Synthesis and characterization of molecularly imprinted polymers for the selective extraction of cocaine and its metabolite benzoylecgonine from hair extract before LC-MS analysis

► High selectivity of a MIP prepared using methacrylic acid as monomer. ► Selective extraction procedure of cocaine and benzoylecgonine on MIP. ► Binding capacity of the MIP of about 9 μmol g−1. ► Efficient clean-up of a hair extract using the MIP before LC/MS analysis.