Residue Dynamic of Pyrimorph on Tomatoes, Cucumbers and Soil under Greenhouse Trails

摘要

A modified QuEChERS method for analysis of pyrimorph residue in tomatoes, cucumbers and soil was developed and validated. Residue dynamics and final residues in greenhouse vegetables and soil were studied. At fortification levels of 0.05, 0.1 and 1mgkg super(-1) in tomatoes, cucumbers and soil, the method got recoveries ranged from 86.1% to 99.3% with relative standard deviations of 1.0%-7.7%, in agreement with directives for method validation in residue analysis. The limit of determination in tomatoes, cucumbers and soil was 0.05mgkg super(-1). The proposed method was successfully employed for the determination of pyrimorph residue levels and dissipation rates in vegetables and soil. At six experimental sites, pyrimorph residues in tomatoes and cucumbers showed relatively fast dissipation rates, with half-lives of 5.8-7.7days and 5.7-7.1days respectively. Half-lives of pyrimorph in soil were 8.5-11.0days. The final residues of pyrimorph in tomatoes ranged from 0.19 to 3.66mg kg super(-1), 0.18 to 4.35mg kg super(-1) in cucumbers and 0.22 to 16.5mg kg super(-1) in soil with pre-harvest interval of 3-7days. 5mgkg super(-1) was proposed as the MRL of pyrimorph in tomatoes and cucumbers.