published the pioneering report on using RIA to detect morphine in the hair of heroin abusers. Today, chromatographic procedures, especially those coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS), represent the gold standard for the identification and quantification of drugs in hair, owing to their higher sensitivity and specificity.Hair analysis is now routinely used as a tool for detection of xenobiotics (drugs of abuse, pharmaceuticals, environmental contaminants, doping agents, etc.) in forensic science, traffic medicine, occupational medicine, and clinical toxicology.This paper summarizes and discusses some applications and methods used in hair analysis.
| BIOLOGY OF HAIRHair is a product of differentiated organs in the skin of mammals composed of protein (65-95%, keratin essentially), water (15-35%), lipids (1-9%), and minerals (<1%). The hair shaft consists of an outer cuticle that surrounds the cortex. The hair shaft develops in a follicle closely associated with the sebaceous and apocrine glands. The growth of hair occurs in cycles, alternating between periods of growth (anagen phase) and periods of quiescence (catagen and telogen phases). About the 1 million hair follicles of the adult scalp, approximately 85% of the hair is in the growing phase and the remaining 15% is in a quiescent stage. Hair is produced during 4-8 years for head hair (<6 months for nonhead hair) at a rate of approximately 0.22-0.52 mm/day or 0.6-1.42 cm/month for head hair. The growth rate depends on the type of hair, physiological factors, and the anatomical location (