| Description |
Colourless, hexagonal or needle-like crystals, or infused masses or a crystalline powder; has a pleasant peppermint-like odour
|
Solubility |
Very soluble in ethanol (95%) and in ether; freely soluble in light liquid paraffin, in glacial acetic acid and in volatile oils, slightly soluble in water
|
| Identification |
-
|
Identification 'A' |
The spectrum of sample should be concordant with spectrum of standard
|
| Identification 'B' |
The colour should changes to violet (Distinction from thymol)
|
Identification 'C' |
The principal peak in the chromatogram obtained with the test solution corresponds to the peak in the chromatogram obtained with the reference solution
|
| Appearance of solution |
The solution is not more opalescent than opalescence standard OS4, and not more intensely coloured than reference solution RS6
|
Acidity |
The solution should be yellow
|
| Specific optical rotation |
For (-)-menthol -49.0° to -51.0°,For (± )-menthol -2.0 °to +2.0°
|
Congealing range of (± )menthol |
27.0° to 28.0°
|
| Melting range of (-)-menthol |
41.0° to 44.0°
|
Related Substances |
-
|
| Total impurities |
NMT 2.0%
|
Readily oxidisable substances in (+) menthol |
The purple colour of potassium permanganate should be apparent after 5 minutes
|