Alcohol Specifications

United Kingdom

British Pharmacopoeia (B.P.) January 1999

1. Ethanol (96 per cent)

 

Ethanol (96 percent) complies with the requirements of the 3rd edition of the European Pharmacopoeia, as set out below:

 

(1) Definition: Ethanol (96 per cent) contains not less than 95.1 percent v/v (92.6 per cent m/m) and not more than 96.9 percent v/v (95.2 per cent m/m) of C2H5OH (MW:46.07) at 20C, and water.
(2) Characteristics: (a)  A colorless, clear, volatile, flammable liquid, hygroscopic, miscible with water and with methylene chloride. It burns with a blue, smokeless flame.
   

(b)

 It boils at about 78C.
(3) Identification:

(a)

Relative density: 0.8051 to 0.8124
    (b)  Mix 0.1 ml with 1 ml of a 10g/l solution of potassium permanganate R and 0.2 ml of dilute sulphuric acid R in a test-tube. Cover immediately with a filter paper moistened with a freshly prepared solution containing 0.1 g of sodium nitroprusside R and 0.5 g of piperazine hydrate R in 5 ml of water R. After a few minutes, an intense blue color appears on the paper and becomes paler after 10 to 15 minutes.
    (c)  To 0.5 ml add 5 ml of water R, 2 ml of dilute sodium hydroxide solution R, then slowly add 2 ml of 0.05 M Iodine. A yellow precipitate is formed within 30 minutes.
(4) Tests: (a) Acidity or alkalinity: To 20 ml add 20 ml of carbon dioxide-free water R and 0.1 ml of phenolphthalein solution R. The solution is colorless. Add 1.0 ml of 0.01 M sodium hydroxide. The solution is pink (30 p.p.m, expressed as acetic acid).
    (b) Ultra violet absorbance: Not more than 0.40 at 240nm, 0.30 between 250 and 260 nm, and 0.10 between 270 and 340 nm. The absorption curve is smooth.
    c)  Volatile impurities: Examine by gas chromatography.

(i) Aldehydes: The total of acetaldehyde and acetal is not greater than 10 p.p.m (v/v) expressed as acetaldehyde.
(ii) Benzene: Not more than 2 p.p.m v/v
    (d) Residue on evaporation: Not more than 25 p.p.m (w/v)

Note: Reference should  be made to the original specification for details of the test procedures.


 

2. Anhydrous Ethanol ("Absolute Alcohol" or "Dehydrated Alcohol")

This product complies with the requirements of the 3rd edition of the European Pharmacopoeia, as set out below:

(1) Definition: Anhydrous ethanol contains not less than 99.5 % v/v of C2H5OH, at 20C
(2) Characteristics: (a)  A colorless, clear, volatile, flammable liquid, hygroscopic, miscible with water and with methylene chloride. It burns with a blue, smokeless flame
   

(b)

 It boils at about 78C
(3) Identification:

(a)

Relative density: 0.7907 to 0.7932
    (b)  Mix 0.1 ml with 1 ml of a 10g/l solution of potassium permanganate R and 0.2 ml of dilute sulphuric acid R in a test-tube. Cover immediately with a filter paper moistened with a freshly prepared solution containing 0.1 g of sodium nitroprusside R and 0.5 g of piperazine hydrate R in 5 ml of water R. After a few minutes, an intense blue color appears on the paper and becomes paler after 10 to 15 minutes.
    (c)  To 0.5 ml add 5 ml of water R, 2 ml of dilute sodium hydroxide solution R, then slowly add 2 ml of 0.05 M Iodine. A yellow precipitate is formed within 30 minutes.
(4) Tests: (a) Acidity or alkalinity: To 20 ml add 20 ml of carbon dioxide-free water R and 0.1 ml of phenolphthalein solution R. The solution is colorless. Add 1.0 ml of 0.01 M sodium hydroxide. The solution is pink (30 p.p.m, expressed as acetic acid).
    (b) Ultra violet absorbance: Not more than 0.40 at 240nm, 0.30 between 250 and 260 nm, and 0.10 between 270 and 340 nm. The absorption curve is smooth.
    c)  Volatile impurities: Examine by gas chromatography.

(i) Aldehydes: The total of acetaldehyde and acetal is not greater than 10 p.p.m (v/v) expressed as acetaldehyde.
(ii) Benzene: Not more than 2 p.p.m v/v
    (d) Residue on evaporation: Not more than 25 p.p.m (w/v)

Note: Reference should  be made to the original specification for details of the test procedures.


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