Computational-aided design of molecularly imprinted polymer for selective extraction of methadone from plasma and saliva and determination by gas chromatography

► A molecular modeling was used for design of molecular imprinted polymer for methadone. ► Calculations were carried out using DFT at B3LYP/6-31G+ (d, p) level and Gaussian 2003. ► The best monomer and porogen was MAA and acetonitrile, respectively. ► Distribution ratios (Kd) and imprinting factors (IF) of methadone were measured. ► The MIP was used for MISPE of methadone from plasma and saliva samples.