Determination of Ondansetron Hydrochloride by a Liquid Membrane Potentiometric Sensor Based on Room Temperature Ionic Liquids

A new potentiometric sensor is introduced for simple and fast determination of Ondansetron hydrochloride in its formulations. Liquid membrane electrode in connection with Ag-Ag/Cl reference electrode was set-up and used for the potentiometric measurements. The membrane of the indicator electrode composed of a suitable ion-pair complex, dibutyl phthalate as the solvent mediator, PVC as a polymeric matrix and a room temperature ionic liquid (RTIL). RTIL helps the membrane to plasticize the media better and extract the drug ions from the aqueous solution to the organic phase of the membrane effectively. Different room temperature ionic liquids were tested. Using room temperature ionic liquids also decrease the Ohmic resistance of the membrane. The proposed sensor can applied in the concentration range of 5.0 x 10(-6)-1.0 x 10(-2) mol L-1 of Ondansetron with a detection limit of 4.5 x 10(-6) mol L-1. The potentiometric measurement can be done in pH range of 3.5 to 5.5. The proposed electrode displayed fast response time about 18 s and can be used for a period of seven weeks without any considerable change in its performance.