Residue analysis, dissipation dynamics, and risk assessment of ipconazole in paddy environment by a modified QuEChERS/HPLC-MS method

Abstract

Ipconazole is used to control rice bakanae disease, but its residues may pose a risk to the environment and human health. In this study, the optimized QuEChERS pretreatment method combined with HPLC-MS analytical technique was used to establish a method for the determination of ipconazole residues in the paddy field environment. The dissipation dynamics of ipconazole in paddy soil and paddy water were studied, and the final residues in brown rice, rice plants, and rice husks were detected. The results showed that ipconazole had a good linear relationship with the peak area in the concentration range of 0.01–1 mg/L(R²>0.999). The LOD and LOQ were 0.0019–0.0046 mg/kg and 0.0063–0.0152 mg/kg, respectively. The intra-day and inter-day recoveries of ipconazole at three spiked levels were 77.36 %-107.26 % and 79.66 %-102.86 %, respectively. The RSDr and RSDR values were 0.86 %-9.16 % and 2.07 %-7.07 %, respectively. The half-life is less than 30 days, which belongs to the easily degradable pesticide. The residues of ipconazole in rice plants, brown rice, and rice husks were lower than LOD at 7 days before harvest. These findings are helpful to monitor the residue of ipconazole in rice fields.