Development and Validation of an UHPLC-MS/MS Method for the Determination of 32 Pyrrolizidine Alkaloids in Chinese Wild Honey.

Background: Studies on pyrrolizidine alkaloid (PA) contamination in honey produced in China are scarce. Previously reported HPLC-MS/MSmethods for the determination of PAs in honey often suffer from insufficient separation and uncertainties in PA isomers. Objective: To develop and validate an Ultra-HPLC (UHPLC)-MS/MS method for baseline separation of PA isomers towards precise determination of 32 PAs in Chinese wild honey. Methods: PAs were extracted from honey samples and separated on an ACQUITY BEH C18 (2.1mm 100mm, 1.7 lm) column with (A) 0.1% formic acid aqueous solution containing 5mM ammonium acetate and (B) methanol as mobile phase. The column temperature was maintained at 30 °C, and flow rate was 0.3 mL/min. Detection was performed by tandem mass spectrometry. The total run time was reduced to 18 min. Results: Thirty-one of 32 PAs were baseline separated efficiently within 18 min. The LOD and LOQ were 0.06-0.25 lg/kg and 0.22-0.82 lg/kg, respectively, except for that of clivorine, for which LOD and LOQ were 2.03 and 6.78 lg/kg, respectively. The average recoveries ranged between 66.3 and 95.1% and the average RSDs were 3.2 to 8%. The established method was used to analyze PAs in 22 types of Chinese wild honey, and the predominant PAs found in these honey samples were intermedine and lycopsamine. Conclusion: A high-throughput method for the determination of isomeric PAs in honey was developed and validated. Five of the 22 types of Chinese wild honey were contaminated with PAs concentrations of 2.2-207.0 lg/kg. Highlights: A new method capable of monitoring more PAs and providing better separation than previously reported protocols for the determination of multiclass PAs in honey is established. [ABSTRACT FROM AUTHOR]