 Description : |
| Clear, colourless or pale yellow liquid when freshly distilled, becoming darker and thicker by ageing or exposure to air; odour as of clove. |
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| Solubility : Freely soluble in ethanol (70%). |
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| STANDARDS : |
| Clove Oil contains not less than 85.0 per cent w/w and not more than 95.0 per cent w/w of phenolic substances, chiefly eugenol, C10H12O2. |
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| Identification : |
| Shake 1 ml with 20 ml of hot water; the mixture shows not more than a scarcely perceptible acid reaction with blue litmus paper. Cool the mixture, pass the aqueous layer through a wetted filter and treat the clear filtrate with 1 drop of ferric chloride test solution. The mixture has only a transient greyish-green colour but not a blue or violet colour. |
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| Specific gravity : Between 1.047 and 1.060 |
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| Optical rotation : Between 0o and –1.5o |
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| Refractive index : Between 1.528 and 1.537, determined at 20o. |
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| Heavy metals : Not more than 40 ppm. |
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| Alkali-soluble matter : |
| Place 80 ml of a 5% w/v solution of potassium hydroxide in a 150-ml flask with a long neck which is graduated in tenths of a ml and is of such a diameter that not less than 15 cm in length has a capacity of 10 ml. Clean the flask with sulphuric acid and rinse well with water before use. Add 10 ml of the oil and shake thoroughly at 5-minute intervals for 30 minutes at ambient temperature. Raise the undissolved portion of the oil into the graduated part of the neck of the flask by the gradual addition of more of the potassium hydroxide solution; allow to stand for not less than 24 hours and read off the volume of the undissolved portion of the oil which measures between 1.0 and 1.5 ml. |
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| Assay : |
| Carry out the method for gas chromatography, using the following solutions in ethanol (95%) containing (1) 0.20% w/v of the oil being examined, (2) 0.20% w/v of the oil being examined and 0.15% w/v of 1-decanol (internal standard) and (3) 0.20% w/v of eugenol and 0.15% w/v of the internal standard. |
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| The chromatographic procedure may be carried out using a glass column (1.5 m x 4 mm) packed with 3% w/w of dimethyl silicone fluid (OV-101 is suitable) on acid-washed diatomaceous support (120 mesh) at a temperature maintained at 110o for 18 minutes, then increased to 170o at a rate of 12o per minute and maintained at this temperature for 2 minutes and inlet port at 220o, the detector at 300o and flow rate of 40 ml per minute of the carrier gas. |
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| Calculate the eugenol content in the oil being examined using the ratios of the area of the peak corresponding to eugenol to the area of the peak due to the internal standard in the chromatogram obtained with solutions (2) and (3). |
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| Therapeutic action : |
| Useful in thirst, morning sickness, gingivitis, pain due to Kapha dosh |
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