Über die Autoxydation von Linolsäure-methylester in Wasser III: Chromatographische Auftrennung der wasserlöslichen Reaktionsprodukte

On the Autoxidation of Methyl Linoleate in Water III: Chromatographic Separation of Water-Soluble Reaction Products From the water-soluble reaction product, which is formed by the autoxidation of methyl-9,12-linoleate in water, 20 substances were preparatively isolated in pure form with the help of adsorption column chromatography. The conditions employed in the isolation of these substances are given in details.     

40%乙·二·扑乳油的气相色谱分析

4 0 %乙·二·扑乳油是以乙草胺、2 ,4 -滴丁酯和扑草净为有效成分复配加工而成的新型除草制剂。本文提出了测定其有效成分的气相色谱分析方法。此法快速、准确 ,为控制乙·二·扑乳油的产品质量提供了准确的分析数据     

Characterization of coal—liquid fractions. Molar enthalpies of quinoline interaction with coal-derived asphaltenes and heavy oils

The toluene-insoluble (Tl), asphaltene (A), and heavy oil (HO) fractions were isolated from three centrifuged SYNTHOIL liquid product (CLP) samples, prepared under different process conditions at 450 °C, 27.6 MPa hydrogen pressure from the same feed coal, Kentucky hvAb, from Homestead Mine. Run FB 53 was made with CoMo catalyst, 11-min preheater residence time, and 3-min reactor residence time. The much higher viscosity of FB 53–59 compared to FB 53-1 correlates with the larger contents of its toluene-insolubles and asphaltene, larger oxygen and sulphur contents of its asphaltene and toluene-insolubles, larger molecular weight and smaller aromaticity of its asphaltene, and the larger enthalpy of interaction (ΔH^o) of its asphaltene with quinoline in benzene. The average molecular weight and percentage of heteroatoms of the heavy oil from FB 53–59 are also greater than that from FB 53-1, and the value of ΔH^o of the heavy oil with quinoline, follows the same order. Run FB 57 was made with glass pellets, 17-min preheater residence time and 6-min reactor residence-time. Since in FB 53–59 the CoMo catalyst has lost part of its activity, a comparison of FB 53–59 with FB 57 yields information on the effect of residence times on the properties. The toluene-insoluble and asphaltene contents, as well as the viscosity, of FB 53–59 is larger, while the heavy oil content of FB 53–59 is smaller than that of FB 57. This comparison indicates that a larger-residence-time preheater and reactor may, to some extent, favour conversion as well as decrease the viscosity of the product oil. The values of ΔH^o for the interaction of quinoline with the heavy oil and asphaltene fractions obtained from the three CLP samples are in the order: FB 53–59 > FB 57-42 > FB 53-1, and they are attributed to the varying degree of hydrogen-bonding effects involving largely aromatic phenols which serve as hydrogen donors to quinoline.     

Nonionic detergent degradation. i. thin-layer chromatography and foaming properties of alcohol polyethoxylates

The thin-layer Chromatographic method for determination of nonionic detergents has been used for the chemical assessment of alcohol polyethoxylates and material derived from them during degradation under simple laboratory conditions. Foaming capacity during degradation was also measured on a representative selection of the materials under test. With one exception (a material with a highly branched alkyl chain) the disappearance of all the alcohol-ethoxylates tested was rapid; a small increase in time required for complete disappearance was observed with the more highly ethoxylated materials, and with the materials which had some slight branching in the alkyl chain. Residues of the polyethylene glycol type, which were generally more persistent than the original materials, were observed to build up as the original materials disappeared, increasing ethoxylation present in the original material giving rise to increasing quantities of residues. The foaming capacity at every stage of the degradation, that is, foam formation alone or synergistic effect on foam formation because of other detergents, could be closely correlated with the results obtained by using the thin-layer Chromatographic procedure.     

Characterization of polynuclear aromatic hydrocarbons in bitumen,heavy oil fractions boiling above 350 °C by g.c.-m.s.

