Dissipation and residues of rimsulfuron in potato and soil under field conditions.

The analytical method for the residue analysis of a sulfonylurea herbicide, rimsulfuron, and its dissipation in soil and potato plants under field conditions were studied. Rimsulfuron residues were determined by Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method and ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Mean recoveries ranged from 74.6 % to 106.2 % with relative standard deviations (RSDs) of 2.0 %-13.8 % at three different spiking levels for each different matrix. The limits of detection (LOD) of rimsulfuron were ranged from 0.3 to 1.4 μg/kg, while the limits of quantification (LOQ) ranged from 0.9 to 4.3 μg/kg in different matrixes. The dissipation dynamics of rimsulfuron in the field trials in Shandong and Zhejiang Province were investigated. The half-lives in potato seedlings were 4.1 days in Shandong and 4.3 days in Zhejiang, both with a dissipation rate of 90 % about 7 days after application. The half-lives in soil were 6.0 days in Shandong and 6.6 days in Zhejiang, and with a dissipation rate of 90 % over 28 days. The terminal residues in potato and soil were not detectable. The fact that all the terminal residues were below the maximum residue level (0.1 mg/kg) set by Japan and 0.05 mg/kg set by EU. Hence it was safe for the use of this pesticide and the results also could give a reference for maximum residue limits setting of rimsulfuron in potato in China.