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Linuron linuron residues in corn plants, grain and soil were measured in samples linuron validation study. Aqueous solution of methanol extraction, SPE C 18 column combined with the petroleum ether liquid-liquid purification, distribution the stainless a Kromasil 5μmC 18 column high-performance liquid chromatography UV grating and diode array detector analysis technology, the residual dynamics of the corn plant, grain and soil degradation rule and the final residue was analyzed by HPLC. In addition, using LC-MS-APCI detection technology confirmatory sample linuron. Performance liquid chromatography ultraviolet the grating detection analysis technology minimum detectable amount of 2 × 10 -9 g, WATERS 2996 diode array detector minimum detectable than grating detector is slightly lower; method minimum detectable concentration was 0.02mg · kg -1 . Add add recovery test concentration of 0.05mg · kg -1 , 0.1mg · kg -1 , 1.0mg · kg -1 , each add a level of recoveries were 83.7% to 94.7% (corn grain), 93.3% to 105.3% (corn plants), 96.0% to 109.7% (soil). In the corn field after sowing before spraying 50% linuron WP 2812.5g · hm -2 (active ingredient), the 2-year test results show that: the measured residual amount applied on corn plants Drug 14d 0.08mg · kg -1 (2002), after application 15d 0.39mg · kg -1 (2003 years); the original deposited on the soil The amount 4.58 ~ 7.02mg · kg -1 , sampling 14d after application, the degradation rate of 72 to 80%. After application 115d, the degradation rate of 92% (2002). Plants in the first sampling time (2002), spraying the 14d and 15d (2003 years), and therefore establish the dynamic equations of Field Degradation of no practical significance. Linuron soil degradation need to use C t = C the 0 t -k that equation. The Valley Long soil degradation dynamic equations in 2002 Facilitation: the C t = 3.68t -0.3363 r = -0.9373, half-life (T 1/2 < / sub> 2.1d; 2003 years: the C t = 2.39t -0.3745 r = -0.9086, T 1/2 1.8 d. short, in accordance with the evaluation criteria of the chemicals linuron in terms of the corn plant, or in the soil are all readily biodegradable pesticides. simultaneous determination of the final residues of linuron in corn grain, plants and soil. data from the measurement shows that the two places, whether high-dose or low-dose pesticide, the linuron content in corn grain, plants are lower than the minimum detectable concentration of the method. slightly higher amount of residue in the soil of 50% linuron WP degradation is slow, the final residue in the soil samples was 0.46 mg · kg -1 (in 2002), 0.53mg · kg -1 (2003), according the results of the study, reference linuron residues in corn and soil degradation dynamics, it is recommended that 50% the linuron WP reasonable guidelines for the use of corn an application rate not higher than 1875g · hm -2 (active ingredient), application, application away from harvest intervals of not less than 30d. linuron the ADI value U.S. EPA (US.EPA), identified as 0.002mg · kg -1 < / sup>, and MRL provisions linuron feed corn 1mg · kg -1 , cereals 0.25mg · kg -1 ;
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