Feasibility of rat hair as a quality control material for the determination of methamphetamine and amphetamine in human hair

A quality control material (QCM) is a necessity in hair drug analysis, but it is not always easy to have an authentic hair sample containing various target drugs and metabolites. In the present study, the feasibility of rat hair as a QCM was examined for its application in the determination of methamphetamine (MA) and amphetamine (AP) in human hair. MA was administered to lean Zucker rats, from which only pigmented hair was collected for the preparation of a QCM. The rat hair was then washed, homogenized and finally bottled. Both homogeneity and stability were examined in order to demonstrate the suitability of rat hair as a QCM in hair drug analysis. The concentrations of MA and AP in each bottle were determined using extraction with 1% HCl in methanol at 38°C followed by gas chromatography/mass spectrometry after derivatization with trifluoroacetic anhydride. Furthermore, the prepared QCM was used in an inter-laboratory quality assurance program. In the homogeneity test, no significant difference was observed between bottles of the QCM. The statistical results also showed no significant trends in stability for three months at room temperature. An inter-laboratory quality assurance program was also performed successfully using this material. Thus, rat hair will be useful as an alternative QCM sample for the determination of a variety of drugs and their metabolites in human hair.