Simultaneous enantioselective determination of two succinate- dehydrogenase-inhibitor fungicides in plant-origin foods by ultra-high performance liquid chromatography−tandem mass spectrometry

Abstract

Fluindapyr and penthiopyrad are two new succinate-dehydrogenase-inhibitor fungicides both employed as racemic mixtures of enantiomers to control various fungal pathogens. In the present work, a robust and highly-sensitive method for simultaneous determination of fluindapyr and penthiopyrad enantiomers in plant-origin foods (cereals, fruits and vegetables) was developed using UPLC-MS/MS combined with a chiral stationary phase. Rapid baseline chiral separation of four stereoisomers of fluindapyr and penthiopyrad was obtained within 4.2 min on chiral MX(2)-RH column under reversed-phase conditions (with the eluent of acetonitrile/0.1% formic acid in water =70/30 (V:V) and column temperature maintained at 30 °C). The plant-origin samples were extracted quickly with acetonitrile and purified with multi-walled carbon nanotubes. Excellent linearity for the target analytes was observed in the concentration ranging from 1 to 250 µg/L with regression coefficient no less than 0.9967. The mean recoveries of fluindapyr and penthiopyrad enantiomers from six matrices were 77.1–107.2%, with all relative standard deviations values lower than 9.1%. The limit of quantification of four stereoisomers of two target chiral fungicides was 5 µg/kg. The analysis of real samples reveal that the developed method is suitable for the simultaneous chiral determination of fluindapyr and penthiopyrad residues in cereals, fruits and vegetables samples at enantiomeric level and can support their further investigation on enantioselective environmental behaviors and residue surveillance.