AUTOMATED KINETIC SPECTROFLUOROMETRIC METHOD FOR THE DETERMINATION OFMORPHINE IN URINE

The continuous addition of reagent technique was used with spectrofluo rimetric detection for the kinetic determination of morphine in urine samples. The method thus developed is based on the oxidative dimerizat ion of morphine to fluorescent pseudomorphine by potassium hexacyanofe rrate(III) in a basic medium. The optimum pH, oxidant concentration an d instrumental variables were determined. The method permits the sensi tive determination of morphine over a wide concentration range (1 5-92 5 ng ml-1) with high precision (relative standard deviation almost-equ al-to 2%), selectivity and sample throughput (48 samples h-1). A novel sorption-desorption procedure was used to isolate morphine from whole urine, which provided recoveries of between 85 and 100%. The results showed the usefulness of the proposed method for controlling a wide va riety of medicinal problems (e.g., therapeutic, overdose and doping an alysis).