摘要：Tropaeoline 00 anion was found to be extracted with morphine benzyl derivative as 1 : 1 complex in dichloromethane. The tropaeoline 00-dichloromethane-hydrochloric acid system gave a red color for morphine benzyl derivative, while in the absence of hydrochloric acid, a dichloromethane phase showed a yellow color. In this way, the spectrophotometric method was investigated for the determination of a small amount of morphine by solvent extraction. The recommended procedure is as follows. One ml of standard morphine hydrochloride solution (1.30×10-8-1.60×10-7mol/ml), 5ml of 3% sodium carbonate solution, 2 ml of solution of benzyl chloride (2.75×102μg/ml, 2.17×10-6mol/ml) in acetone, and 5 ml of acetone were taken into a 20 ml Erlenmeyer's flask, Refluxed on a water-bath for 15 min and acetone was evaporated. After cooling, the flask was shaken for 30 sec with 10 ml of dichloromethane. After separation of the two layers, take 5 ml of dichloromethane layer was taken into 10 ml of test tube and added 1 ml of solution of tropaeoline 00 (1.22mg/ml) and 2 ml of buffer solution (pH 3.5). The mixture was shaken for 3 min and centrifuged for 2 min at 3000 rpm. Two ml of dichloromethane layer was taken into a glass tube and added 0.5 ml of 10 % hydrochloric acid in methanol, the absorbance of the solution was measured at 543 nm using dichloromethane as a reference. The morphine is determined by measuring the absorbance of the extracts over a range from 1.30×10-8-1.60×10-7mol/ml (5-60μg/ml) at 543 nm. The determination of morphine is not interfered by the presence of the additive materials, such as metal ions, ammonium ion, glucose, lactose and L-leucine. But a small amounts of alkaloids gave a strong interference.
