Methanol and water lc ms grade

THC, 11-OH-THC, THCCOOH, CBD, CBN, THC-d₃, 11-OH-THC-d₃, THCCOOH-d₉, CBD-d₃, CBN-d₃, and THCCOOH-glucuronide-d₃ were purchased from Cerilliant (Round Rock, TX, USA). CBG was from Restek (Bellefonte, PA, USA), THCV was from RTI International (Research Triangle Park, NC, USA), and THCVCOOH and THC-glucuronide were acquired from ElSohly Laboratories (Oxford, MS, USA). Ammonium acetate and acetonitrile (LC-MS grade) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Methanol and water (LC-MS grade) and formic acid (ACS-grade) were from Fisher Scientific (Fair Lawn, NY, USA). WAX-S tips (1 mL tip containing 20 mg resin and 40 mg salt) were purchased from DPX Labs (Columbia, SC, USA). Chromatography was performed on a Kinetex® C₁₈ column (Phenomenex® Inc., Torrance CA, USA; 2.1 mm × 50 mm, 2.6 μm) combined with a SecurityGuard™ C₁₈ guard column (4 × 2.0 mm).