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Evaluation of electrophoresis diagrams.
1960
Abstracts
Section
A 139
]4541 COULOMETRIC MICRO-DETERMINATION OF BROMURAL (a-BROMISOVALERYLUREA) AND CABROMAL (a-BROM-DIETHYLACETYLUREA). K.Kalinowski. (Dept. of Pharmaceutical Chemistry, Academy of Medicine, LBdf, Poland.) Acta Pharm. Polon. ~ 16 (1959) 225. Bromural (BM) and cabromal (CB) were determined by coulometric titration at constant current by electrolytically generated Ag ions. For determination of 0.1 g of BM or CB, 15 ml of water and 1 ml of 15% NaOH were added to the sample and the flask refluxed on a water bath for 15 min. When the solution had cooled 3-5 ml of 30% hydrogen peroxide was added and gently heated. This solution was acidified with acetic acid adding 6 ml of 10% solution in excess. To the electrolytic cell l/125 of this solution and 28 ml 10% KNoj were added withexclusion of light and Ag ions were generated. The current was of the order of 5 mA. The end-point was determined amperometrically with 3 different indicator electrode systems: (1) with 2 polarized Ag electrodes (200 mV); (2) with Ag and Pt electrodes, polarized with 200 mV; and (3) with a Cu-Ag electrode system without external voltage. In all the systems the results were consistent, the error being less than 1%. Ad. Hu. 14551 COULOMETRIC DETERMINATION OF CYCLOHEXAL AND HEXOBARBITONE. K.Kalinowski and H.Baran. (Dept. of Pharmaceutical Chemistry, Academy of Medicine, L,6dL, Poland.) Acta Pharm. Polon., 16 (1959) 231. acid) (CH) and hexobarbitone Cyclohexal 5 - A1 cyclohexenyl-5-ethylbarbituric acid) (HB) were determined by (N-methyl-5-A i -cyclohexenyl-5-methylbarbituric coulometric titration at constant current with electrolytically generated chlorine. For determination of CH 10 ml of about 0.02% solution of CH was mixed with 10 ml of 10% HCl. In HB determination 10 ml of 5% HCl was used. The end-point was determined by amperometry with 2 polarized Pt electrodes. The error of determination was less than 0.7%. Ad. Hu. See also: [255,272,394].
8. ELECTROPHORESIS I4561 A NEW METHOD FOR STAINING PAPER ELECTROPHEROGRAMS. wa. Biokhimiya, 24 (1959) 127.
M. N. Jegoro-
The paper is stained by means of 0.08% solution of acid-deep-blue in 10% AcOH to eliminate the excess dye; the stained bands are eluted with 0.1 N NaOH and the optical densities at 520 mu read with a calorimeter. The intensities are stable for at least 30 min. Ca. Cas. ]4571 EVALUATION OF ELECTROPHORESIS DIAGRAMS. Sorin M. Idu and Nicolae B. Cucu. Hoppe-Seyler’s Z. physiol. Chem. , 314 (1959) 284. With the aid of a simple algebraic method and of a suitably traced diagram method of Wallner Ulke for measuring areas under electrophoresis diagrams’ been simplified.
the has
A 140
Journal
of Electroanalytical
Chemistry
Special apparatus is not needed and speed and accuracy various fractions are improved. Examples of applications to different cases are given.
Vol. 1
in the evaluation of the
Ca. Cas.
