Determination of Organic Substances by Standard Chromous Chloride Solution

Abstract A method is given for the quantitative determination of sodium lauryl sulfate in liquid, frozen, powdered, or flake-dried egg white. The egg white is dissolved in water and the protein is precipitated with ethanol and filtered off. The filtrate is evaporated, the residue is dissolved in water, and the pH is adjusted to 5.0. Total alkyl sulfates are titrated with standard benzethonium chloride solution in the presence of chloroform with bromphenol blue indicator. Results are calculated as sodium lauryl sulfate. The formation of the bromphenol bluebenzethonium chloride complex, when excess benzethonium chloride is present, is taken as the end point. The blue-green complex is soluble in the chloroform. Overall recoveries of sodium lauryl sulfate from egg whites ranged from 94 to 100%. Collaborative study of the method is recommended.

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Determination of free acid in ferric chloride solution (reivestigation of JIS K 1447).

BUNSEKI KAGAKU ◽

10.2116/bunsekikagaku.41.3_t45 ◽

1992 ◽

Vol 41 (3) ◽

pp. T45-T47 ◽

Cited By ~ 1

Author(s):

Masanobu SAHARA ◽

Hirotoshi YOSHIMURA ◽

Fumio SAGARA ◽

Keihei UFAO ◽

Isao YOSHIDA ◽

...

Keyword(s):

Ferric Chloride ◽

Chloride Solution ◽

Free Acid ◽

Ferric Chloride Solution

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DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

Canadian Journal of Chemistry ◽

10.1139/v60-208 ◽

1960 ◽

Vol 38 (9) ◽

pp. 1488-1494 ◽

Cited By ~ 6

Author(s):

E. J. Bounsall ◽

W. A. E. McBryde

Keyword(s):

Aqueous Solution ◽

Nitric Acid ◽

Sodium Chloride ◽

Hydrochloric Acid ◽

Chloride Solution ◽

Sodium Chloride Solution ◽

Silver Content ◽

Aqueous Sodium Chloride Solution ◽

Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

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The Perchloric Method for the Determination of Sulfur in Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3548048 ◽

1934 ◽

Vol 7 (4) ◽

pp. 730-735

Author(s):

Ernest Kahane

Keyword(s):

Nitric Acid ◽

Perchloric Acid ◽

Organic Substance ◽

Present Author ◽

General Idea ◽

Organic Substances ◽

Gutta Percha ◽

Higher Temperature ◽

As If

Abstract The problem of the determination of sulfur in rubber has been dealt with extensively in the literature, and it seems as if discussions and descriptions of new technic are nowhere nearly ended yet. The determination is so essential, and its rapid and precise execution is of such importance in industrial technic, that efforts in this direction should not be regarded as wasted. In 1926 and in 1927 Le Caoutchouc et La Gutta-Percha contained two articles in which the present author discussed the conditions of the determination of sulfur in rubber and then proposed the use of a new oxidizing mixture, not mentioned previous to that time, which involved the destruction of organic substances by perchloric acid. This method consisted simply in the attack on a 1-gram sample of rubber by 10 cc. of nitric acid (d. 1.39) and 5 cc. of perchloric acid (d. 1.61). Upon heating, attack by the nitric acid takes place, and this is followed by evaporation of the excess nitric acid, then at a little higher temperature there is an attack by the perchloric acid, which oxidizes the rest of the organic substance completely. This publication was concerned much more, in the determination of sulfur by the perchloric method, with the general idea of the destruction of organic substances than it was with the precise details of carrying it out. The technic had been studied somewhat superficially, as is shown by the text of the article itself.

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