Residual Dynamics Study Of Two Pyrethroid Pesticides In Honeysuckle

From the perspective of actual production, the test and research were performed in order to ensure the quality and safety of Honeysuckle, and break through the green barriers builted by Europe and other countries on China’s export of traditional Chinese medicine. Refer to commenly used pesticides in Honeysuckle, residual dynamics of crpermethrin and cyhalothrin were carried out, wich provided bases for the development of pesticides MRLs, and put forward some suggestions for the safety use of cypermethrin and cyhalothrin. In addition, impacts of Nitenpyram on the contents of two active ingredients in Honeysuckle were studied, so as to provide fundamental data for the further study.The scientific results were obtained as follows:a) Methods were developed for the determination of cypermethrin and cyhalothrin residues in Honeysuckle, respectively. Both of the pesticides can be ultrasonic extracted by actone, followed by concentration, then can be analysed by Gas Chromatography. The average added recoveries of cypermethrin at two added levels (0.10 mg/Kg,0.20 mg/Kg) were 94.2% and 93.1%. As for cyhalothrin, the average added recoveries at two added levels (0.20 mg/Kg,0.50 mg/Kg) were 87.0% and 93.1%. The minimum detectable amount of cypermethrin and cyhalothrin were 0.10 mg/Kg. According to NY/T788-2004, this method can be used for the determination of cypermethrin and cyhalothrin in Honeysuckle, separately.b) ResiduaL dynamics were performed for cypermethrin and cyhalothrin in this study. The Honeysuckle samples were got after treatment of pesticides at different sampling time, and then the residues were measured. Residual dynamic curves were prepared by pesticide residues against sampling time for both of the pesticides. At recommended dose, the residue dynamic equations for cypermethrin and cyhalothrin were C=20.9e-0.339t and C=7.57e-0.312t. The half-life of two pesticides in Honeysuckle were 1.9 days and 1.8 days at recommended dose. As for triple dose, the half-life were 1.8 days and 1.7 days. The MRLs of cypermrthrin and cyhalothrin shouLd be 0.20 mg/Kg after recommendation, and the safety interval should be 11 days and 16days.c) The impacts of Nitenpyram on the contents of chlorogenic acid and galuteolin in Honeysuckle were preliminarily studied. After treatment of Nitenpyram, the content of chlorogenic acid was increased by 9%, whereas the content of galuteolin was decreased by 9%. The statistical analysis was performed using SPSS statistical software. The results showed Nitenpyram had an extremely significant influence on contens of chlorogenic acid compared to control plots (P<0.01). Meanwhile, the P value for galuteolin is less than 0.05, which showed a significant influence compared to control plots. Because of the significant inhibitory effect on the growth of Honeysuckle during field testing, Nitenpyram is NDt suggested to control Honeysuckle pests.