Quantitative analysis of bioactive components in walnut leaves by UHPLC-Q-Orbitrap HRMS combined with QAMS.

Walnut leaves are rich in phenolic components with antibiotic and antioxidative effects. However, few studies have reported the quantitative analysis of active components in walnut leaf. In this study, a novel method for quantifying the active components in walnut leaves was developed by combining ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) with quantitative analysis of multi-components by a single marker (QAMS). In total, 13 bioactive components were analyzed by a single marker, quercetin. To evaluate the accuracy of this method, an auxiliary quantification method with 13 reference standards was established and validated. The standard method differences (SMDs) of the quantification results between QAMS and the auxiliary method were lower than 20%, indicating that the QAMS method can accurately determine the active components in walnut leaves. This method can provide a reference to address the absence of reference standards for analyzing other foods and herbs.