Hauptkomponenten der 4-Methylsterin- und Triterpenfraktion von 12 Pflanzenfetten und ihr Einfluß auf die Sterinanalyse

Main Components of 4-Methyl-Sterol and Triterpene-Fraction of Twelve Vegetable Fats and their Influence on the Sterol Analysis 4-methylsterols and triterpenes are accompanying substances of the sterols in the unsaponifiable with partly very similar chromatographic properties. In 12 different vegetable fats both content and composition of the main components of these three substance groups were investigated and their influence on the sterol analysis was found out. For most fats a thin-layer chromatographic separation of the 4-methyl-sterols and triterpenes from the sterols is necessary to make possible an exact determination of the sterol content and the sterol composition by gas chromatography.     

Nachweis und Identifizierung von archäologischen Fetten

Indication and Identification of Archaeologic Fats In comparison to the food chemistry, the special tasks of fat indication in archaeologic discoveries consist in regarding possible changes of the fatty acid chains by soil storage. But changes of the composition expressed as percentages need not inevitably occur. There are many examples especially from zoologically determined subrecent bones that the total fat amount is indeed highly reduced, but the remaining residue seems unsignificantly altered. In case of alteration on an empiric basis a solution possibility can be achieved from two sides: pure fatty acid methylates are left to the effects of the natural environment. After some time the occurred changes are analysed. Since because of the relatively short period only introducing changes can be determined, you start from the other end: For archaeological findings enough time for changes has been available. Fats are extracted from objects which were identified by an archaeobotanist as seeds of certain plants or by an archaeozoologist as bones of certain animals and compared with recent fats. Ways of conversion get visible especially by a graduation of the findings according to the age.     

Untersuchungen zum Nachweis von Kakaobutter-Ersatzfetten

Investigations on the Detection of Cocoa Butter Substitutes Coberine, Calvetta and other fats prepared by fractionation, as well as Tenkawang fat have a fatty acid composition which is very similar to cocoa butter. Presence of fatty acids that do not occur in cocoa butter, ratio of C₁₆/C₁₈, as well as composition of sterol fraction serve for chemical identification of the above fats.     

Beiträge zum Vernetzungs- und Abbauverhalten von Acrylelastomeren

The aim of this investigation was to obtain additional knowledge of the curing mechanism and the aging properties of acrylic polymers containing active chlorine. These were cured with amine or metal-soap/sulphur combinations. For this purpose, we used sulphur, chlorine, and nitrogen analyses, together with measurements of crosslink density and stress-relaxation. These investigations were partly made with vulcanisates based on technical acrylic polymers, and partly with crosslinked products of homo- and copolymers containing chlorine. Using the amine curing system, the diamine, after vulcanisation, is completely incorporated. Curing with metal-soap/sulphur combinations sulphur crosslinks are formed. The crosslink density is proportional to the concentration of amine or potassium-stearate in the compound. Comparing polyethylacrylate polymers containing vinyl-chlorecetate and 2chloroethyl-vinylether comonomers one always h d s the higher crosslink densities in polyethylacrylat/vinylchloracetat copolymers. We proved by stress relaxation measurements that scission of the network occurs at the crosslinks during air aging. Using amine as the curing agent oxidativedegradation exceeds the thermal one. In case of metal-soap/sulphur curing system thermal degradation exceeds the oxidative portion. Remarkable differences in aging properties between the two types of polymers could not be found. These results fit with our conception of the types of networks built up duringvulcanimtion, based on the other examinations.     

Die Erkennbarkeit der Verfälschung von Rinderfett mit Pferdefett

Detection of Adulteration of Beef Fat with Horse Fat Fatty acids of pure beef fat and horse fat and their mixtures were isolated and investigated by gas chromatography after methylation. Fatty acids with 14 to 18 C-atoms were determined. Especially, stress was laid on the quantitative estimation of higher unsaturated C₁₈ acids, and from their ratio to other fatty acids some characteristic values were obtained which permit the detection of adulteration of beef fat with horse fat. The octadecene value and hexadecane value were found to be sensitive. By determining these values it is possible to detect the adulteration of beef fat with ca. 5% horse fat.     

Farbmetrische Kennzeichnung der Verfärbung von PVC nach thermischer Belastung

The discoloration of PVC which is observable with increasing thermal treatment has been determined by measuring the colour of samples from four different compounds. It could be shown that the thermal stability of a PVC compound can be characterized by determining the chromaticity coordinate z as a function of the milling time of the samples. Moreover a simple explanation of the typical hue shift from yellow to orange or red, that is associated with the thermal degradation of PVC, could be derived. This hue shift can be explained by assuming the existence of a single chromophore whose concentration increases with increasing thermal treatment of the samples.     

