| Abstract:A method for rapid determination methoxyl content in lignin by headspace gas chromatography was introduced， and its accuracy and reliability were verified by twelve lignin model compounds. This method included adding lignin sample and 0.5 mL hydroiodic acid into a closed headspace sample vial， reacting at 130℃ for 30 min， then injecting trisodium citrate dihydrate solution to neutralize the sample， and determining the content of iodomethane in the sample vial by HS-GC. The results showed that the methoxyl content of the spruce wood powder extracted with acetone was 4.6560 mmol/g by this method （based on Klason lignin）， and the methoxyl content was 4.6028 mmol/g by titration as the control method with the RSD <1%. This method was simple， accurate and had good precision. It could be used to effectively determine the content of methoxyl in lignin and related substances. |
