Volume 23, Issue 3 (July 1978)
Recovery of Morphine from Biological Samples by Hydrolysis and Solvent Extraction
Quantitative recovery of drugs from biological samples is important when a response is to be related to the amount of drug present in a tissue sample. Morphine is one drug of interest in this regard because of its widespread use and its chemical peculiarities. Its relatively low dosage, amphoteric nature, and metabolism to a water-soluble product, 3-morphine monoglucuronide [1,2], make morphine relatively difficult to analyze in biological samples. Most quantitative analytical schemes of analysis require that the glucuronide be cleaved to free morphine for extraction into an organic solvent. Acid hydrolysis  and enzymatic cleavage  are the most popular methods for freeing the morphine. We report here a study of the recoveries of radioactively tagged morphine from biological samples of morphine-treated dogs by using hydrolysis and solvent extraction. It is possible to recover more than 90% of the morphine contained in a sample with acid hydrolysis and about 80% with enzymatic cleavage.