Abstract: The degraded products of lignin were identified by gas chromatography-mass spectrometry (GC-MS) during GIF biomimetic bleaching of bamboo pulp to explore lignin degradation mechanism. The results showed that residual lignin was further degraded by GIF biomimetic system. The main ways of lignin degradation were involved with demethylation, formation and opening of quinone-type structures, cleavages of alkyl-aryl ether bond and carbon-carbon linkage in side-chain. The degraded products contained much carbonyl compounds, which was the result of catalytic oxidation in GIF biomimetic system. The pulp brightness was improved because of the removals of some quinone-type structures, conjugated carbonyl and phenolic compounds. Some carbohydrate-degraded products were also detected out by GC-MS.

Key words: bamboo pulp, GIF, biomimetic bleaching, lignin-degraded products, GC-MS