Kinetic Spectrophotometric Determination of Morphine in Pharmaceutical Samples

A new, sensitive, simple, inexpensive and fast kinetic spectrophotometric method was developed for the determination of trace amounts of morphine over the range of 12-60ng/mL. The method is based on the catalytic effect of morphine on the reaction of bromate and methylene bluein acidic media is reported. The reaction was monitored spectrophotometrically by 60 ng/ml measuring the decrease in absorbance of methylene blue at 665 nm with a fixed-time 0.5-2.5 min from initiation of the reaction. The detection limit is 0.8 ng/mL and relative standard deviation of 12and 52ng/mLmorphine for 6 replicate measurements was 1.50 and 0.87%respectively. The method 12 and 52 ng/ml was applied to the determination of morphine inpharmaceutical samples % respectively.