A valid and reliable method based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry using electrospray ionization was established to identify chemical constituents in the ethanol extract of pigeon pea leaves. A total of 58 compounds were detected both in positive and negative modes. Among them, 42 compounds, including 16 flavones, 1 flavonol, 5 flavanones, 9 isoflavones, 1 coumarin, 1 lactone, 6 stilbenes, 2 chalcones, and 1 other compound, were unambiguously identified or tentatively assigned in view of the retention time, the molecular formula, as well as the fragmentation patterns. Moreover, eight sets of isomers were differentiated by the ion trap mass spectrometry based on the fragment ion differences or the abundance differences of the same fragment ions. The energy-resolved mass spectrometry in light of the relative abundance of characteristic fragment ions was adopted in the study.

中文翻译：

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LC-MS法对木豆（Cajanus cajan L.）叶的成分鉴定和异构体分化

建立了一种基于超高效液相色谱与四极杆飞行时间质谱联用电喷雾电离的有效可靠方法来鉴定木豆叶乙醇提取物中的化学成分。在阳性和阴性模式下共检测到 58 种化合物。其中，42种化合物，包括16种黄酮、1种黄酮醇、5种黄烷酮、9种异黄酮、1种香豆素、1种内酯、6种芪、2种查耳酮和1种其他化合物，从保留时间、分子式，以及碎片模式。此外，基于碎片离子差异或相同碎片离子的丰度差异，通过离子阱质谱法区分了八组异构体。