COMPARISON OF DIFFERENT EXTRACTION PROCEDURES FOR DRUGS IN HAIR OF DRUG-ADDICTS

We have tested several solvents for the decontamination of control hai r contaminated by cocaine. Methylene chloride was the most efficient s olvent, eliminating more than 60% of contaminating cocaine. Two washes were used, additional washes were not effective in removing more coca ine, Sixteen hair and three pubic hair samples obtained from drug abus ers were tested by different extraction procedures: acid, alkaline and enzymatic hydrolyses and extraction by methanol. This study revealed that acid and enzymatic hydrolyses gave higher extraction recoveries f or drugs than methanolic extraction, After alkaline hydrolysis and met hanolic extraction, extracted samples were dirty and the chromatograms obtained showed an important interfering background, We concluded tha t acid hydrolysis is the extraction method of choice.