Ph Eur
C8H8O3 -- 152.1 -- 119-36-860-7
Action and use: Counter-irritant.
DEFINITION
Methyl 2-hydroxybenzoate.
Content: 99.0 per cent m/m to 100.5 per cent m/m.
CHARACTERS
Appearance: Colourless or slightly yellow liquid.
Solubility: Very slightly soluble in water, miscible with ethanol (96 per cent) and with fatty and essential oils.
IDENTIFICATION
A. Heat 0.25 ml with 2 ml of dilute sodium hydroxide solution on a water-bath for 5 min. Add 3 ml of dilute sulphuric acid. A crystalline precipitate is formed. Filter. The precipitate washed with water and dried at 100C-105C, melts at 156C to 161C.
B. To 10 ml of a saturated solution add 0.05 ml of ferric chloride solution. A violet colour develops.
TESTS
Appearance of solution: The solution is clear and not more intensely coloured than reference solution.
To 2 ml add 10 ml of ethanol (96 per cent).
Acidity: Dissolve 5.0 g in a mixture of 0.2 ml of bromocresol green solution and 50 ml of ethanol (96 per cent) previously neutralised to a blue colour by addition of 0.1 M sodium hydroxide. Not more than 0.4 ml of 0.1 M sodium hydroxide is required to restore the blue colour.
Relative density: 1.180 to 1.186.
Refractive index: 1.535 to 1.538.
ASSAY
Dissolve 0.500 g in 25 ml of ethanol (96 per cent). Add 0.05 ml of phenol red solution and neutralise with 0.1 M sodium hydroxide. To the neutralised solution add 50.0 ml of 0.1 M sodium hydroxide and heat under a reflux condenser on a water-bath for 30 min. Cool and titrate with 0.1 M hydrochloric acid . Calculate the volume of 0.1 M sodium hydroxide used in the saponification. Carry out a blank titration.
1 ml of 0.1 M sodium hydroxide is equivalent to 15.21 mg of C8H8O3.
C8H8O3 -- 152.15 --- 119-36-8
Benzoic acid, 2-hydroxy-, methyl ester.
Methyl Salicylate is produced synthetically or is obtained by maceration and subsequent distillation with steam from the leaves of Gaultheria procumbens Linné (Fam. Ericaceae) or from the bark of Betula lenta Linné (Fam. Betulaceae). It contains not less than 98.0 percent and not more than 100.5 percent of C8H8O3.
Labeling: Label it to indicate whether it was made synthetically or distilled from either of the plants mentioned above.
Solubility in 70 percent alcohol: One volume of synthetic Methyl Salicylate dissolves in 7 volumes of 70 percent alcohol. One volume of natural Methyl Salicylate dissolves in 7 volumes of 70 percent alcohol, the solution having not more than a slight cloudiness.
Identification: Shake 1 drop with about 5 mL of water, and add 1 drop of ferric chloride: the resulting mixture has a deep violet color.
Specific gravity: between 1.180 and 1.185 for the synthetic variety; between 1.176 and 1.182 for the natural variety.
Angular rotation: Synthetic Methyl Salicylate and that from betula are optically inactive. Methyl Salicylate from gaultheria is slightly levorotatory, the angular rotation not exceeding 1.5 degree in a 100-mm tube.
Refractive index: between 1.535 and 1.538 at 20 .
Heavy metals: 20 microgm per g.
Assay: Place about 2 g of Methyl Salicylate, accurately weighed, in a flask, add 40.0 mL of 1 N sodium hydroxide and boil gently under a reflux condenser for 2 hours. Cool, rinse the condenser and the sides of the flask with a few mL of water, add PhPh and titrate the excess alkali with 1 N sulfuric acid. Perform a blank. Each mL of 1 N sodium hydroxide corresponds to 152.2 mg of C8H8O3.
Methyl Salicylate IP Grade is also offered.
Gaultheria Oil
CAS: [68917-75-9]
DESCRIPTION
Wintergreen Oil occurs as a colorless to yellow liquid withthe characteristic odor and taste of wintergreen. It is obtained by maceration and subsequent distillation with steam from the leaves of Gualtheria procumbens L. (Fam. Ericaceae) or from the bark of Betula lenta L. (Fam. Betulaceae). It boils, with decomposition, between 219C and 224C. It is soluble in alcohol and in glacial acetic acid, and it is very slightly soluble in water.
Function: Flavoring agent.
REQUIREMENTS
Identification:-
A. Shake 1 drop of sample with about 5 mL of water, and add 1 drop of ferric chloride. A deep violet color appears.
B. The infrared absorption spectrum of the sample exhibits relative maxima at the same wavelengths as those of a typical spectrum as shown in the section on Infrared Spectra, using the same test conditions as specified therein.
Assay: Not less than 98.0% and not more than 100.5% of methyl salicylate (C8H8O3).
Acid Value: Not more than 1.0.
Angular Rotation: Slightly levorotatory, exhibiting a rotation of not more than 1.5°.
Refractive Index: Between 1.535 and 1.538 at 20C.
Solubility in Alcohol: Passes test.
Specific Gravity: Between 1.176 and 1.182.
