Heat gently a mixture of about 0.2 gm. of bismuth tribromphenate with 5 c.c. of potassium hydroxide test solution and about 0.2 gm. of aluminum wire; the vapors evolved do not turn red litmus blue (nitrates).
Shake 1 gm. of bismuth tribromphenate frequently during fifteen minutes with 30 c.c. of alcohol (95 per cent.), filter and rinse flask with two separate 10 c.c. portions of alcohol, allowing the washings to run through filter. To the combined filtrate and washings add 20 c.c. of tenth-normal sodium hydroxide and a few drops of phenolphthalein solution and determine the excess of alkali with tenth-normal hydrochloric acid. Not more than 1 c.c. of tenth-normal sodium hydroxide should have been consumed by the alcoholic liquid (free tribromphenol).
Add 2 c.c. of nitric acid to 2 gm. of bismuth tribromphenate in a porcelain crucible, carefully evaporate to dryness on a sand bath and incinerate. Dissolve the residue in 5 c.c. of concentrated hydrochloric acid and add to the solution 10 c.c. of a saturated solution of stannous chloride in concentrated hydrochloric acid. The mixture should not darken on standing thirty minutes (arsenic).
Mix 0.5 gm. of the salt with 10 c.c. of a mixture of equal parts of hydrochloric acid, U. S. P., and distilled water. No effervescence should occur (carbonate).
To about 0.5 gm. of bismuth tribromphenate, accurately weighed, add 20 c.c. of hydrochloric acid and digest on water bath. Add 150 c.c. of distilled water and filter. Rinse the beaker with 30 c.c. of distilled water and allow the washings to run through the filter. Saturate the combined filtrate and washings with hydrogen sulphide, filter off the bismuth sulphide, wash and dissolve in hot dilute nitric acid. Add a slight excess of ammonia water followed by 2 c.c. of ammonium carbonate test solution. Allow to stand thirty minutes, filter off the precipitated bismuth hydroxide and heat to constant weight at dull red heat. The residue of bismuth oxide (Bi2O3) should not be less than 45 per cent. nor more than 55 per cent. of the original weight of bismuth tribromphenate taken, corresponding to not less than 40 per cent. nor more than 49 per cent. of bismuth.
The Heyden Chemical Works accepted the proposed monograph. Regarding the Laboratory’s findings, the firm stated that “the product had to be made in this country after importations from Europe became impossible and the first lots were not fully up to the standard.” Later the firm stated that it could furnish a product which it considered equal to that which was previously imported and offered to submit “samples of the new material.”
Merck and Co. acknowledged the receipt of the monograph but made no statement as to its acceptance or suggestions for its revision. As the new monograph was accepted by the Heyden Chemical Works and as Merck and Co. offered no objections, it was adopted for N. N. R., 1919, by the Council on Pharmacy and Chemistry.
In November, 1918, Merck and Co. sent a specimen labeled “Bismuth Tribromphenate-Merck,” “Merck and Co., New York, Distributors and Guarantors” and wrote: “You will notice this sample conforms in nearly all details to the tests submitted with our letter of June 4. We have been able to produce better goods, but just at present unsatisfactory starting material confronts us.”
Examination of the specimen demonstrated that it was soluble to a considerable extent in alcohol (the N. N. R., 1918, description provides that it should be only slightly soluble in alcohol) and, according to the standards adopted for New and Nonofficial Remedies, 1919, contained 18 per cent. of uncombined tribromphenol (more than five times the permitted amount).