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Residual Dissipation Dynamics of Hexazinone and Diuron in Sugarcane and Soil and Adsorption Behavior of Diuron in Soil

Author: XieMengXing
Tutor: LiXueDe
School: Anhui Agricultural University
Course: Environmental Science
Keywords: Diuron Hexazinone Residue degradation dynamics Soil adsorption
CLC: X592
Type: Master's thesis
Year: 2010
Downloads: 129
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Abstract

Firstly, study the establishment of a sugar cane plants, soil, sugar cane diuron and hexazinone residue analytical methods, on this basis, through field trials to study diuron and hexazinone in sugarcane plants and soil residue degradation dynamics and final residues, and using batch equilibrium experiments studied diuron in soil adsorption characteristics. The main results are as follows: 1. Sugarcane plants, soil and sugarcane diuron sugarcane residue analytical methods plant samples with methanol as the extraction solvent, petroleum ether, chloroform liquid - liquid partition, alumina column chromatography after purification, determined by HPLC; soil samples using ethyl acetate as the extraction solvent mixture of methanol, concentrated extract, the volume was measured directly by HPLC; sugarcane samples were acetonitrile, ethyl acetate - methanol extract, after purification by column chromatography on alumina determined by HPLC. Spike recovery test results show that: In the 0.01mg/kg ~ 0.5mg/kg Add concentration range, sugar cane plants diuron average recovery was 75.0 ~ 85.5% coefficient of variation was 6.9 to 9.3%; at 0.005mg / kg ~ 0.08mg/kg added concentration range of soil Diuron average recovery was 82.0 ~ 85.2% coefficient of variation was 2.1 to 4.5%; 0.005mg/kg ~ 0.2mg/kg added in the concentration range, sugar cane Diuron average recovery was 75.0 ~ 85.7% coefficient of variation was 4.6 to 7.6%. Accuracy of the method, accuracy can meet the requirements of pesticide residue analysis. 2 Sugarcane plants, soil and sugarcane Hexazinone sugarcane residue Analysis of plant samples with ethyl acetate as the extraction agent, after purification by column chromatography on alumina, as determined by HPLC; soil samples were extracted with ethyl acetate and methanol mixture agents, the direct use of constant volume was concentrated by HPLC; cane samples with chloroform as extracting solvent, after purification by column chromatography on alumina was determined by HPLC. Spike recovery test results show that: In the 0.05mg/kg ~ 0.5mg/kg added concentration range, sugar cane plants Hexazinone average recovery was 73.0 ~ 83.3%, coefficient of variation of 2.5 to 3.4%; at 0.04mg / kg ~ 0.4mg/kg Add a concentration range of soil Hexazinone average recovery was 79.4 ~ 86.1%, coefficient of variation of 2.9 to 4.4%; 0.02mg/kg ~ 0.5mg/kg added in the concentration range, sugar cane Central triazone The average recovery was 84.1 ~ 95.7%, coefficient of variation of 1.4 to 6.1%. Accuracy of the method, accuracy can meet the requirements of pesticide residue analysis. 3 sugarcane and diuron residues in soil degradation dynamics in 2008 and 2009 in Anhui and Guangdong in field residue test results show that: diuron in sugarcane plants and soil degradation dynamics meet a residual kinetic equation. Xuancheng in Anhui test points, diuron in sugarcane plants in the elimination half-life of 1.72-3.47d, elimination half-life in soil is 11.96-21.36d; pilot sites in Zhanjiang, diuron in sugarcane plants digestion half-life of 4.62-14.41d, elimination half-life in soil is 10.36-12.57d. 4 sugarcane and soil degradation dynamics hexazinone residues 2008 and 2009 in Anhui and Guangdong in field residue test results show that: hexazinone in sugarcane plants and soil degradation dynamics meet a residual kinetic equation. Xuancheng in Anhui test points, hexazinone residues in sugarcane plants elimination half-life of 5.41-13.88d, digestion residues in the soil half-life of 4.45-10.03d; pilot sites in Zhanjiang, hexazinone in sugarcane plants in Central triazone elimination half-life of the residual 4.18-5.34 d, digestion residues in the soil half-life of 3.08-10.33d. 5 diuron, hexazinone in the final residue of sugar cane in Anhui and Guangdong, two pilot sites were sugar cane harvest has hexazinone, diuron detected. 6 diuron in soil adsorption diuron in yellow-brown and red loam soil adsorption Freundlich isotherm equation can be used to describe the adsorption constants K _f, respectively 10.7053,8.7740 adsorption absolute value of free energy change were 15.41,16.22 kJ · moL ^{-1 , instructions diuron in these two pilot sites in the soil adsorption dominated by physical adsorption; diuron in yellow brown soil and red loam on the KOM is 502.60,696.35, indicating that diuron in both soil Mobility weak; soils Hexazinone added two soils inhibit the adsorption of the enemy Long grass with hexazinone Add concentration increases, the absorption intensity is reduced accordingly; when the soil by adding water-soluble organic matter (DOM), the soil adsorption constant enemy Long grass correspondingly reduced, indicating that the DOM addition inhibits Long grass enemy soil adsorption.}

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