In this study, an effective and relatively simple analytical procedure to determine morphine in urine samples were developed. The procedure includes: (1) liquid-liquid extraction of urine samples with a solvent mixture of chloroform and isopropanol (v/v = 9 : 1) at pH = - . This extraction technique yielded a high recovery in a range from 80% to 85% for morphine, and (2) qualification of morphine in the final extracts by using a Gas Chromatography equipped with a flame ionization detector (FID). The developed analytical procedure was then applied to analyze morphine in authentic urine samples taken from drug users. Morphine concenstrations in these urine samples ranged from to µg/l.
