Radioimmunological determination of cocaine in human hair

Summary A simple procedure for the determination of cocaine in human hair was described. After washing hair samples were crushed in 0.1m HCl and incubated overnight at 45°C. The acid extracts were neutralized with 1m NaOH. Phosphate buffer (pH 7.4) was added to the extracts. The cocaine concentrations were measured by radioimmunoassay. Detection in hair was achieved in all hair samples obtained from cocaine users. This method appears to be suitable for the routine determination of cocaine.