Clenbuterol Determination in Pharmaceutical Formulation by Potentiometric Membrane Sensor

Clenbuterol is a selective beta(2)-adrenoceptor agonist which has been known as a thermogenic drug. This work introduces design and construction of a PVC membrane sensor for fast and simple determination of Clenbuterol in pharmaceutical formulation. The designed electrochemical sensor responds based on ion-pair exchange mechanism. Clenbuterol-Tetraphenyl borate was synthesized and used as sensing element of the membrane. After a series of experiments, the best electrode performance was selected with a membrane composition of 30% PVC, 60% DBP, 2% room temperature ionic liquid and 8% ion-pair. Room temperature ionic liquid was used as an additive and improves the sensitivity of the sensor. This electrode has a rather fast (similar to 34 s), stable and Nernstian response (57.5 +/- 0.4 mV/decade) in a wide concentration range of 5.3x10(-6) to 1x10(-2) mol L-1, and applicable pH range of 3-6. Validation of the method shows suitability of the sensors for analysis of Clenbuterol in pharmaceutical tablets. The sensor shows good repeatability with RSD of 4.7%.