Micromass zq ms

The preparative LC/MS system included a Micromass ZQ MS (Waters Corp.) and a fractionation system of 2,767 samples manager (Waters Corp.) with 2,998 PDA. The analysis protocol was similar to isolating and identifying antioxidant compounds by LC-DAD-ESI/MS. Furthermore, the fraction settings were adjusted to 78 maximum fractions and tubes per injection, 60 s for the solvent front delay, 10 s for the collector delay, and 60 s for the maximum fraction width. The ethyl acetate fraction from R. emodi was used at 200 mL per injection at a concentration of 50,000 ppm. The collected fractions were examined straight from collection tubes without any further liquid handling. The peak purity of collected fractions relative to the principal component was evaluated using relative peak areas in mass chromatograms.

The compounds present in R. emodi fractions were isolated following the method (Park et al., 2021 (link)) using Micromass ZQ MS (Waters Corp., Milford, MA, USA) and an Alliance e2695 high-performance liquid chromatography (HPLC) system (Waters Corp.) equipped with a 2998 photodiode array detector (PDA). In addition, the reversed-phase column YMC PACK ODS-AM (4.6×250 nm I.D., 5 m, YMC Co., Ltd., Kyoto, Japan) was used. The analysis was conducted at a flow rate of 1 mL/min in the detection wavelength range of 190∼600 nm (a representative wavelength of 254,350 nm) with a column heater set to 30°C. Trifluoroacetic acid in water (0.1%, phase A) and acetonitrile (phase B) were utilized as mobile phases. The pretreatment sample was evaluated using the following gradient conditions: a gradient of 10∼30% phase B over 25 min, 30% phase B for 5 min, a gradient of 30∼10% phase B for 3 min, and a final wash with 10% phase B for 7 min. The MS analysis was performed with an ESI source in positive ionization mode. The MS parameters were adjusted at 30 V cone voltage, 120°C source temperature, 350°C desolvation temperature, and 500 L/h desolvation N₂ gas flow. In full scan mode, the molecular weight range was 100∼1,200 m/z.