I4581
LARGE-SCALE DENSITY GRADIENT ELECTROPHORESIS. II. A SIMPLE EXPERIMENTAL TECHNIQUE SECURING PERFECTLY STABLE ZONES AND FULL UTILIZATION OF THE SEPARATION CAPACITY OF A DENSITY GRADIENT COLUMN. Harry Svensson and Erkki Valmet. Science Tools, 6 (1959) 13. This technique for creating a density gradient uses a device which couples in series 2 closed mixing chambers, the second of which contains the sample to be fractionated. In this manner it is possible to obtain the initial zone and the whole density column in the same operation; moreover the need for trial runs and for personal skill is avoided. Since it is possible to choose conveniently the initial concentrations, as well as the volumes of the 2 mixing compartments, many experimental needs can be satisfied. The zones in the column are made perfectly stable, thus ensuring that the method can be used for large scale fractionation (samples up to 500 mg can be fractioned into 8 components using a 250 ml column). Equations for obtaining suitabie values for the initial concentrations and for the volumes of the mixing chambers are given. Ca. Cas. [459 1 ELECTROMIGRATION OF IONS ABSORBED BY FILTER PAPER. R. A. Bailey and L. Yoffe. (Radiochemical Laboratory, Dept. of Chemistry, McGill University, Montreal, Canada.) Can. J. Chem., 37 (1959) 1527. The variation with absorbance of the zone mobilities and obstructive factors for a number of inorganic ions has been investigated in acetic acid and in ammonium hydroxide at several concentrations. The results agree with the form of the semi-empirical equation of Crawford and Edward. For a given ion the apparent zone mobility remains fairly constant obstructive factor, defined as papp = free soln mobilitv’ as the concentration of the background electrolyte is changed except in the very dilute region. However, the apparent obstructive factor varies with the ion and the background electrolyte indicating that specific effects which are not considered in the’equation are important. D. S. Ru. [4'331 ELECTROPHORETIC SEPARATION AND QUANTITATIVE DETERMINATION OF DYESTUFFS. S. Krauze and L. Piekarski. (Dept. of Food Investigation, Academy of Medicine, Warsaw, Poland. ) Acta Pharm. Polon. , 16 (1959) 395. Paper electrophoresis was applied for the separation and identification of food dyestuffs in cases where chromatographic separation had been used without success. The apparatus used was very simple. The separated dyestuffs were determined by direct photometry of the paper strips or by elution and subsequent colorimetric determination. Ad. Hu. [46Il HIGH-VOLTAGE PAPER ELECTROPHORESIS OF ORGANIC ACIDS AND DETERMINATION OF MIGRATION RATES. D. Gross. (Tate and Lyle Research Lab. , Keston, Kent, Great Britain.) Chemistry & Industry, (1959) 1219. The electrophoresis ferent conditions:
of 56 organic acids has been carried
out under three dif-
Abstracts
Section
A 139
]4541 COULOMETRIC MICRO-DETERMINATION OF BROMURAL (a-BROMISOVALERYLUREA) AND CABROMAL (a-BROM-DIETHYLACETYLUREA). K.Kalinowski. (Dept. of Pharmaceutical Chemistry, Academy of Medicine, LBdf, Poland.) Acta Pharm. Polon. ~ 16 (1959) 225. Bromural (BM) and cabromal (CB) were determined by coulometric titration at constant current by electrolytically generated Ag ions. For determination of 0.1 g of BM or CB, 15 ml of water and 1 ml of 15% NaOH were added to the sample and the flask refluxed on a water bath for 15 min. When the solution had cooled 3-5 ml of 30% hydrogen peroxide was added and gently heated. This solution was acidified with acetic acid adding 6 ml of 10% solution in excess. To the electrolytic cell l/125 of this solution and 28 ml 10% KNoj were added withexclusion of light and Ag ions were generated. The current was of the order of 5 mA. The end-point was determined amperometrically with 3 different indicator electrode systems: (1) with 2 polarized Ag electrodes (200 mV); (2) with Ag and Pt electrodes, polarized with 200 mV; and (3) with a Cu-Ag electrode system without external voltage. In all the systems the results were consistent, the error being less than 1%. Ad. Hu. 14551 COULOMETRIC DETERMINATION OF CYCLOHEXAL AND HEXOBARBITONE. K.Kalinowski and H.Baran. (Dept. of Pharmaceutical Chemistry, Academy of Medicine, L,6dL, Poland.) Acta Pharm. Polon., 16 (1959) 231. acid) (CH) and hexobarbitone Cyclohexal 5 - A1 cyclohexenyl-5-ethylbarbituric acid) (HB) were determined by (N-methyl-5-A i -cyclohexenyl-5-methylbarbituric coulometric titration at constant current with electrolytically generated chlorine. For determination of CH 10 ml of about 0.02% solution of CH was mixed with 10 ml of 10% HCl. In HB determination 10 ml of 5% HCl was used. The end-point was determined by amperometry with 2 polarized Pt electrodes. The error of determination was less than 0.7%. Ad. Hu. See also: [255,272,394].
