Hair samples are extensively being used for detection of
drugs for forensic analysis purposes. The number of
drug-facilitated crimes has increased in recent years. According
to the National Crime Record Bureau (NCRB, India),
large numbers of cases have been registered under the NDPS
Act and cases pertaining to cannabis derivatives topped that
list. In various cases, complaints are made to police long
after any drugs would have been eliminated from blood or urine.
Once incorporated into the growing hair, the drug can be
detected long after it has been eliminated from more conventional
samples, such as blood and urine. Accordingly, hair
analysis has found applications in drug treatment program,
workplace testing, criminal justice cases and child custody disputes.23
This study was conducted with an objective to find out
the retention period of THC in human hair by GC–MS