Pydiflumetofen is a novel and efficient broad-spectrum chiral fungicide consisting of a pair of enantiomers. A simple and sensitive chiral analytical method was established to determine the enantiomers of this chiral fungicide in food and environmental samples by ultra-high-performance liquid chromatography tandem triple quadrupole mass spectrometry (UHPLC-MS/MS) using QuEChERS method coupled with octadecylsilane-dispersive solid-phase extraction (C₁₈-dSPE) as extraction procedure. The specific optical rotation and the absolute configuration of the enantiomers were identified by polarimetry and electronic circular dichroism (ECD). The elution order of the pydiflumetofen enantiomers on Lux Cellulose-2 was S-(−)-pydiflumetofen and R-(+)-pydiflumetofen. The average recoveries of eleven matrices ranged from 71.3% to 107.4%. The intraday relative standard deviations (RSDs) were less than 11.8%, and the interday RSDs were less than 12.6% for the two enantiomers. Stereoselective dissipation in pakchoi and soil were observed: S-(−)-pydiflumetofen was degraded faster than R-(+)-pydiflumetofen in pakchoi, causing the enantiomer fraction (EF) of the enantiomers to change from 0.50 to 0.42 in 7 days. However, R-(+)-pydiflumetofen was degraded faster than S-(−)-pydiflumetofen in soil, causing the EF of the enantiomers to change from 0.49 to 0.52 in 21 days. This study provides a method for monitoring pydiflumetofen enantiomer residues, which is crucial for improving risk assessments and the development of chiral pesticides.

Pydiflumetofen是由一对对映异构体组成的新型高效广谱手性杀菌剂。建立了一种简单灵敏的手性分析方法，通过QuEChERS方法与十八烷基硅烷分散体结合使用超高效液相色谱串联三重四极杆质谱（UHPLC-MS / MS）测定食品和环境样品中的手性杀菌剂的对映体固相萃取（C ₁₈ -dSPE）作为萃取程序。通过旋光法和电子圆二色性（ECD）鉴定对映异构体的特定旋光度和绝对构型。吡二氟美托芬对映体在Lux Cellulose-2上的洗脱顺序为S -（-）-吡二氟美托芬和R-（+）-吡二氟甲酚。11种基质的平均回收率在71.3％至107.4％之间。两种对映体的日内相对标准偏差（RSD）小于11.8％，日间RSD小于12.6％。在小白菜和土壤中观察到立体选择性消散：S -（-）-pydiflumetofen的降解速度快于小白菜中的R -（+）-pydiflumetofen，导致对映体的对映体分数（EF）在7天内从0.50改变为0.42。但是，R -（+）-pydiflumetofen的降解速度比S快-（-）-pydiflumetofen在土壤中，导致对映体的EF在21天内从0.49变为0.52。这项研究提供了一种监测pydiflumetofen对映异构体残留的方法，这对于改善风险评估和开发手性农药至关重要。