2.3.3. Plasma Lipidomic Profiling
COLD
Venous plasma samples collected at three time points (t1–t3) were used for lipidomics analysis using ultra-high-performance liquid chromatography–mass spectrometry (UPLC-MS/MS). The order of the plasma samples was randomized prior to extraction and instrumental analyses to minimize the influence of signal fluctuations. Pooled samples were used as quality controls throughout the analysis to verify the reproducibility. Details of instrumental analysis and data processing procedures including lipid extraction, peak detection, and lipid annotation are presented in In brief, 100 μL of plasma sample was properly mixed with 800 μL cold methyl tert-butyl ether and then mixed with 240 μL methanol. The mixture was vortexed for 30 s, sonicated at 4 °C for 20 min, and then centrifuged at 14,000× 