Materials
The mTOR inhibitor PP242 (torkinib, purity 97.75%) was purchased form MedChemExpress (NJ, USA). Internal standards (ISs), reserpine, and 1-Hexadecanoyl (d31)-2-(9Z-octadecenoyl)-sn-glycero-3-phosphocholine (PC(16:0/18:1)-d31) and arachidonic acid-d8 were purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO. USA) and Avanti Polar Lipids (Alabaster, AL, USA), respectively. Formic acid, ammonium acetate and 10% neutral buffered formalin solution were purchased from the Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). Ultrapure water (18.2 MΩ.cm) was generated using a Milli-Q apparatus from Millipore (Milford, MA, USA). All other chemicals were of highest analytical grades and HPLC grade organic solvents were used for the preparation of mobile phases and supplied by Burdick & Jackson (SK chemicals, Ulsan, Korea).