Online SFE-SFC-MS/MS analysis of pyraclostrobin and chiral mefentrifluconazole residues in mango and mango juice.

This study established an on-line SFE-SFC-MS/MS method for the determination of mefentrifluconazole (MFZ) enantiomers and pyraclostrobin (PY) in mango and mango juice. Key parameters of SFC separation and SFE extraction have been optimized for high efficiency, sensitivity, and environmental friendliness. Enthalpy controlled enantioseparations of MFZ were recognized by thermodynamic analysis. Molecular docking estimated the enantiomeric recognition of MFZ enantiomers binding to the chiral stationary phase. The mean recoveries (RSDs) were in the range of 94.5-106.8 % (4.2-15.4 %), 91.1-103 % (3.6-10.3 %), 94.7-102.7 % (3.8-9.8 %), and 93.2-106.9 % (4.1-12.1 %) for R-MFZ, S-MFZ, racemic MFZ, and PY under 3 spiked levels of interday assays (n = 15). The LOQs of R-MFZ, S-MFZ, and PY were 0.5, 0.5, and 1 μg kg. The method was further applied to real samples in Guangxi Province, China with low acute and chronic dietary risk for MFZ and PY in mango and mango juice.