The separation and characterization of polynuclear aromatic hydrocarbons of five fractions of bitumen, heavy oils and synthetic fuels boiling > 350 °C were performed using a combination of Chromatographic techniques. The polynuclear aromatic hydrocarbon fractions were obtained by liquid-solid chromatography and prior to the high performance liquid chromatography and gas chromatography/mass spectrometry techniques, the fractions were subjected to an acid/base extraction procedure to remove polar material. In total, 97 polynuclear aromatic hydrocarbons were tentatively identified by a correlation of their mass spectra and retention indices with those of 25 model polynuclear aromatic compounds.     

Modellierung und effektive numerische Simulation von chromatographischen Trennprozessen im SMB-Betrieb

Modeling and Efficient Computational Simulation of Simulated Moving Bed Chromatographic Separation Processes . Chromatographic separation processes provide a powerful tool for the separation of mixtures in which the components have different adsorption affinities, especially when high purities are required. In this area, simulated moving bed (SMB) technology is becoming an important technique for large-scale continuous chromatographic separation processes since it provides the advantages of a continuous countercurrent operation while avoiding the technical problem of a true moving bed. Because of the complex dynamics of the process, the choice of the optimal operation parameters and the control of the process in order to keep the product specifications at any time is not straightforward. For this challenging task, a reliable dynamic model of the process is necessary which is accurate enough as well as efficient enough in order to permit its online use for model based control. The purpose of this contribution is to review the state of the art in dynamic modeling of SMB chromatographic separation processes, highlighting new trends and results in the design of computationally effective simulation models suitable for online applications.     

Cuticular hydrocarbons of the screwworm,Cochliomyia hominivorox (Diptera: Calliphoridae)

A novel series of 2,X-dimethylalkanes were isolated and identified. The nonpolar fraction of the surface lipids secreted by the adult (5-day-old) screwworm,Cochliomyia hominivorax, contains over 130 different hydrocarbons comprising normal alkanes (32% of the total hydrocarbon), branched alkanes (53%), and monoalkenes (11%). Branched alkanes included monomethylalkanes with substitution in all possible positions except for 4-methylalkanes, internally branched dimethylalkanes, and 2,X- and 3,X-dimethylalkanes. At emergence, adults of both sexes of the 009 strain have nearly identical gas Chromatographic profiles, which diverge as the insect ages. Irradiation of pharate pupae does not affect the hydrocarbon produced.Mention of a commercial or proprietary product in this paper does not constitute an endorsement of that product by the USDA.     

Electrooxidation of benzyl alcohol and benzaldehyde on a nickel oxy-hydroxide electrode in a filter-press type cell

The electrooxidation of benzyl alcohol and benzaldehyde in alkaline medium was carried out in a filter-press type cell on a nickel oxy-hydroxide electrode under different experimental conditions. An overpotential occurs in the presence of organic molecules in the solution shifting oxygen evolution towards higher potentials. The results obtained were conclusive that benzyl alcohol and benzaldehyde electrooxidation on NiOOH layers yielded benzoic acid as the main final reaction product. Chromatographic analysis of the bulk solution showed that the electrocatalytic oxidation of harmful molecules was carried out until the formation of acid compounds (benzoic acid) as an ultimate stage, suggesting that a Ni anode can be used successfully for waste remediation.     

Rapid analysis of vegetable oil flavor quality by dynamic headspace capillary gas chromatography

A rapid capillary gas Chromatographic headspace technique using a multiple purge and trap system was developed and applied for the determination of vegetable oil flavor quality. Oil volatiles were purged at 150°C for 20 min, collected over a Tenax trap and subsequently desorbed and reconcentrated in a series of two smaller traps. From the gas Chromatographic profile, three compounds, t-2-heptenal, t-2-octenal and t,t-2, 4-decadienal were selected for computation of the flavor score of individual oil samples. Analysis of the flavor quality of soybean oil by this technique demonstrated a very good correlation to the traditional sensory evaluation procedure. Good correlation was also observed for the flavor evaluation of corn oils. Precision, based on multiple analyses of known standard aldehydes, was shown to be better than 6%. The degree of Chromatographic efficiency obtained by this multiple concentration technique permitted the use of a short 25-min Chromatographic run in the resolution of these aldehydes of interest. This approach reduced the overall analysis time of existing instrumental oil flavor techniques significantly.     

