Ion-selective electrodes for determination of fluoxetine in capsules and in biological fluids

Fluoxetine (FX) ion selective liquid membrane and coated wire graphite electrodes have been constructed from poly(vinyl chloride) containing FX-tetraphenylborate (FX-TPB) as the sensing element in the presence of DOP as the plasticizing solvent mediator. The two electrodes show nearly Nernestian response over the concentration range 2 × 10−5-1 × 10−2 mol/L of the drug with slopes of 58.5 and 55.5 mV/decade for the liquid membrane and the coated wire graphite electrodes, respectively. The electrodes exhibit good selectivity for the FX with respect to a large number of inorganic cations and organic substances of biological fluids. The method is precise as shown by the mean recoveries range of 100.50-101.04% and 99.69-100.17% with mean relative standard deviations 0.96-1.10% and 0.82-1.03% for liquid membrane and coated wire graphite electrodes, respectively. Fluoxetine is determined successfully in pure solutions and in capsules or in biological fluids using the standard additions and potentiometric titrations methods.