Wolters André, Leistra Minze, Linnemann Volker, Klein Michael, Schäffer Andreas, Vereecken Harry
Forschungszentrum Jülich GmbH, Institute of Chemistry and Dynamics of the Geosphere IV: Agrosphere, 52425 Jülich, Germany.
Environ Sci Technol. 2004 May 15;38(10):2885-93. doi: 10.1021/es035061m.
Calculation of pesticide volatilization from plants as an integral component of pesticide fate models is of utmost importance, especially as part of PEC (predicted environmental concentrations) models used in the registration procedures for pesticides. A mechanistic approach using a laminar air-boundary layer concept to predict volatilization from plant surfaces was compared to data obtained in a wind-tunnel study after simultaneous application of parathion-methyl, fenpropimorph, and quinoxyfen to winter wheat. Parathion-methyl was shown to have the highest volatilization during the wind-tunnel study of 10 days (29.2%). Volatilization of quinoxyfen was about 15.0%, revealing a higher volatilization tendency than fenpropimorph (6.0%), which is attributed to enhanced penetration of fenpropimorph counteracting volatilization. Predictions of the boundary-layer approach were markedly influenced by the selected values for the equivalent thickness of the boundary layer and rate coefficients, thus indicating that future improvements of the approach will require a deeper understanding of the kinetics of the underlying processes, e.g. phototransformation and penetration. The boundary-layer volatilization module was included in the European registration model PELMO, enabling simultaneous calculation of volatilization from plants and soil. Application of PELMO to experimental findings were the first comprehensive PEC model calculations to imply the relevant processes affecting the postapplication fate of pesticides.
将植物表面农药挥发作为农药归趋模型的一个组成部分来计算至关重要，特别是作为农药登记程序中使用的PEC（预测环境浓度）模型的一部分。将一种使用层流空气边界层概念来预测植物表面挥发的机理方法与在风洞研究中对冬小麦同时施用甲基对硫磷、粉唑醇和喹氧灵后获得的数据进行了比较。在为期10天的风洞研究中，甲基对硫磷的挥发率最高（29.2%）。喹氧灵的挥发率约为15.0%，显示出比粉唑醇（6.0%）更高的挥发趋势，这归因于粉唑醇增强的渗透作用抵消了挥发。边界层方法的预测受到边界层等效厚度和速率系数所选值的显著影响，因此表明该方法未来的改进将需要更深入地了解潜在过程的动力学，例如光转化和渗透。边界层挥发模块被纳入欧洲登记模型PELMO，能够同时计算植物和土壤的挥发。将PELMO应用于实验结果是首次全面的PEC模型计算，以暗示影响农药施用后归趋的相关过程。
