IP 277 : 72(R1995)

Four methods are described for the determination of icing inhibitor in aviation turbine fuels within the range of 0.02 to 0.2% v/v. The methods are equally applicable to additives consisting wholly of ethylene glycol monomethyl ether (methyl cellosolve, 2-methoxy ethanol) or this material containing 0.4% glycerol. In Method A the icing inhibitor is determined directly by infrared spectroscopy. In the remaining three methods the determination is carried out on an aqueous extract of the fuel. Method B employs a gas chromatographic finish, while Methods C and D depend on oxidation of the inhibitor with potassium dichromate/sulphuric acid. Excess dichromate is determined iodometrically in Method C and colorimetrically in Method D - using a comparator disk. Method D is suitable for rapid field test