Abstract:

In order to clarify the residue and degradation dynamics of botanical pesticide matrine in pear and soil, gas chromatography with nitrogen phosphorus detector (NPD) was used to analyze the degradation dynamics and residue of marine in pear and soil in Tianjing and Anhui for this study. The results indicated that the limit of detection of matrine in pear and soil was 1.36×10^-12 g, and the lowest detected concentrations were 0.01 mg·kg^-1 in pear and 0.004 mg·kg^-1 in soil, respectively. In Tianjing province, the half-life of matrine in pear and soil were 4.89 and 4.77 d respectively. While, in Anhui, the half-life of matrine in pear and soil were 3.94 and 5.27 d respectively. The degradation rules of matrine in pear and soil in Tianjing and Anhui can fit the degradation dynamic equation. When matrine was applied with low and high dosages for three and four times at an interval of 7 d, the final residue in pear and soil were lower than the temporary maximum limit value (MRL) 5 mg·kg^-1in national food safety standard-maximum residue limits for pesticides in food after 7-28 d of application. Therefore, matrine is low residue and easily degradation pesticide on pears and soil. Under standard use conditions, there is no dietary risk when it is applied on pears, so it is relatively safe to apply.

Key words: matrine, pear, residue, degradation dynamic