The capillary voltage was
set to 3.5 kV; the drying gas temperature was set to 300 C with
a gas flow rate of 8 L/min; the sheath gas temperature was set to
350 C with a gas flow rate of 11 L/min; and the nebulizer pressure
was set to 35 psig. For the LC–MS/MS analysis of anandamide,
collision energy was set to 20 eV.