Industrial Methylated Spirits; IMS
Industrial Denatured Alcohol
DEFINITION
Industrial Methylated Spirit is a mixture of nineteen volumes of ethanol of an appropriate strength with one volume of approved wood naphtha. Two strengths are available containing 99% by volume and 95% by volume of alcohol (also known as 74 OP and 66 OP respectively).
CHARACTERISTICS
A colourless, clear, mobile, volatile liquid, boiling at about 78°.
IDENTIFICATION
Mix 0.1 mL with 0.05 mL of an 11% w/w solution of orthophosphoric acid and 0.25 mL of dilute potassium permanganate solution. After 1 minute add a few mg of sodium metabisulfite and shake until the mixture is decolorised. Add 1.5 mL of a 50% v/v solution of sulfuric acid and a few mg of finely powdered chromotropic acid sodium salt, shake well and heat on a water bath for 5 minutes. A deep violet colour is produced.
TESTS
Acidity or alkalinity
25 mL requires not more than 0.2 mL of 0.1M sodium hydroxide VS to produce a pink colour with phenolphthalein solution R1 and not more than 1.0 mL of 0.1M hydrochloric acid VS to produce a red colour with methyl red solution.
Clarity of solution
Dilute 5.0 mL to 100 mL with water. The solution is clear, Appendix IV A.
Apparent density
For ‘66 OP’ grade, not greater than 811.6 kg m , and for ‘74 OP’ grade, not greater than 792.8 kg m ,
Appendix V G.
Aldehydes
To 5.0 mL add 5 mL of water and 1 mL of decolorised fuchsin solution and allow to stand for 30 minutes. Any colour produced is not more intense than that obtained by treating in the same manner 5 mL of a 0.005% w/v solution of redistilled acetaldehyde in aldehyde-free ethanol (96%) (50 ppm).
Non-volatile matter
When evaporated and dried at 105°, leaves not more than 0.01% w/v of residue.
