Residue dynamics of 10% thifensulfuron methyl in wheat and soil

This paper is to evaluate the safety level of thifensulfuron Me by analysing its residue after applied to the wheat field. Oscillation extension, solid-phase extension and high performance liquid chromatography (HPLC) have been used in the residue analysis. The pesticide residual concentration and its dynamics and residues in wheat and soil were evaluated. The pre-treatment methods of soil, wheat plant and grain were different. The average recoveries of thifensulfuron in soil, wheat plant and grain were 87.57%-90.70%, 89.39%-95.90% and 84.17%-89.32% respectively. These results showed that the method has met the requirement of pesticide residue analysis. Field trials were conducted in Changsha and Qufu. With the time increasing, thifensulfuron-Me residues gradually declined. The degradation was in accordance with the regression equation. When the applied herbicide concentration was 33.75 g/hm2 the degradation dynamic equation was respectively y)0.131e-0.09x and y)l.201e-0.13x in the soil and wheat plant in Changsha. When the wheat straw was treated by thifensulfuron Me wettable powder at 225 g/hm2 (effective ingredient is 22.5 g/hm2), the residue in kernel was undetected. The result implied that thifensulfuron Me belongs to non-persistent pesticides. Applying thifensulfuron Me at recommendatory dosage is environmentally secure in China.

Authors: Zhao, Jia; Yang, Renbin; Luo, Huili; Tang, Zhen; Qi, Li, ;Full Source: Anquan Yu Huanjing Xuebao 2010, 10(6), 22-25 (China). ;