When diethylen glycol succinate polyester was used as stationary liquid phase of gas chromatography, the influences of various factors on the separation of methyl stearate and oleate peaks were investigated for both thermal conductivity detector and hydrogen flame ionization detector. Our experiments showed the following results. The degree of polymerization of polyesters slightly influenced upon the column efficiency in the range of molecular weight from 2, 700 to 5, 400. Rather, the influences of the procedur for supporting the polyesters on the solid supporters were considerable, and the species of supporters used had greatest influence upon the column efficiency. When the column became longer, the number of theoretical plates increased but the degree of resolution increased scarcely. Further, the relative responses in flame ionization detector were discussed for methyl esters of palmitic, stearic, oleic, linoleic and linolenic acids. The relative responses showed nearly close correlation between percentages of peak areas and weight percent when their contents were large. But when their contents were small, there was a tendency that percentages of peak areas of methyl stearate and oleate were higher than known weight percent, while percentages of peak areas of methyl linoleate and linolenate were lower than known weight percent.
Activated bleaching earth was tried as an adsorbent instead of silica gel for the thin-layer chromatography (TLC). Good results were obtained in TLC as well as in silica gel from following matter : 1. The mixture of stearyl alcohol, cholesterol and liquid paraffin. 2. The mixture of sperm whale alcohols and cholesterol. 3. Unsaponifiables obtained from woolwax, beeswax, insect wax and sperm whale oil. n-Hexane-ethyl ether (1/1, vol/vol) was better developer than other solvents tested.
In the previous paper the author observed that distillable products are formed when oils are heated at 300°C. The author considered it may be helpfull to elucidate the characteristic changes of heated oil when chemical compositions of this distillable products would be identified. The distillable products consist of acidic, carbonyl and neutral fractions. The acidic fraction mainly consists of free fatty acids. The pattern of fatty acids is resemble to that of original fatty acids composition at the early stage of heating and as the heating time increases the content of lower fatty acids increases. In the neutral fraction more than 15 peaks were observed by gas chromatography. The main components were hydrocarbons, the carbon number of which was 8, 9, 10, 11 and 12. The author concluded that cleavage of ester linkage is dominant at the early stage of heating at 300°C and that the cleavage of oxidative products follow, causing the formation of lower fatty acids.
The effects of heat-treatment on the emulsifying properties of soybean lecithin were studied. Soybean lecithin was heated at 120150°C for 560 minutes. with soybean oil. Chemical properties of heated soybean lecithin, such as the contents of acetone soluble lipid, water soluble compounds containing phosphorus and acid value were determined, and then, the contents of individual phosphatides, were determined by silicic acid column chromatography as described by Hanahan. The phase inversion curves obtained by emulsifying soybean oil with water, and the emulsion stabilities were determined by the residual emulsion volume (ml), after centrifuged at 4, 000rpm for 7 minutes. From the experiments we could conclude that water soluble compounds, such as glycerpylhosphoryl compounds and glycerophosphoric acid, and lysophosphatides were increased with heating, and also heated soybean lecithin could easily make emulsions of O/W type and their emulsions were very stable.
Soybean oil, rape oil and olive oil were heated to 100°C, 190°C and 230°C and the changes in the unsaponifiable matter were examined. From experimental results, it was concluded that the decrease in the unsaponifiable matter was more at higher temperature and for the longer heating time. The decrease in the unsaponifiable matter was about 20 percent at 200°C for 26 hours. In case of autoxidation there was no change. The steroid fraction in the unsaponifiable matter was fled in all directions during the heating process, which was examined by the thin-layer chromatography.
The antibacterial property of alkylbenzene sulfonates (ABS) was studied with E. coli, Staph. aureus and B. subtilis. The adsorption of ABS and cetyl trimethyl ammonium bromide (CTAB) on B. subtilis or E. coli at various pH levels was studied. It was found that ABS was easily adsorbed on those organisms in acidic side but CTAB was easily adsorbed on them in higher pH range. The differences in the growth inhibitory action of ABS and CTAB against Staph. aureus by the difference of pH range were investigated. It was found that the minimal growth inhibitory concentration was 2.5μg/ml below pH 5, 20μg/ml above pH 7 for ABS and 0.255μg/ml above pH 7, 0.51μg/ml at pH 6 for CTAB. From those results, the electrostatic adsorption of the surfactant on bacteria is one of the important factors concerning its antibacterial action. The bactericidal action of ABS and alkyl dimethylbenzyl ammonium chloride (ADBAC) against E. coli and Staph. aureus in nonvegetative stage of growth was studied. It was found that the exponent, n, of dilution coefficient of ABS was 0.20.6 for test organisms, therefore, discussion of bactericidal activity of ABS in comparison with well known phenol coefficient is meaningless. The adsorption of ABS on the organisms, decrease in the number of living organisms, turbidity change of bacterial suspension and permeation of cellular contents, such as proteins and nucleic acid were observed. The turbidity change of liquid medium was observed by addition of ABS in the logarithmic growth phase of Staph. aureus. From these experiments, it is suggested that the permeability change of cell membrane and bacteriolysis resulting from denaturation of cellular proteins due to the adsorption of ABS is included in the mechanisms of the antibacterial action of ABS.
Gas chromatographic analysis of the scission products of trans-octadecenoate and trans, trans-c-onjugated octadecadienoate separated from the products obtained by hydrazine reduction of parinaric acid has shown that parinaric acid have cis-9, trans-11, trans-13, cis-15-configuration.