Compounds In Various Solvents Research Articles

A new distillation rate method for determining osmotic activity in dilute solutions, especially of highly reactive solutes

AbstractA new method is described for investigating the osmotic situation of nonvolatile compounds in various solvents with a concentration limit as low as about 10−3 mole/1. The method is based on measuring as a function of time the loss of weight of an evaporator made of porous material wetted with the pure solvent, hanging in the vapour of the solution under investigation. The gas‐free solution is injected by its own vapour pressure through a crystal‐seal in an evacuated glass apparatus, having no ground joints or valves. Calibration data are given.

Solid-Solid Interaction Studies by Spectral Reflectance

Spectral reflectance measurements show that the concept of the effect of solvents on the electronic absorption spectra of carbonyl compounds in various solvents as interpreted by polarization theory can be extended into model solid-solid systems, and that slow interaction between a powdered solid and an active adsorbent permits the detection of spectral changes which may be used for kinetic studies of the process of adsorption.

光学異性体の直接分割に関する研究 (第1報)

In order to examine the direct resolution of dl-threo-1-p-nitrophenyl-2-amino-1, 3-propanediol reported by Amiard and others, its racemic structure was examined by thermal analysis and infrared absorption spectrum, and it was revealed that the racemic compound is a racemic conglomerate. Solubility of this compound in various solvents was measured and, from its solubility in water, heat of differential solubility was calculated. From the theory of Meyerhoffer, the racemic compound of this substance was proved to be a racemic conglomerate.

Studies on Haematoxylin and Haematein, the Colouring Principles of Logwood: I–Absorption Spectra of Pure Compounds in Various Solvents and a Spectrophotometric Method of Analysis for Haematoxylin and Haematein

A modified method is described for the preparation from logwood extracts of pure haematoxylin. The criterion of purity is the ultraviolet absorption spectrum in methanol. In most solvents with low ultraviolet absorption, haematoxylin is either too insoluble or too susceptible to oxidation for suitable spectra to be obtained without special precautions.The salient features of the visible and ultraviolet absorption spectra of haematein (about 10 mg. / litre) in six solvents are given. In most of these haematein is eventually oxidised to give a product with a characteristically different spectrum. Solutions in dimethylformamide containing 1 % of a phosphate–citric acid buffer are sufficiently stable for the haematein content to be determined by reference to the peak at 440 mμ. instead of the previously used peak at 280 mμ., which is shown to be unsuitable.Examples of the application of the analytical method to commercial materials are given.

Isolation, detection and measure of microgram quantities of labeled tissue nucleotides

Detailed methods for the isolation, detection, and measure of tissue nucleotides by procedures appropriate to radiochemical investigation have been presented. The isolation technique involves a preliminary quantitative group separation on Norit and subsequent resolution of individual components by two-dimensional paper chromatography. The procedures provide sensitivity appropriate to small tissue samples and products of high radiochemical purity. Additional information has also been presented concerning ( a) reactions of Norit A with purine and pyrimidine compounds in general, ( b) Chromatographie behavior of these compounds in various solvents, ( c) identification and specific activity of isolated nucleotides of rat organs, and ( d) an evaluation of the over-all procedures.