A liquid chromatography-tandem mass spectrometry (LC-MSMS) target screening in 50mg hair was developed and fully validated for 35 analytes (Δ9-tetrahidrocannabinol (THC), morphine, 6-acetylmorphine, codeine, methadone, fentanyl, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine,