E-cigarette fluids were extracted from the pods and devices, and 50 μL was dissolved in 0.95 mL of isopropyl alcohol (Fisher Scientific, Fair Lawn, NJ). Chemical analysis was performed with an Agilent 5975C GC/MS system (Santa Clara, CA) using internal standard-based calibration procedures and methods previously described in detail.6 (link),33 (link) The method analyzes 180 flavor chemicals plus nicotine.