Residues Dynamics Of Procymidone In Tomatos

Procymidone belong to the phthalic acid amide pesticides, it is a toxicity fungicides. The survey show that procymidone is widely used in the prevention and control of Botrytis cinerea, but the farmers couldn’t use the drugs reasonably, resulting in growing pesticide residues. Thus, this research focus on established a effective HPLC method to monitor procymidone, and evaluated dynamic of residual procymidone of tomato fruit in the greenhouses. This study is essential for the development of its reasonable use and verified maximum residue limits of procymidone in tomotoes. The main results of this study have achieved:1. Established an effective high performance liquid chromatography(HPLC) method for detecting of residual procymidone. The results show that: in the concentration range 0.1-20 ug / mL, a linear correlation existed in the procymidone standard working curve Y = 23504 x + 3099.1, with the correlation coefficient R2 of 0.9899. The range of adding recoveries in tomatoes was 81.55-86.65% while the coefficient of variation was only 4.08-5.22%,;2. We monitored the dynamic degradation of procymidone in tomatoes after treated the fruit with the recommended dose, 750 g ai / hm2, of 50% procymidone WDG once. Results show that the degradation of procymidone matched the first-order kinetics equation very well, with 4.88 days digestion half-life.3. The final residue of procymidone in tomatoes was also studied with the does of 750 g a.i./hm2 and double does of the drug, namely 1500 g a.i./hm2 respectively. After sparying 4 times every 7 days, we tested the final residue 7 days after last treated by HPLC. The results showed that the final residue of high does and low dose were 0.55 mg / Kg, 0.14 mg / Kg in tomatoes. And 0.11mg/Kg procymidone could be detected the two weeks later which fruit was treated, while the low concentration of procymidone failed to detect procymidone residues.In summary, procymidone on tomatoes can be degradated in the natural conditions, procymidone is safety as long as we use the recommended spraying concentration(375-750 g a.i./hm2), and collected the fruit within one week after application.