8. ELECTROPHORESIS I4561 A NEW METHOD FOR STAINING PAPER ELECTROPHEROGRAMS. wa. Biokhimiya, 24 (1959) 127.
M. N. Jegoro-
The paper is stained by means of 0.08% solution of acid-deep-blue in 10% AcOH to eliminate the excess dye; the stained bands are eluted with 0.1 N NaOH and the optical densities at 520 mu read with a calorimeter. The intensities are stable for at least 30 min. Ca. Cas. ]4571 EVALUATION OF ELECTROPHORESIS DIAGRAMS. Sorin M. Idu and Nicolae B. Cucu. Hoppe-Seyler’s Z. physiol. Chem. , 314 (1959) 284. With the aid of a simple algebraic method and of a suitably traced diagram method of Wallner Ulke for measuring areas under electrophoresis diagrams’ been simplified.
the has
A 140
Journal
of Electroanalytical
Chemistry
Special apparatus is not needed and speed and accuracy various fractions are improved. Examples of applications to different cases are given.
Vol. 1
in the evaluation of the
Ca. Cas.
I4581
LARGE-SCALE DENSITY GRADIENT ELECTROPHORESIS. II. A SIMPLE EXPERIMENTAL TECHNIQUE SECURING PERFECTLY STABLE ZONES AND FULL UTILIZATION OF THE SEPARATION CAPACITY OF A DENSITY GRADIENT COLUMN. Harry Svensson and Erkki Valmet. Science Tools, 6 (1959) 13. This technique for creating a density gradient uses a device which couples in series 2 closed mixing chambers, the second of which contains the sample to be fractionated. In this manner it is possible to obtain the initial zone and the whole density column in the same operation; moreover the need for trial runs and for personal skill is avoided. Since it is possible to choose conveniently the initial concentrations, as well as the volumes of the 2 mixing compartments, many experimental needs can be satisfied. The zones in the column are made perfectly stable, thus ensuring that the method can be used for large scale fractionation (samples up to 500 mg can be fractioned into 8 components using a 250 ml column). Equations for obtaining suitabie values for the initial concentrations and for the volumes of the mixing chambers are given. Ca. Cas. [459 1 ELECTROMIGRATION OF IONS ABSORBED BY FILTER PAPER. R. A. Bailey and L. Yoffe. (Radiochemical Laboratory, Dept. of Chemistry, McGill University, Montreal, Canada.) Can. J. Chem., 37 (1959) 1527. The variation with absorbance of the zone mobilities and obstructive factors for a number of inorganic ions has been investigated in acetic acid and in ammonium hydroxide at several concentrations. The results agree with the form of the semi-empirical equation of Crawford and Edward. For a given ion the apparent zone mobility remains fairly constant obstructive factor, defined as papp = free soln mobilitv’ as the concentration of the background electrolyte is changed except in the very dilute region. However, the apparent obstructive factor varies with the ion and the background electrolyte indicating that specific effects which are not considered in the’equation are important. D. S. Ru. [4'331 ELECTROPHORETIC SEPARATION AND QUANTITATIVE DETERMINATION OF DYESTUFFS. S. Krauze and L. Piekarski. (Dept. of Food Investigation, Academy of Medicine, Warsaw, Poland. ) Acta Pharm. Polon. , 16 (1959) 395. Paper electrophoresis was applied for the separation and identification of food dyestuffs in cases where chromatographic separation had been used without success. The apparatus used was very simple. The separated dyestuffs were determined by direct photometry of the paper strips or by elution and subsequent colorimetric determination. Ad. Hu. [46Il HIGH-VOLTAGE PAPER ELECTROPHORESIS OF ORGANIC ACIDS AND DETERMINATION OF MIGRATION RATES. D. Gross. (Tate and Lyle Research Lab. , Keston, Kent, Great Britain.) Chemistry & Industry, (1959) 1219. The electrophoresis ferent conditions:
of 56 organic acids has been carried
out under three dif-