Quality control samples were prepared by diluting appropriate amounts of psilocybin (Supelco Cerilliant 99.99%, 1.000 mg/mL in 50:50 H2O:MeCN) and Psilocin (Supelco Cerilliant 99.4%, 1.000 mg/mL in MeCN) certified reference materials (CRM). These samples were used to validate the analytical method for performance. Precision was measured through triplicate injections of individual CRM samples (50.0 ppm) which were quantified against pure psilocybin (Psygen Labs, 99.977%) calibrant solutions prepared in HPLC grade water.