| No. |
TESTS |
REQUIREMENTS |
1 |
Description |
Clear, colourless melted solid or milky paste having pure peppermint like odour. |
2 |
Solubility |
Very soluble in ethanol (70%) and ether, freely soluble in light liquid paraffin, in glacial acetic acid and in volatile oils. slightly soluble in water. |
3 |
Identification
by chemical |
Reaction with sulphuric acid and with the addition of solution of vanillin in sulphuric acid should produce orange colour. Further addition of water should change the colour to violet.
|
4 |
Specific optical rotation
(10% w/v soln. in ethanol 95%) |
Between -47.0°to -51.0°
-47.0°- 51.0° |
5 |
melting range |
Between 38℃to 42℃
38℃ - 42℃ |
6 |
Purity(by GC)
L-menthol
Total menthol
|
Not less than 96.0%
Not less than 97.0%
|
7 |
Residue on evaporation |
Not more than 0.05% w/w |
No. |
TESTS |
REQUIREMENTS |
1 |
Description |
Colourless, fine powder or infused masses or crystalline powder, odour, pleasant and characteristic. |
2 |
Solubility |
Very soluble in ethanol(95%) and ether, freely soluble in light liquid paraffin, in glacial acetic acid and in volatile oils. slightly soluble in water. |
3 |
Identification
(1)by IR
(2)by chemical
|
The IR absorption spectrum is concordant with the reference spectrum of menthol or with the spectrum obtained from menthol RS.
a. Dissolve 10mg in 1ml of sulfuric acid and add 1ml of 1% w/v soln of vanillin in sulfuric acid, and orange yellow colour is produce. Add 1ml of water, the coulour change to violet.(distinction from thymol.)
b. When triturated with about an equal weight or camphor or chloral hydrate or phenol the mixture liquefies.
c. Melt between 41℃and 44℃
|
4 |
Specific optical rotation
(10% w/v soln. in ethanol 95%) |
Between -49.0°to -51.0° |
5 |
Congealing range |
Between 27℃to 28℃
27℃ -28℃ |
6 |
Acidity |
Should comply |
7 |
Clarity and colour of solution |
Should comply |
8 |
Related substance
a. Single highest
b. impurity
Total impurity |
Not more than 0.01%
Not mare than 1.00% |
9 |
Residue on evaporation |
Not more than 0.05% w/w |