Product ion scans were collected using a normalized collision energy (CE) of 55 eV. Nitrogen served as the sheath, drying, and collision gases. MS parameters were optimized and set as: drying gas temperature at 150°C, dry gas flow rate at 15 L min -1 , sheath gas temperature at 225°C, sheath gas flow rate at 11 L min - 1 , nebulizer pressure at 30 psi, capillary voltage at 3500 V, and nozzle voltage at 1500 V.