Analytical method for the determination of guvermectin residues in rice environment by the QuEChERS method combined with HPLC

The objective of this pilot study was to develop an analytical method for the determination of guvermectin residues in paddy water, soil, and rice using QuEChERS pre-treatment combined with Agilent 1260 Generation II high-performance liquid chromatography. The samples were extracted with acetone, purified with C18 absorbent, and filtered through a 0.2-μm organic filter membrane. The limits of detection (LODs) and limits of quantification (LOQs) for guvermectin in paddy water, paddy soil, and rice were 0.0022, 0.0041, and 0.0068 mg/kg and 0.0073, 0.0138, and 0.0227 mg/kg，respectively. The linear relationship was good in the range of 0.01–5 mg/L, and the linear correlation coefficient (R2) was greater than 0.9990. The average recoveries at three spiked levels (0.1, 0.5, and 1.0 mg/kg) ranged from 87.32% to 112.53%, with relative standard deviations (RSDs) ranging from 1.07% to 2.48%. The extended uncertainty was 3.74–3.87% at a coverage level of k = 2 and a confidence level of approximately 95%. These results demonstrate that the method is simple, fast, highly accurate, and sensitive, and it can meet the requirements for determination of guvermectin residues in the rice field environment.