Selective Determination of Diclofenac and Clomiphene with a Single Planar Solid-State Potentiometric Ion Selective Electrode

Abstract

A vital analytical procedure is that comprises less experimental variables, but maintains high efficiency, accuracy and selectivity for one or more than one target analyte. Commonly, ion selective electrodes are prepared and optimized for determination of one ion. Herein, we describe a double-use all-solid-state planar ion selective platform for determination of two incompatible drugs, namely, diclofenac (anion) and clomiphene (cation). The ion exchanger which is the key for thermodynamic ion exchange equilibrium was formed in-situ in the membrane phase utilizing drugs lipophilicity and drug-drug interaction. Drugs interaction and complex formation was elucidated by UV spectroscopy. Also, the morphology of the sensor was characterized using SEM. The effect of membrane plasticizer on the magnitude of the potentiometric response of the sensor was investigated. A sensor with tricresyl phosphate showed a Nernstian slope of 59.1 ± 0.5 and 57.8 ± 1.2 mV/decade for diclofenac and clomiphene, respectively. The electrode showed a high selectivity to diclofenac and clomiphene over common pharmaceutical excepients. The sensor was applied for determination of diclofenac and clomiphene in a variety of pharmaceutical dosage forms and drinking water with a high accuracy (±2%) and precision (%RSD ≤ 2.5).