title: Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method.
abstract: A sensitive and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy methamphetamine in hair samples. Segmented hair (10 mg) was incubated in 2M sodium hydroxide (80°C, 10 min) before liquid-liquid extraction with isooctane followed by centrifugation and evaporation of the organic phase to dryness. The residue was reconstituted in methanol:formate buffer pH 3 (20:80). The total run time was 4 min and after optimization of UHPLC-MS/MS-parameters validation included selectivity, matrix effects, recovery, process efficiency, calibration model and range, lower limit of quantification, precision and bias. The calibration curve ranged from 0.02 to 12.5 ng/mg, and the recovery was between 62 and 83%. During validation the bias was less than ±7% and the imprecision was less than 5% for all analytes. In routine analysis, fortified control samples demonstrated an imprecision <13% and control samples made from authentic hair demonstrated an imprecision <26%. The method was applied to samples from a controlled study of amphetamine intake as well as forensic hair samples previously analyzed with an ultra high performance liquid chromatography time of flight mass spectrometry (UHPLC-TOF-MS) screening method. The proposed method was suitable for quantification of these drugs in forensic cases including violent crimes, autopsy cases, drug testing and re-granting of driving licences. This study also demonstrated that if hair samples are divided into several short segments, the time point for intake of a small dose of amphetamine can be estimated, which might be useful when drug facilitated crimes are investigated.
authors.affiliation: Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, SE-58758, Linköping, Sweden.
authors.forename: Gerd
authors.initials: G
authors.lastname: Jakobsson
authors.forename: Robert
authors.initials: R
authors.lastname: Kronstrand
mesh_terms: D000662:Amphetamines / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000662:Amphetamines
keywords: LC-MS-MS; amphetamines; forensic; hair; segmental analysis