Supercritical CO ₂ Fluid Extraction for the Identification of Compounds from Citrus reticulata Semen by Ultra-High-Performance Liquid Chromatography Combined with Q-Exactive Orbitrap Tandem Mass Spectrometry

Abstract

A rapid and simple method based on the coupling of supercritical fluid extraction and ultra-high-performance liquid chromatography combined with Q-Exactive Orbitrap tandem mass spectrometry (SFE-UHPLC-Q-Exactive Orbitrap-MS) detection for the identification of compounds from Citrus reticulata semen (CRS) was developed for the first time in this study. Through the optimization of the SFE parameters including extractive pressure, extractive temperature, and time, most of the compounds were successfully extracted at 50 °C, 33 MPa, and 2 h without an entraining agent, among which 32 compounds were successfully identified. Moreover, the operating conditions of UHPLC-Q-Exactive Orbitrap-MS were also optimized for the analysis of the SFE extracts, and the extracts in the CRS showed good separation performance in 20 min. A total of 28 compounds from the SFE extract were identified by comparing the standard sample together with full scan and related literature data, among which esters and flavonoids were the major compounds identified in the CRS extracts. In addition, 2 phenols, 2 aldehydes, 2 triterpenes, and 5 other compounds were identified. The SFE-UHPLC-Q-Exactive Orbitrap-MS method was successfully validated and applied for the identification of compounds from the CRS.