| The residual determination methods of Diuron and Hexazinone in sugarcane plant,soil,sugarcane were established,by which the residue dynamics of Diuron and Hexazinone in sugarcane plant,soil and the final residues in soil and sugarcane were studied.Adsorption behaviors of Diuron in soil using Batch equilibration technique were studied in this dissertation, as well.The main results were shown as follows.1.The determination methods for Diuron residues in sugarcane plant,soil,sugarcanePlant samples were extracted with methanol,petroleum ether and chloroform by liquid-liquid partition,cleaned up by alumininia chromatographic column,and determinated by HPLC-UV.Soil samples were extracted with mixture of ethyl acetate and methanol,and determinated by HPLC-UV.Sugarcane samples were extracted with mixture of acetonitrile,ethyl acetate and methanol,cleaned up by alumininia chromatographic column,and determinated by HPLC-UV.The average recoveries and coefficient of variations of the method were75.0～85.5%,6.9～9.3 % for plant samples,82.0～85.2%,2.1～4.5% for soil samples,75.0～85.7%,4.6～7.6% for sugarcane samples,respectively.The accuracy and precision of the method accorded with the demands of pesticide residues analysis.2.The determination methods for Hexazinone residues in sugarcane plant,soil,sugarcanePlant samples were extracted with ethyl acetate,cleaned up by alumininia chromatographic column,and determinated by HPLC-UV.Soil samples were extracted with mixture of ethyl acetate and methanol for 3 times,and determinated by HPLC-UV.Sugarcane samples were extracted with chloroform for 3 times,cleaned up by alumininia chromatographic column,and determinated by HPLC-UV.The average recoveries and coefficient of variations of the method were73.0～83.3%,2.5～3.4 % for plant samples,79.4～86.1%,2.9～4.4%for soil samples,84.1～95.7%,1.4～6.1%for sugarcane samples,respectively.The accuracy and precision of the method accorded with the demands of pesticide residues analysis.3. Residual dissipation dynamics of Diuron in sugarcane plant and soilThe residual dissipation dynamics of Diuron in sugarcane plant and soil were studied in Anhui and Guangdong during 2008 and 2009.The results show that the dissipation kinetics of diuron meet with the first-order kinetic process.In Anhui Xuancheng during 2008 and 2009,the half-life was 1.72 - 3.47 days in sugarcane plant ,11.96-21.36days in soil respectively.In Guangdong Zhanjiang during 2008 and 2009, the half-life was 4.62-14.41 days in sugarcane plant , 10.36-12.57days in soil ,respectively.4.Residual dissipation dynamics of Hexazinone in sugarcane plant and soilThe residual dissipation dynmics of Hexazinone in sugarcane plant and soil were studied in Anhui and Guangdong during 2008 and 2009.The results show that the dissipation kinetics of hexazinone meet with the first-order kinetic process.In Anhui Xuancheng during 2008 and 2009, the half-life was 5.41 -13.88 days in sugarcane plant, 4.45- 10.03days in soil,respectively;. In Guangdong Zhanjiang during 2008 and 2009,the half-life was 4.18- 5.34 days in sugarcane plant , 3.08-10.33days in soil ,respectively.5.The final residues of Diuron and HexazinoneThe final residues of Hexazinone and Diuron in sugarcane were less than LOQ in Anhui Xuancheng and Guangdong Zhanjiang.6.Adsorption behavior of Diuron in soilsThe soption isthems of Diuron in yellow brown soil and red soil using Batch equilibration technique were studied.The adsorption of Diuron varied with the Hexazinone and dissolved organic matter in sewage and sludge.The results indicated that the istherm data in two soils were fitted to the Freundlich equation.Adsorption coefficient (Kf) of Diuron in yellow brown soil and red soil was 10.7053,8.7740,respectively, and KOM was 15.41,16.22kJ·moL-1,suggesting that adsorption in the two soils was physical processes, and Diuron had a weak mobility in soils according to McCallˊs classification system.With the concentration range of the Hexazinone spiked into soils ,the sorption capacity of soil reduced and the effect of Hexazinone on the sorption capacity of soil weaken with larger concentration of Hexazinone .Within the concentration range of the DOM derived from sewage and sludge,the sorption capacity of soil reduced after spiking DOM into soils.
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