Bestimmung von flüchtigen Fettsäuren durch GC-MI-FTIR – Kombination von Gaschromatographie mit FTIR-Spektroskopie nach der Technik der Matrixisolation

Examination of Matrix Isolated Fourier Transform Infrared Spectras of Volatile Free Fatty Acids IR-spetroscopy in organic analytic is a well known method for the determination of functional groups and the identification of organic molecules. Sensitivity is especially high, when polar compounds are investigated. One of the few exceptions are the fatty acids. Due to the dimerisation of the carboxyclic group, part of the interesting range of the spectrum is covered by this dimer band. Moreover, the interpretable part of the spectrum is only of moderate resolution. By using GC-MI-FTIR, low temperature IR-Spectra of the fatty acids are available in not yet known resolution. Among the various fatty acids there are a number of structure specific criteria, which allow a definite identification even in trace levels, without previous derivatisation.     

Die Automatisierung von Chemieanlagen mit Mitteln der Systemtechnik – Analysen und Trends

Automation of chemical plant employing techniques of systems engineering – analysis and trends . Automation techniques involving systems have been advancing as a consequence of tremendous progress in microelectronics. Independently, an altered economic situation in the area of chemistry, which can be characterized by more stringent demands with respect to product quality, is extending the goals of automation, again requiring the methods of systems engineering for their realization. This completes a circle which should also encompass the organization of the departments responsible for automation and related concepts, solutions, and sophisticated engineering methods.     

Schnelle und präzise Bestimmung des Gesamtglucosinolatgehaltes von Rapssamen-Vergleich der Röntgenfluoreszenzanalyse mit Gaschromatographie und Hochdruckflüssigkeitschromatographie

Rapid and Precise Determination of Total Glucosinolate Content in Rapeseed – Comparison of X-Ray Fluorescence Spectroscopy with Gaschromatography and High-Performance-Liquid-Chromatography The introduction of oilseed-rape cultivars poor in glucosinolates within the EG requires methods which allow a separation of the yield batches by the glucosinolate content. By means of the indirect determination of the glucosinolate content by X-ray-spectroscopy a method is introduced that produces a high correlation with conventional procedures (r² = 99% for GC-reference samples, r² = 92% for GC single data, r² = 96% for HPLC single data; deviations from average values: GC-reference samples 1.3%; single analyses of GC and HPLC 7.4 respectively 3.1%) and that needs only 4 minutes for one complete determination and is easily to perform.     

Die Bestimmung der Schmelz- und Erstarrungs- Temperaturen von Fetten

Determination of Melting and Solidification Temperatures of Fats Considerable fluctuations in results are observed when solidification temperatures, and, especially melting temperatures are determined by customary methods. In an apparatus developed by Walisch and Eberle, the sample is heated in an oven under linear increase in temperature, during which the temperature within the sample is measured. In pure glycerides and various fats, the resulting temperature-time curve enables detection of the polymorphic crystalline transformations and determination of the entire temperature region at which melting occurs. Reproducibility of the results was very good. In parallel studies using NMR-spectrometry, the amount of liquid part as a function of temperature was measured. The results agreed with melting diagrams. The cooling curve served for determining solidification point in a most reproducible manner and for detecting polymorphic transformations.     

Bestimmung der Oxidationsstabilität von Fetten und Ölen – Vergleich zwischen der Active Oxygen method (AOCS Cd 12–57) und der Rancimat-Methode

Determination of the Oxidative Stability of Fats and Oils-Comparison between Active Oxygen Method (AOM) and Rancimat Method Oxidative stability is an important parameter for the characterization of fats and oils. The Active Oxygen Method (AOM) can be used to determine this parameter. However, the periodic determinations of peroxide number required with the AOM render this method expensive and labour-intensive. The alternative Rancimat Method is based on the conductometric determination of the volatile decomposition products. As the periodic titrations for the determination of the peroxide number are not necessary, Moreover, in contrast to the AOM, the Rancimat Method does not require expensive chemicals. The induction times t_I determined with the two methods using six different fats and oils show a good correlation. This means that the Rancimat Method gives results equivalent to those of the AOM Method and offers an attractive alternative.     

Struktur — Retentionsbeziehungen von stereoisomeren methylsubstituierten Isochromanen in der Gaschromatographie

Structure - Chromatographic Retention Relationships of Stereoisomeric Methyl-substituted Isochromanes Retention times of 13 mono-, di- and trimethylsubstituted isochromanes are determined on both polar (PEG) and nonpolar (OV-1) stationary phases and KOVATS retention indices (I) are calculated. The significant retention index differences (ΔI) between stereoisomers (up to 30 units) are discussed with respect to the configurational and conformational arrangement of the substituents. Retention indices determined by gas-solid-chromatograhpy (GSC) on graphitized thermal carbon black (GTCB) complete the research.     

