6540 ultra high definition accurate mass q toflc ms

For the profiling of LME using UPLC-TOF-MS, 1 g was extracted using 70% EtOH in an ultrasonic bath (Branson ultrasonic corporation, Danbury, CT, USA) for 1 h. After filtering and centrifugation for 15 min at 12,000× g, the clear supernatant was used for UPLC-qTOF-MS analysis. The UPLC-qTOF-MS analysis of the extract was conducted under the exact conditions reported in [10 (link),18 (link)]. The used HSS T3 column (100 × 1.0 mm, 1.8 m particle size; Waters) was installed on an ACQUITY UPLC system (Waters, Milford, MA, USA) equipped with a 6540 Ultra-High-Definition (UHD) Accurate-Mass Q-TOFLC/MS (Agilent, Palo Alto, CA, USA), coupled to an ESI interface, and was operated in a positive or negative ion mode.

UPLC-MS analysis was performed following exact conditions described in Farrag, et al. [8 (link)]. Briefly, dried finely pulverized L. nudicaulis specimen (10 mg) was extracted by adding 2 mL 100% MeOH, containing 10 μg/mL⁻¹ umbelliferone as an internal standard sonicated for 20 min with frequent shaking, then centrifuged at 12,000× g for 10 min to remove debris. The filtered extract through a 22-μm filter (about 500 μL) was subjected to solid-phase extraction using a C₁₈ cartridge as previously described [114 (link)]. L. nudicaulis extract (2 μL) was loaded on HSS T3 column (100 × 1.0 mm, particle size 1.8 μm; Waters) installed on an ACQUITY UPLC system (Waters, Milford, MA, USA) equipped with a 6540 Ultra-High-Definition (UHD) Accurate-Mass Q-TOFLC/MS (Agilent, Palo Alto, CA, USA) coupled to an ESI interface, operated in positive or negative ion mode following conditions described in 113. Characterization of compounds was performed by the generation of the candidate formula with a mass accuracy limit of 10 ppm, and also considering RT, tandem MS2 data, and searching reference literature and the Phytochemical Dictionary of Natural Products Database. Peaks were detected in both negative and positive (deviating values in brackets) ion modes.