§ 21.124. Quassin.
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/us/cfr/t27/s§ 21.124·A research copy — for the controlling text, always check the official state or federal source. Not legal advice.
(a)Quassin is the bitter principle of quassia wood (occurring as a mixture of two isomeric forms). It shall be a good commercial grade of purified amorphous quassin, standardized as to bitterness.
(b)Bitterness. An aqueous solution of quassin shall be distinctly bitter at a 1 to 250,000 dilution. To test: Dissolve 0.1 gram of quassin in 100 mL of 95 percent alcohol, then dilute 4 mL of the solution to 1,000 mL with distilled water, mix well and taste.
(c)Identification test. Dissolve about 0.5 gram of quassin in 10 mL of 95 percent alcohol and filter. To 5 mL of the filtrate, add 5 mL of concentrated hydrochloric acid and 1 mg of phloroglucinol and mix well. A red color develops.
(d)Optical assay. When 1 gram of quassin (in solution in a small amount of 95 percent alcohol) is dissolved in 10,000 mL of water, the absorbance of the solution in a 1 cm cell at a wavelength of 258 millimicrons shall not be less than 0.400.
(e)Solubility. When 0.5 gram of quassin is added to 25 mL of 190 proof alcohol, it shall dissolve completely. \[T.D. ATF-133, 48 FR 24673, June 2, 1983. Redesignated by T.D. ATF-442, 66 FR 12854, Mar. 1, 2001\]