[Increasing the threshold sensitivity of the spot detection reaction on a chromatogram]. / Povyshenie porogovoi chuvstvitel'nosti reaktsii otkrytiia zon na khromatogramme

A known analytical procedure was used for increasing the sensitivity threshold of the reaction of the zone opening on chromatogrammes. The procedure was the following: the carboxylic acid admixtures determined chromatographically were previously extracted from dry samples of the test-compounds into an optimal solvent. The expediency of the procedure was shown on examples of phenylacetic, phenoxyacetic and isoxasolcarboxylic acids present as admixtures in semisynthetic penicillins and raw materials used for their preparation. The threshold sensitivity was increased by 6 to 9 times. The chromatographic separation was performed in a fixed layer of Silica Gel KSK treated with a buffer. The mobile phase was used in the form of a solvent system: n-heptan-glacial acetic acid (95:5).

[Chromatography of penicillins on a thin layer of sorbents. The utilization of "Silufol" plates]. / Khromatografiia penitsillinov v tonkom sloe sorbentov. Ispol'zovanie plastin "Silufol" plates

Carbon metabolism of P. chrysogenum under conditions of periodical addition of the nutrients was studied. It was found that a proper rate of the carbon source addition to the culture was of significant importance for intensive biosynthesis. The use of carbon for the energetic and constructive needs was not the same at different fermentation periods.