in plasma and of 2.2% at a midrange concentration of 10mcg./ml. in urine allow the assay to be applicable for monitoring blood levels and urinary excretion of the drug when administered in therapeutic amounts.

In order to facilitate the analysis of nonvolatile organic acids by partition chromatography with silica, the relation of solvent composition to the rate of movement of the acids has been investigated. It was found that with chloroform, n-amyl alcohol, and dilute sulphuric acid the logarithm of the peak volume, and hence of the partition coefficient, is proportional to the logarithm of the alcohol concentration. The spread of the zones bears a direct linear relation to the peak volume. A simple graphical method is shown for planning a suitable solvent program for any particular set of acids. Stepwise elution is more suitable than a logarithmic gradient for this type of system.

Abstract: For the determination of very low concentrations of copper in tin, an analytical method involving reactor neutron activation was developed whereby the copper activity was separated from the tin matrix by extraction of the Cu(I) cuproin complex in n-amyl alcohol. A new decontamination technique was sought in order to remove the copper contamination present on the tin surface. Pre-irradiation removal of the tin surface combined with post-irradiation etching appeared to be the most efficient.

It was found that short-term treatment of unstressed acrylate AST-T samples with n-amyl alcohol and butyl acetate leads to a marked improvement in their mechanical properties. The influence of temperature, holding time, and the nature of the solvent on the strength of acrylate AST-T has been studied. The increase in the strength indexes is the result of the thermal effect of the medium on the molecular structure of the surface layers and healing of the surface defects of the material. The great importance of the state of the surface on the physicomechanical properties compared with the temporary plasticizing action of the solvents has been shown.