Ethanol, detection paper chromatography

Also Tojo and Uenoyama (T2) by means of paper chromatography detected neither 5-hydroxyanthranilic acid nor its conjugate forms in urine of senile cataract patients. They found, however, an ethanol-extractable substance giving a positive ninhydrin reaction and Rf value coinciding with that of tryptophan. The oral administration of a dose of anthra-nilic acid did not alter their findings. 

Before discussing the various derivatives that have been used, it should be remembered that oligosaccharides are often obtained by chromatography on paper or on cellulose columns, and this may cause them to become contaminated by xylan this may be eliminated by extraction of the crude fractions with hot ethanol.474 For similar reasons, glucose that is really extraneous may be detected in fractions separated by electrophoresis on cellulose acetate.475 Gas-liquid chromatography was used to show the presence in pituitary glyco-... 

Test for Carbamates in Stomach Contents Acidify a portion of the sample widi 2M hydrochloric acid, extract with four times its volume of chloroform, separate the chloroform layer, and evaporate to dryness. Dissolve the residue in 0.5 ml of ethanol and spot a 0.1-ml portion on to a filter paper stain the spot with 0.01 ml oifurfuraldehyde solution, allow to dry, and expose the paper to the fumes of hydrochloric acid for 2 to 3 minutes. A black spot indicates die presence of a carbamate. Meprobamate can be detected and quantified by gas chromatography (p. 15). 

The paper discs (diameter 1 cm), cut from Whatman No. 1 chromatography paper (wear gloves ), are placed in a polystyrene microplate so that the center of the discs and of the wells coincide. One to 2 pi of the protein solution (solubilized in 60% ethanol) is spotted (marked with pencil). After drying, the discs can be stored or used directly for EIA detectability is 1-2 ng/spot. 

Purification and Characterization. The (E)-stilbene obtained is, in most cases, sufficiently pure for characterization. However, this should be confirmed by thin-layer chromatography as ouflined earlier (see Purification and Characterization, Experiment [19A]). If only a trace of the Z isomer is detected, recrystallize the product directly, using absolute ethanol. Collect the recrystaUized material by vacuum filtration using a Hirsch funnel. Maintain the vacuum for an additional 10 min to partially dry the crystalline product. Then place it on a clay plate, or on filter paper, and allow it to dry thoroughly. As an alternative, the product may be dried in a vacuum drying oven (or pistol) for 10-15 min at 30 °C (1-2 mm H. ... 

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