THE STANDARDIZATION OF COMMERCIAL BISMUTH TRIBROMPHENATE

William Rabak, Ph.G., Sc.B.

This work was begun in view of a request received by the Council on Pharmacy and Chemistry from the Medical Section of the Council of National Defense for a report on the quality of bismuth tri­brom­phenate, offered to the government by a certain firm.

In submitting a specimen of its product, “Bismuth Tri­brom­phenolate,” the firm claimed that “it is of high character, matching exactly the German product formerly imported into this country,” and expressed the belief that it would be found to conform to the standards for this preparation in New and Non­official Remedies. Later a second specimen was received from the same company, with the request that this be substituted for that first received. It was explained that the first had been taken from an experimental lot, and that the second, taken from the regular factory output, was identical with the first except that it was free from odor because of the more thorough washing to which it had been subjected. Accordingly, the examination which is reported below refers to the second specimen only.

New and Non­official Remedies, 1918, defines bismuth tri­brom­phenate as basis bismuth tri­brom­phenate having the formula Bi(C6H2Br3O)2OH.Bi2O3, and it is required to yield not less than 49.5 per cent. of bismuth oxid (the chemical formula requires 46.2 per cent. bismuth, or 51.6 per cent. bismuth oxid, Bi2O3, and 49.2 per cent. tri­brom­phenate, C6H2Br3.OH). It describes it as a “fine, yellow, nearly odorless and tasteless powder, neutral in reaction,” and “only slightly soluble in water, alcohol, chloroform, liquid petrolatum and vegetable oils.” It is required to yield tri­brom­phenol (to which a melting point of 95 C. is assigned) when decomposed by alkali and the alkali tri­brom­phenate decomposed by acid, the separated tri­brom­phenol purified and dried.

As the New and Non­official Remedies description appeared loosely drawn—it had been based on information furnished for the product Xeroform when this, because of patent protection, was the only bismuth tri­brom­phenate on the market—it was decided to include in the examination also specimens of the two brands of Bismuth Tri­brom­phenate included in New and Non­official Remedies, namely, Bismuth Tri­brom­phenate-Merck (Merck and Company) and Xeroform-Heyden (The Heyden Chemical Works). The Merck specimen had been received by the Council from Merck and Company in 1915, while the Heyden preparation was obtained direct from the firm’s Chicago branch in April, 1918. At this time Bismuth Tri­brom­phenate-Merck could not be obtained from the Chicago wholesale houses.

All three specimens were nearly odorless. Two of the specimens (the Research Council Specimen and Merck products) were of a lemon-yellow color, while the Heyden preparation was of a grayish color.

BISMUTH DETERMINATION

Four methods for the determination of the bismuth content of the specimens were tried: