Recent improvements in forensic hair analysis for illicit drugs

This review summarizes technical and administrative improvements in forensic hair analysis for methamphetamine (MA) and designer drugs, recently developed by the present authors' team. These improvements include the establishment of three types of screening methods, and a column-switching liquid chromatographic-mass spectrometric (LC-MS) method for determining such drugs and their metabolites to serve as an alternative confirmation technique. The screening methods include ion mobility spectrometry-based, enzyme multiplied immunoassay technique (EMIT)-based, and immunochromatography-based methods. The column-switching LC-MS method proved to be effective in clearly determining MA and its metabolites, amphetamine and p-hydroxy-MA, which provides indisputable proof of MA intake. Quality assurance measures in forensic hair analysis, such as semiquantitative cross-checkings between the results of different analyses, are also discussed.