Analysis of phenolic acids and flavonoids in leaves of Lycium barbarum from different habitats by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry.

The leaves of Lycium barbarum (LLB) have been utilized as crude drugs and functional tea for human health in China and Southeast Asia for thousands of years. To control its quality, a rapid and sensitive ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry method was established and validated for the first time for simultaneous determination of 10 phenolic acids and flavonoids (including neochlorogenic acid, protocatechuic aldehyde, p-hydroxybenzoic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, rutin and kaempferol-3-O-rutinoside) in LLB. The separation was performed on an Acquity UPLC C18 chromatographic column (100 × 2.1 mm internal diameter, 1.7 μm particle size) with 0.1% formic acid in water (A)-acetonitrile (B) as the mobile phase under gradient elution. Multiple reaction monitoring mode was adopted to simultaneously monitor the target components. The developed method was fully validated in terms of linearity (r2  ≥ 0.9860), precision (RSD ≤ 6.58%), repeatability (RSD ≤ 6.60%), stability (RSD ≤ 6.17%), recovery (95.56-108.06%, RSD ≤ 4.64%) and limit of detection (0.021-0.664 ng/mL) and limit of quantitation (0.069-2.210 ng/mL), and then successfully applied to evaluate the quality of 64 batches of LLB collected from 41 producing areas in four different provinces of China. The results showed that the LLB, especially collected from Inner Mongolia regions, were rich in the phenolic acids and flavonoids. Rutin, kaempferol-3-O-rutinoside and chlorogenic acid are the predominant compounds contained in LLB. The above findings will provide helpful information for the effective utilization of LLB.