Studies on the Chemical Composition of Essential Oil from Sap of Rhus Lac Tree

The chemical composistions of the essentail oil of laccol and urushiol from the sap of Chisese lacquer tree are studied by GPC and GC-MS-DS techniques.The main components of these oils are 3-C15 and 3-C17 alkylatechols,respestively,wich were identified by their standard samples.The most abundant constituents are the monoenyl laccol and the trienyl urushiol.The other components are 4-C15 alkylcatechols and 3-C15 and C17 alkylphenol.More than 98% of the commponents in essential oil were separated and identified by GC.The sap of lacquer tree contains 7%～9% of polymeric urushiol.