This method is not specific for maleic anhydride. The polarographic method specified in part 7 should be used. The principle is based on the oxidation of unsaturated organic acids and anhydrides in a test portion with an excess of cold standard volumetric potassium permanganate solution in the presence of sulphuric acid, followed by iodometric determination of the potassium permanganate remaining. - ISO 1389, Parts 1 to 11, replace ISO Recommendation R 1389-1970.
95.99 Withdrawal of Standard
May 27, 2002