Dünnschicht- und Gaschromatographie von Tocopherolen

Thin-Layer end Gas Chromatography of Tocopherols Oilseeds, to which an internal standard of tocopherol was given, were extracted for tocopherols with ethanol under conditions inhibiting oxidation using an Ultra-Turrax homogenizer. After filtration the ethanolic extract is briefly saponified and the unsaponifiable matter containing the tocopherols extracted into n-hexane. Then the hexane-fraction is washed alkalifree with water, dried over Na₂SO₄, concentrated and applied on a silicagel GF₂₅₄-plate, which is developed with dichloromethane. With co-chromatographed reference-tocopherols on the margins of the TLC-plate the presence of tocopherolquinones can be checked in UV-light, whereas the bands of tocopherols and tocotrienols are located by spraying the margins with Emmerie and Engel-reagent. The corresponding zones were scrapped off the plate, the silicagel extracted with 15 × 1 ml ethanol, the ethanol evaporated to dryness and the residue derivatised to trimethylsilylethers. Gaschromatography on 3 m SE-52/XE-60 or 1.5 m SE-30 columns gave a good separation of tocopherols and tocotrienols. Simultaneous qualitative and quantitative determination of tocopherols by GLC combined with the possibility of automation makes this analytical procedure superior to TLC and colorimetry of tocopherols. About 500 tests with different oilseeds in the range between 50-800 mg lipid and 20-2000 μg of total tocopherol/sample gave a recovery of 60% at a coefficient of variation of approximately 6%.     

Vergleichende Untersuchungen zur Bestimmung der sauren Oberflächenoxide von Gasrußen

An attempt is made to quantitatively determine acidic surface oxides on some carbon blacks. The applicability of some analytical methods is discussed. The results of neutralisation reactions suggest that four different surface groups exist. It is taken as reference method. Because of this very slow method it is discussed whether there exist some faster and comparable methods. A comparison is done to investigate changes in surface groups of a special chemically treated, bleached carbon black. To impart jetness to paint films carbon blacks are widely used. To treat carbon blacks with a special chemical process may influence the stability of black paint systems. The surface groups of carbon blacks vary in their acidity. Neutralisation reactions with bases of different strength, an indirect titration, are compared with direct titration in a non aqueous solution and with silylation reactions.     

Die Bestimmung der Enzymaktivität von enzymhaltigen Waschmitteln

Determination of Enzyme Activity of Enzyme-Containing Washing Agents Four analytical methods for the determination of the proteolytic activity of detergents and enzymes for use in detergents have been compared. They were the following: 1) Determination of casein hydrolysis products by UV spectrophotometry; 2) Determination of azocasein hydrolysis products by colorimetry; 3) Determination of casein hydrolysis products by UV polarimetry; 4) Titration of casein hydrolysate. The activity of the enzymes can be increased or decreased by components used in detergents. Perborate especially interferes strongly. The polarimetric method is the most accurate and the simplest, but necessitates expensive equipment. The spectrophotometric and colorimetric methods are more accurate and reproducible than the titrimetric method.     

Bestimmung der Molekül- und Kristallstruktur sowie der Absolutkonfiguration von Peganin

The Crystal and Molecular Structure of Peganine. Estimation of its Absolute Configuration The crystal and molecular structure of (-)-peganine hydrochloride 2 have been determined by X-ray structure analysis. Furthermore the absolute configuration of this alkaloid was deduced with the aid of the anomalous scattering at the Cl-atoms. The pyrrolidine ring of 2 has envelope conformation. 2 possesses R -configuration.     

75 Jahre Hydroformylierung – Oxoreaktoren und Oxoanlagen der Ruhrchemie AG und der Oxea GmbH von 1938 bis 2013

The hydroformulation reaction, also known as oxo synthesis or Roelen reaction, is the atom‐efficient and metal‐catalyzed addition of the constituents of synthesis gas, H₂ and CO, to the double bonds of alkenes. This reaction has been discovered in 1938 by Otto Roelen in the laboratories of the chemical company Ruhrchemie AG. After filing the patent application efforts to scale up the process to technical scale have been started. However, they have only partly been successful for the plants of the Ruhrchemie AG Oberhausen and its cooperation partner I.G. Farbenindustrie AG due to the difficult circumstances. After World War II the Ruhrchemie process based on cobalt catalysts and the Ruhrchemie/Rhône‐Poulenc process as the first important aqueous two‐phase processes with rhodium catalysts became the most important homogenously catalyzed chemical processes.