Studies On The Repellent Activity To Termite Of The Essential Oil Of Cunninghamia Lanceolata

In this study, I researched the yield of essential oil in Cunninghamia Lanceolata by different extraction method and technology, I researched the contact toxic and repellent activity of essential oil of Cunninghamia Lanceolata by contact toxicity and the filter paper-dipping method for Reticulitermes chinensis Snyder; I separated essential oil by the column chromatography, and researched the contact toxicity of different separation of essential oil; I researched the distribution discipline of essential oil wi thin the Cunninghamia Lanceolata, the main research conclusions are as follows:(1)The optimum extraction conditions of steam distillation were:ratio between solvents and raw material:8.0, the mesh number:30mesh, time:3.5hour.(2)The optimum extraction conditions of supercritical carbon dioxide extraction was:the extraction pressure:30Mpa, extraction temperature:40℃, extraction time:120min, flow rate:20Kg/h, mesh number:30mesh. Supercritical carbon dioxide extraction compared with the traditional method, it had advantages of fast, efficient, high-selectivity, high-security, low-energy consumption and so on. And the essential oil has light color, transparent shape, high purity, less pollution, et al.(3)The essential oil in the heartwood of Cunninghamia Lanceolata had the stronger contact toxicity and the repellent activity. When the concentrati on was160mg/L, the termite mortality was100%after72h; the rate of repellent was57.14%when the concentration was50mg/L.(4)The separation of essential oil in the heartwood of Cunninghamia Lanceolata by the column chromatography, the experimental results show that:when the ratio of normal hexane and anhydrous ether was8:2and6:4, the separate matter of essential oil was most, they were67.3%and22.3%, the component accounted for oil was89.6%. The result of contact toxic of differrent separation showed that:after the essential oil in composition separation, the contact toxicity of each separation was far less than before without separation. The highest mortality rate was30%; and the highest mortality rate was60%was also less than before, the results of contact toxicity of different separation combination showed.(5)The distribution of essential oil in Cunninghamia Lanceolata had the obvious characteristics:The essential oil content has degressive tendency from the top of the tree to the roots, the essential oil in heartwood had the highest content, but it in sapwood accounted for only a very small proportion, could be ignored.