ASTM International Standard Test Method for Determination of Ethoxyl or Hydroxyethoxyl Substitution in Cellulose Ether Products by Gas Chromatography ASTM D4794-94(2017)

This test method is applicable to the determination of ethoxyl or hydroxyethoxyl substitution in cellulose ether products by a Zeisel gas chromatographic technique. The equipment and materials to be used shall include reagents, gas chromatograph, electronic integrator, column, syringe, reaction vials, caps, heating block, and a cover. The following reagents are as follows: iodoethane, O-xylene, toluene, hydrochloric acid, and colume packing. When a cellulose ether containing ethyl or hydroxyethyl substitutes is allowed to react with hydriodic acid, one mole of iodoethane is liberated for each mole of ethoxyl or hydroxyethoxyl ether substituted on the cellulose chain. The iodoethane is extracted in-situ with o-xylene and quantitated by gas chromatography using an internal standard technique. It is recommended to run duplicate samples.