Citalopram is an antidepressant drug used to treat depression associated with mood disorders. This research introduces the design of an ion-pair based polyvinylchloride (PVC) membrane sensor for the citalopram determination based on theoretical investigations.
For the membrane preparation, citalopram-tetraphenyl borate ion-pair was employed as an electroactive material in the PVC membrane. In parallel, several plasticizers were studied, i.e. dibutyl phthalate (DBP), acetophenon (AP), nitrobenzene (NB) and nitrophenyloctyl ether (o-NPOE). After a series of experiments, the best electrode performance was accomplished with a membrane composition of 30% PVC, 66% DBP, and 4% ion-pair. This electrode illustrated a fast (~5 s), stable and Nernstian response (58.6 ±0.3 mV/decade) across a relatively wide citalopram concentration range 1×10-5 to 1×10-2 M and in the pH range of 3.0-5.5. Validation of the method showed suitability of the sensors for the quality control analysis of citalopram hydrobromide in pharmaceutical formulation and urine. The proposed method was simple, accurate and precise and can be used as a detector for HPLC.