Plasma metabolomics analysis
RESOLUTION
Plasma metabolomics was performed with the Agilent ZORBAX Rapid Resolution High Definition Extend-C18 (2.1 × 150 mm, 1.8 µm) and ZORBAX Extend Fast Guards for UHPLC. Ion paring (IP) stock solution was prepared by mixing GC-grade 450 ml methanol, 35.8 ml tributylamine (TBA) and 12.9 ml acetic acid. Solution A was prepared with 1,000 ml of HPLC-grade water, 1,034 µl deactivator and 34.25 ml IP stock solution. Solution B was prepared with 1,000 ml of HPLC-grade methanol, 1,034 µl deactivator and 34.25 ml IP stock solution. Solvent A was 97% water and 3% methanol with 15 mM acetic acid and 10 mM TBA at a pH of 5. Solvent C was 15 mM acetic acid and 10 mM TBA in methanol. The washing solvent D was acetonitrile. The LC system seal washing solvent was 90% water and 10% isopropanol. The needle washing solvent was 50% methanol and 50% water. The LC gradient profile was: at 0.25 ml min