DETERMINATION OF MORPHINE AND RELATED ALKALOIDS IN CRUDE MORPHINE, POPPY STRAW AND OPIUM PREPARATIONS BY MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY

A rapid method for the determination of morphine and related alkaloids in crude morphine, poppy straw and opium preparations by micellar ele ctrokinetic capillary chromatography (MEKC) has been developed. Morphi ne, codeine, thebaine, oripavine, papaverine, narcotine, narceine, cry ptopine and salutaridine were separated in less than 10 min using a 70 cm x 50 mu m I.D. uncoated fused-silica capillary column with a buffe r consisting of 10% dimethylformamide, 90% 0.05 M cetyltrimethylammoni um bromide, 0.01 M potassium dihydrogen orthophosphate, 0.01 M sodium tetraborate, pH 8.6. An applied voltage of -25 kV and a temperature of 28 degrees C gave the best separation of the alkaloids. Pholcodine wa s used as the internal standard. The compounds were detected by UV at 254 nm. The levels of morphine and related alkaloids determined by MEK C were in good agreement with those determined by high-performance liq uid chromatography (HPLC). The coefficients of variation for area calc ulation (%C.V.) for multiple sample and standard injections by MEKC we re slightly greater than for HPLC but were still acceptable (morphine content of poppy straw: %CV. MEKC 1.7%, %CV. HPLC 0.3%).