Immunological and chromatographic follow-up of 11-nor-carboxy-delta9 tetrahydrocannabinol in urine of single and multiple hashish smokers

The authentic COOH-THC was used as a reference in TLC and HPTLC study of the urinary excretion pattern of cannabis metabolites. Hemagglutination inhibition testing for COOH-THC on urine was directly carried out alongside with the chromatography. The results revealed that after occasional smoking of a single hashish cigarette urine samples will be positive for 1-3 days. After chronic smoking of several hashish cigarettes 2-3 times a week, the urine may be positive for 1-2 weeks after the last dose. After heavy daily smoking for more than one month, the urine samples may be positive for 1-3 months after the last dose