Violence under the inﬂuence of methylphenidate as determined by hair analysis
Pascal Kintz · Marion VillainReceived: 11 March 2010 / Accepted: 30 March 2010 / Published online: 12 May 2010 © Japanese Association of Forensic Toxicology and Springer 2010
Abstract A 26-year-old woman under the inﬂuence ofalcohol assaulted another person at a party in late November 2008. Afterward, she claimed that her drink was spiked with Ritalin, which would account for her bizarre behavior. Neither urine nor bloodwas sampled, because of the elapsed time after the incident. Hair was collected in late February 2009 and sent to our laboratory for methylphenidate testing. The hair strand was decontaminated twiceusing methylene chloride and then segmented. Each segment was cut into small pieces and about 30 mg was incubated in an ultrasonic bath for 3 h in buffer solution at pH 5.5 in the presence of 100 ngof 3,4-methylenedioxymethamphetamine (MDMA)-d5 used as internal standard (IS). Each mixture was neutralized with NaOH and extracted with hexane/ ethyl acetate (90:10). After evaporation, the residuewas reconstituted in 200 μl of acetonitrile/formate buffer (5:95). Each sample was subjected to liquid chromatography-tandem mass spectrometry (LC-MS-MS) with a gradient elution of acetonitrile andformate buffer. For both methylphenidate and MDMA-d5, detection was performed with two product ions each (m/z 234 to 84 and 56 for methylphenidate; m/z 199 to 135 and 165 for IS). The method showed alinear response from 0.5 to 500 pg/mg with a limit of quantitation of 0.5 pg/mg. Hair collection was made 3 months after the incident, so it was decided that the hair be analyzed in three 4-cmsegments. Methylphenidate was detected only in the proximal segment at 1.0 pg/mg, while the result was negative in the other two segments. These results support
the suggestion of a single exposure to...