RESUMEN
OBJECTIVES@#To establish a rapid determination method with LC-MS/MS for cocaine and its metabolite benzoylecgonine in hair.@*METHODS@#Deuterated internal standards （cocaine-D₃ and benzoylecgonine-D₈） were added to the decontaminated hair. After the extraction by ultrasonication with methanol, the compounds were separated by the Restek Allure PFP propyl column, and cocaine and benzoylecgonine were simultaneously analysed in multiple reaction monitoring mode.@*RESULTS@#The cocaine and benzoylecgonine in hair showed a good linearity in the range of mass fraction between 0.02 and 10.00 ng/mg with the limits of detection of 0.01 ng/mg.@*CONCLUSIONS@#The developed method is simple and rapid with a good selectivity, which is suitable for the determination of cocaine and its metabolite benzoylecgonine in hair.