Simultaneous determination of enantiomeric residues of flutriafol, hexaconazole and diniconazole in fruits and vegetables on a bridged cyclodextrin-based column by HPLC

Abstract

The new type of bis-triazolyl bridged cyclodextrin-based stationary phase (BCDP) was prepared through “Click reaction”. BCDP had high selectivity for triazoles and was used for the simultaneous fast separation and determination of enantiomeric residues (flutriafol, hexaconazole and diniconazole) in fruits and vegetables by high-performance liquid chromatography (HPLC). The QuEChERS method assisted by magnetic nanoparticles was used for sample pretreatment, and then a gradient elution was carried out by using MeOH-H2O as the mobile phase on BCDP to achieve rapid resolution of the triazole enantiomers within 25 min. After condition optimization, simultaneous baseline separations of the six enantiomers were achieved with resolutions of 1.54 (flutriafol), 2.27 (hexaconazole) and 1.97 (diniconazole). A new HPLC quantification method of the six enantiomeric residues in apples, tomatoes and cucumbers was established by an internal standard with a photo-diode array (PDA) detector at 210 nm. The results showed that the excellent linear relationships of all triazole enantiomers were observed in the concentration range of 0.5–50 mg L-1 (R2 = 0.9986–0.9999). The average recoveries of enantiomers in fruits and vegetables were from 91.95 % to 109.92 % with RSDs of 0.97 %–1.32 % for intraday and 1.30 %–3.03 % for interday. The limits of detection (LODs, S/N = 3) and limits of quantitation (LOQs, S/N = 10) of all enantiomers were less than 0.03 mg kg−1 and 0.10 mg kg−1, respectively. BCDP had high selectivity for triazole due to its synergistic inclusion with triazoles and advantage in fast and simultaneous separation of multiple triazole enantiomers, which could save analysis time and reduce solvent consumption. BCDP was a new separation material for the scientific evaluation of chiral pesticides in the food safety analysis.