SENSITIVE SYNCHRONOUS SPECTROFLUOROMETRIC METHODS FOR THE DETERMINATION OF NAPROXEN AND DIFLUNISAL IN SERUM

The interaction of diflunisal and naproxen with several surfactants wa s studied. Spectrofluorimetric methods were developed for the determin ation of both drugs in sodium dodecylsulfate micellar medium. The mixt ure of these drugs was resolved by synchronous fluorescence spectromet ry using two scans, At Delta lambda = 20 nm, only naproxen yields a de tectable signal that is unaffected by the presence of diflunisal, At D elta lambda = 110 nm the signal of diflunisal is not influenced by the presence of an up to 3-fold excess of naproxen. Mixtures containing n aproxen/ diflunisal in ratios from 50:1 to 1:50 were analyzed with goo d results, The linear calibration ranges of both drugs were ca 0.02-2. 0 mu g mL(-1). The method has satisfactorily been applied to a mixture of both drugs in serum.