*2.1. Reagents*

Acetonitrile (ACN), isopropanol (IPA), chloroform (CHCl3), ethanol, methanol (MeOH), and ammonium acetate were obtained from Fisher Scientific, Inc. (Pittsburgh, PA, USA). All solvents used as UPLC mobile phases or for lipid extraction were chromatographic grade. Other chemicals were of analytical grade and purchased from Sangon Biotechnology Co., Ltd. (Shanghai, China). Ultrapure water from a milli-Q water purification system (Millipore, Bedford, MA, USA) was used for lipidomics.
