Qualitative analysis of chemical components in Farfarae Flos and honey-processed Farfarae Flos by UPLC-Q-TOF-MS coupled with two-dimensional GC×GC-TOF-MS.

Farfarae Flos (FF) has long been recognized as a staple in traditional Chinese medicine for treating respiratory ailments, with its use documented in classical medical texts. Its processed form, honey-processed Farfarae Flos (PFF), undergoes a specific honey-processing treatment that alters its chemical composition. Despite its historical significance, the complex chemical profiles of FF and PFF remain inadequately explored. This study enhances analytical methodologies by combining Ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) with two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) to comprehensively profile the chemical compositions of both FF and PFF. A total of 78 components were identified from FF, including both positive and negative ion modes, while 87 components were detected in PFF. Detailed fragmentation patterns were analyzed, revealing unique fragments for several key compounds. GC×GC-TOF-MS analysis identified 324 volatile constituents in FF, whereas PFF contained 328 distinct compounds, all compared against an extensive TCM library spanning various chemical classes. Using the relative odor activity value (ROAV) to quantify flavor contributions, aldehydes emerged as dominant key flavor compounds while ketones and organoheterocyclic compounds acted as secondary contributors, and most alcohols/esters had negligible effects. This work represents the first thorough cataloging of the primary chemical constituents in FF and PFF, leveraging the integration of UPLC-Q-TOF-MS and GC×GC-TOF-MS techniques. The systematic identification and characterization of these constituents provide a solid analytical framework for future efforts in quality control and standardization. The findings not only deepen the scientific understanding of FF and PFF but also establish a foundational methodology for the evaluation and regulatory standardization of herbal medicines.