An Ion Selective Electrode Study: Naproxen (NA) Quantification in Pharmaceutical Formulations

Abstract

AbstractThis study presents fabrication, characterizations and application of an ion‐selective electrode based on naproxen‐sodium tungstate (NA‐ST) ion pairs as a sensor for the quantification of naproxen in a number of pharmaceutical formulations. The ISE is made of the sensor (electrochemical active species or ion pairs) as well as polyvinyl chloride (PVC) and dibutyl phthalate as supporting and plasticizer materials, respectively. The characterizations of the sensor film comprise usage of Fourier transform infrared (FTIR), scanning electron microscope (SEM); in addition to determining the stoichiometric ratio between the components of the sensor using elemental analysis (CHN microanalysis). The analytical evaluation of the sensor film based on selectivity, sensitivity, and Nernstian behavior (55.8±1.1 mV/decade) are shown. The relative high selectivity of sensor towards NA as a target in the presence of several common interferents are exhibited. The ISE possesses a satisfactory sensitivity by recording a detection limit of 0.005 μM. The sensor also experiences a Nernstian behavior during all measurements. The dynamic linear range lies between 0.01 and 100 μM at 25 °C with R2=0.9998. The shelf life is 17 s and longevity lasts four months.