Solvents Butanol Research Articles

Viscosity of non-aqueous solutions of pyridine-containing copolymers

PYRIDYNE-containing copolymers and their salts in aqueous solutions exhibit the properties of polyelectrolytes [1, 2]. In methanol poly-2-methyl-5-vinylpyridine behaves as a non-electrolyte [3]. The salts of pyridine-containing copolymers are also able to ionize in methanol solutions but, according to the data of reference [4], at low degrees of ionization, the aqueous and methanol solutions are different in respect of the dependence of viscosity and electrical conductivity on temperature. The copolymer of 2-methyl-5-vinylpyridine, with 6 0 ~ by weight of divinyl (SKMVP-40), dissolves in hydrochloric acid over a certain concentration range [5] and in certain alcohols, benzene and eyclohexanone. The addition of a concentrated mineral acid to the copolymer solution in an organic solvent results in the precipitation of the polymer from the solution as a gel. In butanol, cyclohexanol and certain other solvents this gel dissolves in time, particularly in the presence of excess acid. When treating dilute alcoholic copolymcr solutions with low concentration of mineral acid, no gel is precipitated but variation of viscosity is observed. SKMVP-40:~ films t reated with strong acids have the properties of a crosslinked polymer [6]. The density of the network apparently formed by hydrogen bridge bonds should depend on the amount of acid absorbed by the copolymer. Since hydrogen bridge bond formation in the films leads to a considerable increase in strength and hardness, it was expected that salt-formation in solutions would involve a certain variation of viscosity. A study has been made in this section of the variation of viscosity in non-aqueous SKMVP-40 copolymer solutions under the effect of HC1. EXPERIMENTAL SKMVP-40 copolymer was separated by drying latex as free films which were carefully washed from impurities and low-molecular weight fractions by boiling in water and then with acetone. The copolymer dried in vacuo was dissolved in butanol, or another solvent,

Zone migration in paper chromatography

The influence of concentration gradients upon zone migration has been investigated theoretically and experimentally. It is shown that the equation R F = A M /(α A S + A M ). is incorrect in relating the R F to the partition coefficient α. The R F shows an initial unsettled period during which it approaches a limiting R F value. Both the limiting and transient values were calculated for the migration of Methyl Orange on Whatman 3 MM paper with a water-saturated butanol solvent. Cases of radial flow with variable length wicks also treated. Using the data from rectangular flow, R R values were successfully predicted for the same Methyl Orange system. The reasons for deviation from the relationship R R 2 = R F were discussed.

Effect of Trichloracetic Acid on Adrenaline Chromatograms

EXTRACTS free from blood and protein are readily prepared for biological estimation by grinding suprarenal glands with 5 or 10 per cent aqueous trichloracetic acid and centrifuging. However, on submitting such an extract from a cat to paper-partition chromatography using as solvent butanol : acetic acid : water (4 : 1 : 5), we observed that development with aqueous potassium iodate1 gave three spots. Two of these corresponded to adrenaline and noradrenaline (RF = 0.32 and 0.25, respectively) and the third to an unknown adrenaline-like substance (RF = 0.63). Three spots were also detected when development was carried out with the Pauly diazo-reagent or potassium ferricyanide (pH 7.8).

Soluble carbohydrates of fruit plants.

IN the course of an investigation of the organic constituents of fruit plants, the soluble carbohydrates of shoots of apple, plum, etc., have been under investigation by the method of paper chromatography, using as solvents butanol–acetic acid–water (4 : 1 : 5)1, butanol–ethanol–water (4 : 1 : 5)2 and ethyl acetate–acetic acid–water (3 : 1 : 3)3. Whatman's No. 1 and No. 54 filter papers were employed. Spots on the paper chromatograms due to carbohydrates were revealed by using the reagents described by Partridge1,2,4. Examination of the papers after spraying was carried out both in ultra-violet light and daylight, the ultra-violet light being particularly useful in revealing weak spots after treatment with aniline-phthalic acid. For the detection of sorbitol a further reagent described below was employed.