Time resolved analysis of quetiapine and 7-OH-quetiapine in hair using LC/MS–MS

•Quetiapine and its metabolite 7-OH-quetiapine can be detected in hair by LC–MS/MS.•Hair testing is a valuable tool for the detection of drugs, including quetiapine.•Detection of quetiapine in hair can be used for e.g., therapeutic drug monitoring.

Hair analysis is a powerful tool for retrospective drug analysis and has a wide application window. This article describes the simultaneous determination and quantification of the short-acting atypical antipsychotic drug quetiapine and its main metabolite 7-OH quetiapine in hair. A sensitive and accurate method for the determination of these two compounds was developed using high-performance liquid chromatography coupled to tandem mass spectrometry detection (LC–MS/MS). The method was applied to 10 real case samples. For five patients, a time resolved hair analysis was done. Results varied from 0.35 ng/mg to 10.21 ng/mg hair for quetiapine and from 0.02 ng/mg to 3.19 ng/mg hair for 7-OH-quetiapine.