Application of a new modified carbon paste electrode for low level potentiometric determination of cetirizine

Cetirizine hydrochloride (CT) with name, (±) - [2- [4- [(4-chlorophenyl)phenylmethyl] -1 piperazinyl] ethoxy]acetic acid, dihydrochloride is an antihistamine is used for relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, sneezing, hives and seasonal allergetic rhinitis [1,2]. Few methods have been used for quantitative determination of cetirizine including fluorimetry [3], high-performance liquid chromatography [4] and voltammetry [5]. Carbon paste is an ideal electrode substrates due to its chemical inertness, low cost, fast response time, ease of fabrication in different configuration and renewability. These attractive features of carbon paste electrodes have been reasons for the considerable attention at the production of carbon based electroanalytical sensors. Since no potentiometric carbon paste sensor has been reported for the determination of cetirizine, the introduction of a modified carbon paste electrode for easy, fast, selective and sensitive quantification of this drug in deffrent media is very important. This work describes the possibility of using a derivative cetirizine-phosphotungstat as ionophore in the preparation of cetirizine potentiometric carbon paste sensor. The constracted sensor show a linear response with Nernstian slope of 59.5 mV in the concentration range of 7.4×10-9-5.6×10-5 M with a low detection limit of 5.0×10-9. The sensor was fully optimized in terms of composition, usable pH range, life and response time. The sensor show excellent selectivity for CT respect to cations and biological species. Temperature dependence of the sensor potentical response was examined and the thermal coefficient of the sensor was calculated. The sensor was sucessfully used for the determination of cetirizine in real samples such as cetirizine tablet and blood serum samples