Agilent 1290 infinity liquid

To analyze the content of ellagic acid in rat plasma, an Agilent 1290 Infinity liquid chromatography system, equipped with Agilent 6530 Q-TOF mass spectrometric system (Agilent Technologies, USA) was used in this study.
An Infinitylab EC-C 18 column (2.10 mm × 100 mm, 2.7 μm) (Agilent, USA) with a gradient elution was applied to conduct the separation. The sample injection volume was 20 μL and the flow rate was 0.2 mL min -1 . The column temperature was set at 30 °C and the UVdetection wavelength was 254 nm. The mobile phase was composed of acetonitrile (A) and 0.1 % formic acid containing 10 mmol L -1 ammonium acetate (B). The solvent gradient program of UHPLC analysis is shown in Table I.
The MS detection was performed on a Q-TOF mass spectrometer with ESI source in the negative ionization mode. The optimal MS parameters were as follows: mass spectrum scanning range: m/z 100~1200; nebulizer gas (nitrogen) temperature: 350 °C; nitrogen flow: 11 L min -1 ; nebulizer gas pressure: 50 psi; capillary voltage: 4000 V. The selected ionization pairs (m/z) of ellagic acid and gallic acid were 301.2 ([M-H] -) and 169.1 ([M-H] -), respectively.

All samples were analyzed using a LC-MS on Agilent 1290 infinity liquid chromatograph (Agilent Technologies, Wilmington, DE), coupled with an Agilent 6460 triple quadruple mass spectrometer. Separation of compounds were achieved using reverse-phase HPLC, with a Merck C-18 column of particle size 3 µm (5.5 cm length and i.d. of 4.6 mm) at 25ºC, and equilibrated with 90% solvent A (0.1% formic acid in MiliQ water) and 10% solvent B (0.1% formic acid in MeOH). A flow rate of 0.6 mL per min with a linear gradient was used as follows: 10% solvent B for 4 min, 80% solvent B over the course of 3.2 min, and 10% solvent B for 2.8 min. The total run time was 14 min, including a 5 min equilibration time.
The compounds were ionized using ESI + jet stream ion mode with the QQQ analyzer. The parameters of ion source were set as follows: capillary voltage at 4500 V, sheath gas flow at 8 L per min, fragmentor voltage 135 V, gas temperature at 350ºC, gas flow at 8 L per min, and nebulizer gas at 40 psi and detector used was MCP Microchannel Plate detector, while blank used after each sample of composition 50% MeOH + 50% MiliQ water.