Uplc q orbitrap hrms

Ultra-high-performance liquid chromatography coupled with Q-Orbitrap (UPLC-Q-Orbitrap HRMS, Thermo Fisher Scientific, Waltham, MA, USA) was previously applied to speculate the components of SCE [7 (link)]. Standard identification of abietic acid (HPLC ≥ 98%, Solarbio, Beijing, China) is essential for the rigor of this present study. The sample (200 mg) was dissolved in methanol solution (methanol: water, 8:2, V/V; 1 mL) before centrifugation at 20,000× g for 10 min. Subsequently, impurities were removed using a 0.22-µm PES membrane. Abietic acid was diluted with methanol and sonicated for 5 min to obtain a standard stock solution with a concentration of 20 µg/mL. The mass spectrometry was performed via ESI with positive and negative ion switching scanning. For chromatography, it was accomplished according to gradients of aqueous and organic phases. More details can be obtained in our previous study [8 (link)]. The quantification of AA was determined using peak area calculation.

The formula of TCM decoction for colon dialysis consists of the following ingredients: Rheum officinale Baill (15 g, #230501), Astragalus membranaceus Bunge (45 g, #Y230101-2), Salvia miltiorrhiza Bunge (45 g, # 230524), Oyster shell (45 g, #230415), Ligusticum chuanxiong Hort (25 g, #230326), and Carthamus tinctorius L. (15 g, #230401). All Chinese medicinal herbs were provided by Sichuan Traditional Chinese Medicine Herbal Pieces Co., Ltd. The appropriate amount of sample powder was taken and extracted, filtered to obtain the sample solution. The sample solution was analyzed by UPLC-Q-Orbitrap-HRMS (Thermo Fisher Scientific, United States). The conditions as follows:

• Liquid Chromatography Conditions

Column: Thermo Scientific AccucoreTM C18 column (100 mm × 3 mm, 2.6 μm); Injection volume: 3 μL; Mobile phase: 0.1% formic acid water (A) - acetonitrile (B); Flow rate: 0.25 mL/min; Column temperature: 30°C; Gradient elution: (0–2 min, 2% B; 2–8 min, 2% →75% B; 8–11.0 min, 75% →75% B; 11.0–11.5 min, 75% →2% B; 11.5–15.0 min, 2% B).

• Mass Spectrometry Conditions

The electrospray ionization (ESI) source was used for simultaneous detection in positive and negative ion modes. The spray voltage was set to 5500 V (+) and 4500 V (-). The nebulizing gas pressure was maintained at 0.40 MPa, and the ion source temperature was set to 550°C.