Analysis of Major Chemical Constituents in Jiuwei Decoction Based On Capillary Electrophoresis Coupled With Quadrupole Time-of-Flight Mass Spectrometry

Abstract

An analytical method for identifying the chemical constituents in the Chinese herbal combination Jiuwei decoction was established using capillary electrophoresis coupled with quadrupole time-of-flight mass spectrometry. Nine herbs were extracted with a 60:40 (v/v) ethanol/water solution to prepare the Jiuwei decoction. Electrophoretic separation was carried out using a 50 µm i.d., 125 cm bare fused silica capillary at a constant temperature of 25°C for sample injection. The chemical composition was analyzed and identified in both positive and negative ion modes. In the positive separation mode, a separation voltage of 30 kV was applied, with a 1% aqueous formic acid solution serving as the background electrolyte (BGE), along with a 50:50 (v/v) methanol/water solution containing 0.1% formic acid as the sheath liquid. In the negative separation mode, a separation voltage of −30 kV was employed, utilizing a 50 mM ammonium acetate solution (pH 9.0) as the BGE, combined with a 50:50 (v/v) methanol/water solution containing 5 mM ammonium acetate as the sheath liquid. The MassHunter Qualitative Analysis software (version 10.0) was utilized to identify 52 compounds based on accurate mass, isotope abundance, isotopic patterns, and fragmentation information. The data were compared with the Agilent Personal Compound Database and Library of traditional Chinese medicine (TCM), as well as multiple online databases (TCMSP, ChemSpider, PubChem, PubMed, and Web of Science) and relevant literature. The fragmentation pathways of representative compounds were also characterized. This study identified the chemical composition of Jiuwei decoction, providing a molecular basis for further exploration of its pharmacological effects and presenting a robust methodology for the compositional analysis of complex TCM mixtures.