SELECTIVE DETERMINATION OF NAPROXEN IN THE PRESENCE OF NONSTEROIDAL ANTIINFLAMMATORY DRUGS IN SERUM AND URINE SAMPLES USING ROOM-TEMPERATURE LIQUID PHOSPHORIMETRY

A very simple, rapid and highly sensitive method is described for dete rmining naproxen in serum and urine. This method is based on room temp erature phosphorescence of naproxen in sodium dodecylsulphate micelles , with thallium(I) providing the external heavy atom and sodium sulphi te acting as the oxygen scavenger. Under the optimum experimental cond itions, the range of application is 0.09-4.5 mu g ml(-1) and the limit of detection is 0.03 mu g ml(-1). The most relevant characteristic of this method is its great selectivity, e.g. naproxen can be determined in the presence of other nonsteroidal anti-inflammatory drugs (NSAIDs ). The clinical applicability of this procedure has been tested, analy sing naproxen in serum and urine samples. The analytical recoveries an d inter- and intra assay precision data obtained demonstrate the usefu lness of this procedure when used with very complex samples. (C) 1998 Elsevier Science B.V. All rights reserved.