RESUMO
Objective T o infer the frequency of dosage and m edication history investigate of the victim s in drug facilitated cases by the segm ental analysis of clonazepam in hair. Methods Freezing m illing un-der liquid nitrogen environm ent com bined w ith ultrasonic bath w as used as sam ple pretreatm ent in this study, and liquid chrom atography-tandem m ass spectrom etry w as used for the segm ental analysis of the hair sam ples collected from 6 victim s in different cases. T he concentrations of clonazepam and 7-am in-oclonazepam w ere detected in each hair section. Results C lonazepam and its m etabolite 7-am inoclon-azepam w ere detected in parts of hair sections from the 6 victim s. T he occurrence tim e of drug peak concentration w as consistent w ith the intake tim ing provided by victim s. Conclusion Segm ental analysis of hair can provide the inform ation of frequency of dosage and intake tim ing, w hich show s an unique evidential value in drug facilitated crim es.