Rapid quantitative analysis of adulterant Lonicera species in preparations of Lonicerae Japonicae Flos

Lonicerae Japonicae Flos is often adulterated with Lonicerae Flos, which is derived from the other four Lonicera species, in both the crude drug and Lonicerae Japonicae Flos preparations. We proposed a methodology for the quantitative analysis of adulterant Lonicerae Flos in Lonicerae Japonicae Flos preparations. Taking macranthoidins A, B, dipsacoside B (saponins), sweroside (iridoids), and luteolin-7-O-d-glucoside (flavonoids) as markers, a method of ultra high performance liquid chromatography with triple quadrupole mass spectrometry was employed to determine their amounts in Lonicerae Flos, Lonicerae Japonicae Flos, and Lonicerae Japonicae Flos preparations. The proportion of adulterant Lonicerae Flos in Lonicerae Japonicae Flos preparations was estimated based on the saponin contents of Lonicerae Japonicae Flos and Lonicerae Flos. All analytes separated under isocratic elution in 12 min with acceptable linearity, precision, repeatability, and accuracy. Lonicerae Japonicae Flos was easily distinguished from Lonicerae Flos by the total amount of saponins (0.067 and > 45.8 mg/g for Lonicerae Japonicae Flos and Lonicerae Flos, respectively). Eighteen of twenty one Lonicerae Japonicae Flos preparation samples were adulterated with Lonicerae Flos in proportions of 11.3-100%. The developed ultra high performance liquid chromatography with triple quadrupole mass spectrometry method could be used for the identification of Lonicerae Japonicae Flos and the four species of Lonicerae Flos and for the analysis of Lonicerae Japonicae Flos preparations adulterated with Lonicerae Flos.