» Storax is a balsam obtained from the trunk of Liquidambar orientalis Miller, known in commerce as Levant Storax, or of Liquidambar styraciflua Linné, known in commerce as American Storax (Fam. Hamamelidaceae).
Packaging and storage— Preserve in well-closed containers.
Loss on drying 731 Dry about 2 g, accurately weighed, at 105 for 2 hours: it loses not more than 20.0% of its weight.
Alcohol-insoluble substances— Accurately weigh about 10 g of mixed Storax in a beaker, heat at 105 for 30 minutes, take up the residue in 100 mL of hot alcohol, filter through counter-balanced filters or a tared filter crucible, and wash the residue with small portions of hot alcohol until the last washing is colorless or practically so: the weight of the residue so obtained, after drying at 105 for 1 hour, does not exceed 5.0% of the weight of Storax taken.
Alcohol-soluble substances— Evaporate the combined alcohol filtrate and washings obtained in the test for Alcohol-insoluble substances at a temperature not exceeding 60, and dry the residue at 105 for 1 hour: the weight of the yellow to brown residue of purified Storax so obtained is not less than 70.0% of the weight of the Storax taken.
Acid value, Saponification value, Cinnamic acid— The purified Storax obtained in the test for Alcohol-soluble substances meets the requirements of the following tests.
Acid value 401 —Dissolve about 1 g of the purified Storax, accurately weighed, in 50 mL of neutralized alcohol, add 0.5 mL of phenolphthalein TS, and titrate with 0.5 N sodium hydroxide VS: the acid value is between 50 and 85 for Levant Storax and between 36 and 85 for American Storax.
Saponification value 401 —Place about 2 g of the purified Storax, accurately weighed, in a 250-mL flask, mix it with 50 mL of solvent hexane, add 25.0 mL of 0.5 N alcoholic potassium hydroxide VS, and allow the mixture to stand for 24 hours with frequent agitation. Then add 0.5 mL of phenolphthalein TS, and titrate the excess alkali with 0.5 N hydrochloric acid VS: the saponification value thus determined is between 160 and 200.
Cinnamic acid— Add about 2 g of the purified Storax, accurately weighed, to 25 mL of 0.5 N alcoholic potassium hydroxide, and boil the mixture for 1 hour under a reflux condenser. Add 0.5 mL of phenolphthalein TS, neutralize with 0.5 N sulfuric acid, and evaporate the alcohol on a steam bath. Dissolve the residue in 50 mL of water, and shake the solution with 20 mL of ether. Shake the separated ether with 5 mL of water, adding the washing to the water solution, and reject the ether extract. Add to the water solution 10 mL of diluted sulfuric acid, and shake with four 20-mL portions of ether. Wash the combined ether extracts with 5 mL of water, rejecting the water washing, transfer to a flask, and distill off the ether. Add to the residue 100 mL of water, and boil the mixture vigorously for 15 minutes under a reflux condenser. Filter while hot, and allow the filtrate to cool to about 25: white crystals of cinnamic acid separate. Collect and dry the cinnamic acid by vacuum filtration. Repeat the extraction of the residue twice by boiling each time under a reflux condenser, as previously described, with the filtrate from the preceding crystallization, and collect the additional cinnamic acid in the same crucible. Finally wash the cinnamic acid with two 10-mL portions of ice-cold water, dry at 80, and weigh. The weight of the cinnamic acid so obtained is not less than 25.0% of the weight of purified Storax taken. A portion of the acid recrystallized from hot water melts between 134 and 135.
To about 50 mg of the cinnamic acid obtained as directed above add 5 mL of 2 N sulfuric acid, heat, and add potassium permanganate TS: the odor of benzaldehyde is perceptible.
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Monograph Maged H. Sharaf, Ph.D.
Senior Scientist
(DSB05) Dietary Supplements - Botanicals
USP32–NF27 Page 3601
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.