Abstract: 【Objective】 The objective of this study is to research degradation dynamics of chlorantraniliprole in the vegetable and soil, and to formulate a scientific basis for the reasonable spray volume and the safe interval period on controlling vegetable pests.【Method】Degradation dynamics and terminal residue of chlorantraniliprole of 20% chlorantraniliprole SC in cabbage and soil were investigated by QuEChERS-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).【Result】 The recoveries of chlorantraniliprole from the cabbage and the soil were 81.25%-92.05% and 82.92%-93.38%, respectively. The residues in the cabbage and soil were proved to chlorantraniliprole through qualitative analysis by HPLC-MS/MS. Degradation dynamic equations of chlorantraniliprole in cabbage and soil fitted the first-order reaction dynamic equations. The half-lives of degradation of chlorantraniliprole in cabbage and soil were 7.66 and 6.86 d, respectively. The final residues of chlorantraniliprole were not detected in cabbage and 0.0071 mg•kg-1 in soil, respectively, when 20% chlorantraniliprole SC was applied at 0.045 g•m-2. The final residues of chlorantraniliprole were 0.0063 mg•kg-1 in cabbage and 0.1004 mg•kg-1 in soil, respectively, when 20% chlorantraniliprole SC was applied at 0.090 g•m-2.【Conclusion】20% chlorantraniliprole SC was applied at 0.045 and 0.090 g•m-2 could be considered safe in the cabbage field.

Key words: chlorantraniliprole, QuEChERS, HPLC-MS/MS, degradation, residue