Influence of Anionic, Cationic and Nonionic Surfactants on Response of Ibuprofen PVC Sensors

One of the problems in pharmaceutical analysis is the influence of surfactants on the determination of active substances in pharmaceuticals using various methods, e.g., potentiometry. In the investigations were examined the effect of anionic: sodium dodecyl sulphate (SDS), cationic: tetrabutylammonium chloride (BTE), and nonionic (Tween-20, Tween-60, Tween-80, Brij 35) surfactants on the potentiometric properties of polymeric membrane ibuprofen electrodes. The performance characteristics of these electrodes, their selectivity and response time in the absence and in the presence of surfactants were studied. Both anionic and cationic surfactants interact with polymer membrane being divided into the aqueous phase and the membrane phase. The anionic surfactant SDS at a concentration of over 10^–5 M decreased the electrode potential and made the electrode lose its performance. The concentration of BTE greater than 10 –3M decreased the sensitivity of the ibuprofen electrode. The nonionic surfactant did not cause any changes in the calibration graph, response time or selectivity of ibuprofen electrodes. The proposed potentiometric electrodes are simple and cheap tool. They are characterized by favorable analytical parameters, good accuracy and they can be applied for ibuprofen determination in pharmaceuticals containing i.a. nonionic surfactants of type Tween.