Five photodegradation products of metrafenone (MTF) and six of mepanipyrim (MEP) were identified in synthetic grape juice at 25 °C and the structures of the main reaction products established. The degradation of MTF and MEP was modelled by using three different strategies involving monitoring (a) the disappearance of the parent compound, (b) the conversion of the parent compound into its main structurally related reaction products and (c) the degradation of the parent compound to all intermediates and degradation end-products. The kinetic coefficients of degradation for these fungicides were determined and the corresponding half-lives found to be 20.8 h for MFT and 10.1 h for MEP. The proposed models afford reasonably accurate interpretation of the experimental data. Based on the results, modelling the kinetics of disappearance of the parent compound by itself does not ensure the best fit of the degradation behaviour of the fungicides.

在25°C的合成葡萄汁中鉴定出5种甲萘醌（MTF）和6种甲吡嘧啶（MEP）的光降解产物，并确定了主要反应产物的结构。通过使用三种不同的策略模拟MTF和MEP的降解，这些策略包括监测（a）母体化合物的消失，（b）母体化合物转化为其主要的结构相关反应产物以及（c）母体的降解与所有中间体和降解终产物混合。确定了这些杀真菌剂的降解动力学系数，发现相应的半衰期对于MFT为20.8 h，对于MEP为10.1 h。所提出的模型对实验数据提供了合理准确的解释。根据结果​​，