A comparative study of solid and liquid inner contact paroxetine hydrochloride ion-selective electrode membranes

A comparative study was made between two designs of paroxetine-selective electrodes: a polyvinyl chloride membrane (liquid inner contact) called electrodes PME1 and PME2 and a solid contact called electrodes CWE1 and CWE2 based on paroxetine-phosphotungstate and paroxetine-phosphomolybdate as ion exchangers. The four electrodes, PME1, PME2, CWE1 and CWE2, show linearity over the concentration range from 1 x 10(-5) to 1 x 10(-2) M, with slopes of 56.7, 54.4, 59.8 and 55.3 mV/decade, meanwhile the limits of detection were 2.5 x 10(-6), 4 x 10(-6), 5.6 x 10(-6) and 6.2 x 10(-6) M, respectively. PME1 and PME2 showed better limit of detection than electrodes CWE1 and CWE2. The present electrodes show clear discrimination of Prx.HCl from several inorganic, and organic species. The sensors were applied efficiently for determination of Prx.HCl in its pharmaceutical preparations using standard addition and the calibration curve methods.