Mössbauer spectroscopy of iron in coal and coal hydrogenation products

The chemical states of iron in a Kentucky coal and in the products of its hydrogenation were determined by Mössbauer spectroscopy. The iron in the coal was present chiefly as pyrite, FeS₂. There was, however, evidence for some non-pyritic iron, most likely present as szomolnokite (FeSO₄·H₂O). The products from hydrogenation of this coal by the SYNTHOIL process at 723° K and 28 MPa contained all the iron as FeS_x where x = 1.0 to 1.14. There was no evidence for unreduced FeS₂ or FeSO₄. There was also no evidence for elemental iron. At the experimental conditions for hydrogenation of coal in this work, the reactor gas contained 0.32% H₂S. Evidently, FeS_x is not reduced to elemental iron in the presence of this concentration of H₂S in the reducing gas.     

Gaschromatographische und dünnschichtchromatographische Untersuchung von Fettsäuren: Die Anwendung von gepackten Glaskapillarsäulen zur Trennung von cis- und trans-ungesättigten Fettsäuren

Gas Chromatographic and Thin-Layer Chromatographic Studies on Fatty Acids: The Application of Packed Glass Capillary Columns for Separation of cis- and trans-Unsaturated Fatty Acids from Saturated Fatty Acids Packed glass capillary columns were used for the quantitative determination of trans- and cis-unsaturated fatty acids in the presence of saturated fatty acids by gas chromatography. The fatty acids were analyzed as methyl esters after interesterification of the triglyceride samples. The conversion of glyceryl esters of fatty acids into methyl esters could be followed using short GC columns and by thin-layer chromatography.     

Production of cocoa butter-like fat from interesterification of vegetable oils

Cocoa butter-like fat was prepared from completely hydrogenated cottonseed and olive oils by enzymatic interesterification. The optimum reaction time to produce the major-component of cocoa butter, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS), was 4 hr. The cocoa butter-like fat was isolated from the reaction mixture by two filtration steps. The yield of cocoa butter-like fat was 19%, based on the weight of the original oils. Chromatographic analysis of the product by reversephase high-performance liquid chromatography (HPLC) has shown it contains triglyceride components similar to those of cocoa butter, but that it has slightly more diglycerides. The melting point of this product, as measured by a differential scanning calorimeter, is 39°C, which compares well to the 36°C melting point of natural cocoa butter. Presented in part at the AOCS meeting in Cincinnati, Ohio, in 1989.     

Epoxid-Reaktionen. V. Untersuchung von Teilreaktionen der Epoxidharz- Vorprodukt-bildung durch chromatographische Methoden

Epoxide Reactions. V. Chromatographic Studies of Some Reactions Involving Epoxide Formations A reverse phase liquid chromatographic method has been applied for the quantitative determination of some products in epoxide forming reactions. The reaction of chlorohydrinethers of bisphenol A with aqueous sodium hydroxide has been studied quantitatively under different conditions. The influence of side products originating from epichlorohydrin on the course of the main reaction is discussed. In addition preparative liquid chromatographic methods have been developed to separate epoxide oligomers and some chlorohydrinethers of bisphenol A.     

Characterization of polynuclear aromatic and aliphatic hydrocarbon fractions of solvent-refined coal by glass capillary gas chromatography/mass spectrometry

Separation and identification of the polynuclear aromatic and aliphatic fractions of solvent-refined coal and its recycle oil were performed using a combination of solvent partition and Chromatographic fractionation procedures with glass-capillary gas chromatography (g.c.)/mass spectrometry (m.s.). Chromatographic profiles were generated for each fraction, and some semiquantitative data were also obtained. In total, 146 polynuclear aromatic components of SRC were tentatively identified by their molecular weights, as indicated by the mass spectra of the g.c. peaks. In addition, whereever possible specific isomers have been indicated, based on comparison of spectral characteristics and retention data.     

