Development and validation of a rapid ultra-high performance liquid chromatography diode array detector method for Verbena officinalis L.

This study presents a fast and validated ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method for the simultaneous determination of the major compounds in Verbena officinalis L. (Verbenaceae), a medicinal plant listed in the European, British, and, Chinese Pharmacopoeias. In order to get reference substances, nine compounds, belonging to iridoids, flavonoids, and phenyl-propanoid glycosides, were isolated from the herb extract. Two of them, namely cistanoside D and leucosceptoside A, were found in this plant species for the first time. Chromatographic separation was achieved in less than 7 min on a Kinetex 1.7 u XB-C18 (50 x 2.10 mm) column by using a solvent gradient of water-acetonitrile modified with 0.1% formic acid. Method validation confirmed the assays sensitivity, linearity (R-2 >= 0.997), precision (intraday precision <= 1.71%; interday precision <= 1.46%) and accuracy (recovery rates between 93.9% and 108.8%) for the quantitative analysis of the eight selected marker compounds. Identity and peak purity of the analytes was confirmed by coupling the UHPLC instrument to a quadrupole time-of-flight mass spectrometer via an electrospray ionization interface (ESI-QTOF-MS) operating in the negative ionization mode. Finally, the applicability of the developed UHPLC-DAD method was successfully proven for the sensitive quantitation of the major compounds in Verbena herb extracts, thereby providing a reliable tool for its rapid quality control. (C) 2018 Elsevier B.V. All rights reserved.