Abstract / scope
Covers a method based on the selection of a gas chromatography column allowing the separation of the impurities to be determined. A gaseous test portion is passed through this column and the peaks obtained are detected by flame ionization and compared with those derived from an external standard. Columns and operating conditions having been found suitable for such a test are indicated in Annex A while Annex B lists the absolute retention times indicated in minutes. Annex C includes a typical chromatogram from an alumina column.