Trace enantioselective determination of triazole fungicides in honey by a sensitive and efficient method

This work presents, for the first time, the simultaneous enantioselective determination of triazole fungicides (paclobutrazol, myclobutanil, diniconazole, and epoxiconazole) in honey samples by chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS). An efficient procedure, solid-phase extraction (SPE) coupled with dispersive liquid-liquid microextraction (DLLME), was used for the extraction, purification, and preconcentration of target analytes. In order to obtain high extraction efficiency, several experimental parameters including the type of SPE cartridge, the pH of sample, the type and volume of elution solvent and extraction solvent, and salt concentration were optimized. Upon optimal conditions, good sensitivity was achieved with limits of detection ranging from 0.005 to 0.028 ng/g and limits of quantification ranging from 0.017 to 0.093 ng/g. Recoveries for eight enantiomers were satisfactory lying between 87.1% and 108.6% in four different honey samples. The intra- and inter-day relative standard deviations were all below 9.1%. This convenient, sensitive, and reliable method was applied to the enantioselective determination of triazole fungicides in 11 honey samples. As a result, the concentrations and enantiomeric fractions of paclobutrazol were determined successfully.