Action and use
Antiseptic; antimicrobial preservative; antipruritic.
When Phenol is to be mixed with collodion, fixed oils or paraffins, melted Phenol should be used and not Liquefied Phenol.
DEFINITION
Liquefied Phenol contains not less than 77.0% and not more than 81.5% w/w of Phenol in Purified Water. It is prepared by adding Purified Water to melted Phenol.
CHARACTERISTICS
A colourless or faintly coloured liquid; caustic.
Soluble in water; miscible with ethanol (96%), with ether and with glycerol.
IDENTIFICATION
A. Dissolve 0.6 g in 2 mL of 13.5M ammonia and dilute to 100 mL with water. To 2 mL of the resulting solution add 0.05 mL of sodium hypochlorite solution. A blue colour is produced which becomes
progressively more intense.
B. Dilute 1 mL of a 15% w/v solution to 10 mL and add 0.1 mL of iron(III) chloride solution R1. A violet colour is produced which is discharged on the addition of propan-2-ol.
C. To 1 mL of a 15% w/v solution add 10 mL of water and 1 mL of bromine water. A white or yellowish white precipitate is produced.
TESTS
Acidity
To 2 mL of a 15% w/v solution add 0.05 mL of methyl orange solution. The solution is yellow.
Clarity and colour of solution
A solution of 1.0 mL in 14 mL of water, at 20°, is clear, Appendix IV A, and not more intensely coloured than reference solution R7
or B7, Appendix IV B, Method II.
Weight per mL
1.055 to 1.060 g, Appendix V G.
Non-volatile matter
When heated on a water bath and dried at 105°, leaves not more than 0.05% w/v of residue.
ASSAY
Dissolve 2.5 g in sufficient water to produce 1000 mL, transfer 25 mL to a 500 mL glass-stoppered flask and add 50 mL of 0.05M bromine VS and 5 mL of hydrochloric acid, stopper, swirl occasionally over a period of 30 minutes and allow to stand for 15 minutes. Add 5 mL of a 20% w/v solution of potassium iodide taking care to avoid loss of bromine, shake thoroughly and titrate with 0.1M sodium thiosulfate VS until only a faint yellow colour remains. Add 0.1 mL of starch mucilage and 10 mL of chloroform and complete the titration with vigorous shaking. Repeat the operation without the material being examined. The difference between the titrations represents the amount of bromine required. Each mL of 0.05M bromine VS is equivalent to 1.569 mg of C6H6O.
STORAGE
Liquefied Phenol should be protected from light. Liquefied Phenol may congeal or deposit crystals if stored at a temperature below 4°. It should be completely melted before use.
LABELLING
The label states ‘contains 80% phenol’.
