Residues And Degradation Dynamic Of1.3%Matrine As In Chinese Cabbage And Soils

Matrine, which belongs to the quinolizidine derivatives lupin alkaloids, is pyridinealkaloids compounds existing in Sophora flavescens Ait. With good insecticidal andantibacterial activity, it is widely used as pesticide. There are some types of formulation ofmatrine in the market. In this study, based on the analyse of matrine by high performanceliquid chromatography (HPLC), the residual dynamic of1.3%soluble matrine in soil andChinese cabbage were analysed. The results provided not only a theoretical basis for theregistration and promotion of1.3%soluble matrine in Chinese cabbage but also an importantfoundation for the guidance of its rational use and the criterion of its maximum residue limits.1. A residue detection method of matrine by HPLC was established. The results showedthat, in the concentration ranging from0.1to20μg/mL, a linear correlation existed in thematrine standard working curve y=24782x+5220.8, with the correlation coefficient R2of0.9904. The range of adding recovery and coefficient of variation in Chinese cabbage were7.97%～83.42%and5.30%～5.70%, respectively, while in soil wre80.80%～88.45%and6.45%～9.31%, respectively.2. The dynamic of residue degradation of1.3%soluble matrine in cabbage and soil wasstudied by field plot test. After spraying in cabbage and soil one time with the dose of74.1ga.i./hm2, we tested the residue of matrine by HPLC. The results of residual degradationshowed that the degradation process of matrine in cabbage and soil were in accordance withthe first-order kinetics model with half-life of1.28d and1.45d, respectively.3. The final resiude of1.3%soluble matrine in cabbage and soil was also studied withthe dose of74.1g a.i./hm2and37.05g a.i./hm2, respectively. After spraying4times every7days, we tested the final residue7days before harvest by HPLC. The results showed that thefinal residue of high dose and low dose were0.0625mg/Kg,0.0482mg/Kg in Chinesecabbage,0.0495mg/Kg and zero in soil, respectively.In summary, matrine which can be easily degradated in the enviroment and cabbage, is akind of easily degradable pesticide.