Simultaneous Monitoring of Isopyrazam Isomer Stereoselectivity in Cucumbers and Tomatoes: A Green Chromatographic...

A comprehensive understanding of the stereoselective behavior of chiral pesticides in crops is essential for the development of high-efficiency, low-risk single-isomer pesticide products. In this study, the separation performance of six chiral stationary phases for four isopyrazam isomers was systematically evaluated by using supercritical fluid chromatography (SFC). Key chromatographic parameters were optimized to establish a rapid and efficient SFC-MS/MS method that achieves baseline separation of the four isomers within 5 min. The field dissipation results revealed significant species-specific and organ-specific differences in the stereoselective behavior of isopyrazam in cucumber and tomato crops. The high-activity 1R,4S,9R-isopyrazam degraded rapidly in edible fruits but persisted longer on disease-prone leaves, making it a promising candidate for efficient chiral pesticide development. This study underscores the importance of elucidating the environmental fate of chiral pesticides and provides critical scientific evidence to guide the strategic development and application of stereoisomer-specific agrochemicals.