Evaluation of cocaine, amphetamines and cannabis use in university students through hair analysis: preliminary results.

The evaluation of drug abuse in a defined population was performed through toxicological hair analysis. Hair samples from university students ranging from 18 to 25 years of age were anonymously collected and screened for cocaine, amphetamines and cannabinoids by radioimmunoassay (RIA). Positive results (cut-off values adopted were 2 ng/mg for cocaine and amphetamines and 0.5 ng/mg for cannabinoids) were confirmed by GC/MS. Preliminary results showed 19% of positive results for cocaine on 200 samples analysed. No confirmed positive results were obtained for amphetamine analysis. RIA technique demonstrated its unsuitability for cannabinoids preliminary screening on hair, giving a high percent of false positive results