Bienenwachs – Zusammensetzung und Beurteilung der Reinheit durch gaschromatographische Analyse

Beeswax – Composition and Determination of Purity by Gas Chromatographic Analysis Beeswax, a product of the honeybee Apis mellifica, is one of the most ancient natural waxes in use. Beeswax consists of 70–80% of fatty acid-and hydroxy fatty acid esters of higher alcohols, 10–15% free fatty acids and 10–20% hydrocarbons. By gas chromatographic analysis about 65% of the nonhydrolysed wax can be detected. The remaining fraction contains mainly nonvolatile di- and triesters. A complete analysis of the components of beeswax is obtained after hydrolysis and silylation of the wax. The chromatograms of beeswax show characteristic patterns. Addition of foreign substances and adulteration can be detected easily.     

以鸡胸软骨为原料提取硫酸软骨素的研究

以鸡胸软骨为原料,在60℃下用木瓜蛋白酶水解除去蛋白质,再用乙醇沉淀获得鸡胸软骨多糖。色谱分析和聚丙烯酰胺凝胶电泳鉴别显示,鸡胸软骨多糖主要是硫酸软骨素,表明鸡胸软骨是可行的硫酸软骨素新来源。     

High molecular weight substance profiles obtained from fossil fuels with microcolumn liquid chromatography

Simple procedures have been developed for the Chromatographic profiling of the non-volatile fractions from fossil fuel materials. Highly efficient microcolumn liquid chromatography in the reversed-phase mode has been employed to resolve numerous neutral polyaromatics, aza-arenes and phenolics into distinct Chromatographic profiles. The range of compounds eluting was verified through mass spectrometry. Such profiling methods are of importance in estimating technological and environmental parameters for various fossil fuels.     

The electrochemistry of coal and coal liquids. II. Cyclic voltammetry of H-coal liquids

The electrochemical behaviour of three H-coal liquids, ASO, ASB and VSO, has been characterized by cyclic voltammetry at glassy carbon electrodes. Voltammograms obtained for the three intact coal liquids in methanol/water solution showed a broad, irreversible anodic wave at +0.5 V versus saturated calomel electrode. In order to determine which components of the coal liquids were primarily responsible for the observed electrochemistry, two column chromatography procedures were employed to separate the ASO, ASB and VSO into several fractions on the basis of functional group content. Subsequent cyclic voltammograms recorded for the resulting chromatographic fractions exhibited substantial anodic current only for the fractions designated as containing predominantly aromatic, polar aromatic/N-heterocyclic, and monophenolic components. Of these, the phenolic fractions appeared to account largely for the +0.5 V wave observed for the intact coal liquids. Chromatographic fractions corresponding to other functional groups exhibited only slight electrochemical activity, or none at all, under the conditions employed.     

Reactions of dimethyl sulfoxide with sulfonate esters of fatty alcohols. I. Synthesis of higher saturated and unsaturated fatty aldehydes

Long-chain saturated fatty aldehydes (C₁₀ to C₁₈), as well as the C₁₈ unsaturated aldehydes (oleyl, linoleyl, and linolenyl), were synthesized in good yields by the selective oxidation of the sulfonate esters of the corresponding alcohols with dimethyl sulfoxide in the presence of sodium bicarbonate. Chromatographic procedures for the isolation of the pure aldehydes from the reaction mixtures are described. The purity of the aldehydes was ascertained by thin-layer chromatography, melting points of their 2,4-dinitrophenyl hydrazones, infrared spectra and other physical methods. Presented at the AOCS Meeting in Houston, April, 1965.     

Chromatographie analysis of seed oils. Fatty acid composition of castor oil

The fatty acid composition of a number of domestic and foreign castor oils was determined by consecutive column and gas-liquid Chromatographic analysis. After saponification of the oils and removal of the unsaponifiables, the nonhydroxy, monohydroxy, and dihydroxy acids were fractionated by partition chromatography on silicic acid. The amount of acid in each fraction was determined by titration or weighing. Gravimetric data were in good agreement with the titrimetric data. The acids obtained by saponification were converted to methyl esters with diazomethane and similarly subjected to partition chromatography. The methyl esters from various fractions were analyzed by gas-liquid chromatography. Components were tentatively identified by their comparative retention times and confirmed Presented at the AOCS meeting in Chicago, 1961. A laboratory of the Western. Utilization Research and Development Division, Agricultural Research Service, U.S.D.A.