Moglichkeit zum Nachweis der Kontamination von Rinds-und Schweinefett mit Hilfe der gaschromatographischen Bestimmung von Glycerinäthern

The Possibility of. Demonstrating Contamination of Pork Fat and Beef Fat by means of GLC Determination of Glyceryl Ethers An investigation has been carried out in order to establish whether by GLC determination of glyceryl ethers — a group of substances present in small quantities in the unsaponifiable matter of pork fat and beef fat — the purity of beef fat and pork fat can be ascertained. In this connection a “micro” analytical procedure has been developed by means of which the amount of glyceryl ethers as well as their proportional composition can be determined. In each of a number of commercial samples of pork fat and beef fat, investigated according to this procedure, chimyl, batyl and selachyl alcohol were found. However, there are noticeable differences in the total amount and in the proportional composition of these ethers in pork fat and beef fat. This is clearly expressed by the following figures: beef fat was found to contain approximately three times as many glyceryl ethers as pork fat: average quantities of 370 μg/g and 120 μg/g fat respectively; the average selachyl alcohol content in pork fat amounted to 31.6% and to 11.3% in beef fat. The results of the investigation show that the determination of glyceryl ethers do indeed offer prospects for ascertaining the presence of small quantities of beef fat in pork fat.     

Darstellung von Copolymerisaten unter Verwendung von Fettsäurevinylestern und Acrylsäure-Fettalkoholestern und Prüfung als W/O-Emulgatoren

Preparation of Copolymers Using Vinyl Esters of Fatty Acids and Acrylic Esters of Fatty Alcohols and Study of Their Properties as W/O-Emulsifiers Statistical copolymers prepared by radical polymerization of hydrophilic and hydrophobic monomers have proved to be efficient as w/o-emulsifiers. Two examples of these types of substances are described: copolymers of N-vinylpyrrolidone with vinylic esters of fatty acids and copolymers of 2-hydroxyethylacrylate with acrylates of fatty alcohols. The dependence of their properties upon the structure of the polymers was examined. These polymeric emulsifiers enable one to prepare emulsions which are unusually thermostable even in the absence of co-emulsifiers and stabilizers.     

Nachweis und Verfolgung von Membran‐Fouling

Membrane fouling is a negative contamination effect: compounds in the feed solution settle on the membrane surface or in the pores, limiting the efficiency and separation performance of the membranes. This effect occurs for different membrane types such as reverse osmosis, ultra‐, nano‐ and microfiltration membranes. A method is presented how membrane fouling can be identified and tracked based on the zeta potential calculated from flow measurements.     

Untersuchungen zum Abbau von PVC-Folien durch Wärme und Licht

The degradation of films of copolymers of vinyl chloride and carbon monoxide or oxygen by heat and light was investigated. With increasing carbonyl content the instability increases. The thermal degradation is accelerated by oxygen, the photodegradation is retarded. Due to the influence of light polyene sequences are formed on the surface layers of the polymer film. Therefore the lower layers are not damaged.     

Einfluß von Minorbestandteilen des Unverseifbaren auf die Sterinanalyse

Influence of Minor Components of the Unsaponifiable on Sterol Analysis Often the significance of purification of a sterol mixture by thin layer chromatography before the gaschromatographic investigation has been underestimated with respect to exactness of sterol investigations. Most faults occur by 4-methylsterols and triterpenes. These are also parts of the unsaponifiable and partly they have the same retention times as sterols. During purification of sterols 4-methylsterols and triterpenes are not separated from the unsaponifiable by cartridges, either.     

Untersuchungen zum Nachweis von Emulgatoren in Lebensmitteln IX

Investigations on the Detection of Emulsifiers in Foods, 9th Communication Properties and the means for the detection of the emulsifier calcium stearyl lactate have been studied. A simple procedure for specific detection of the same is given.     

Untersuchungen zum Nachweis von Emulgatoren in Lebensmitteln X

Investigations on the Detection of Emulsifiers in Foods X A method is described, which enables the detection and differentiation of food emulsifiers, that are based on glycerides of lactic acid and acetic acid. After extraction, the mono- and diglyceride fractions are isolated and saponified. Subsequently, the acids are separated from the solution and detected by specific colour reactions.     

Untersuchungen zur Kinetik und zum Wärmeeffekt der Cyclotrimerisierung von Arylcyanaten

Studies on the Kinetics and the Reaction Heat of the Cyclotrimerization of Aryl Cyanates The kinetics and the reaction enthalpy of the polycyclotrimerization of 2,2-bis(4-cyanatophenyl)propane in ditolylmethane solution were investigated by means of direct calorimetry, varying the concentration of the catalyst (chromium(III) acetyl acetonate) and of the monomer as well as the reaction temperature, the water content of the solvent, and the amount of added acetyl acetone. The maximum reaction rate is proportional to the monomer concentration, to the square root of the concentration of the catalyst, and to the water content. It is inversely proportional to the amount of water added. Presumably, water participates in the formation of the active species of the catalyst, and the autocatalytic nature of the polycyclotrimerization of 2,2-bis(4-cyanatophenyl)propane in presence of chromium acetylacetonate is due to accumulation of the latter during reaction.     

Bestimmung der Gleichgewichtskoeffizienten und Affinitäten von Anionen zum Wofatit SBW

The equilibrium coefficients and relative affinities of 28 anions on the strongly basic anion-exchanger resin Wofatit SBW has been determined in batches by the conductive method. The practical application of the measured values are qualitatively discussed.