Potentiometric sensing of levamisole hydrochloride based on molecularly imprinted polymer

A potentiometric sensor based on a molecularly imprinted polymer was fabricated for recognition and determination of levamisole hydrochloride. Characteristics of the proposed sensor were evaluated by measuring the potential response to levamisole hydrochloride in the activity range from 2.5 μmol L−1 to 100 mmol L−1 with a near Nernstian response of 57.0 mV/decade and a limit of detection of 1.0 μmol L−1. The response time of the sensor was short (<15 s) and the membrane could be used for 4 months without any significant divergence in response. The proposed sensor was highly responsive to levamisole but not to the similar structures, i.e., thiabendazole, (2-methylthio)benzothiazole or (2-amino)benzothiazole. The potentiometric selectivity coefficients of the proposed sensor were evaluated and it exhibited good selectivity to levamisole with respect to the electrode based on a non-imprinted polymer or the plasticized PVC membrane electrode based on levamisole hydrochloride-tetraphenyl borate. The applicability of the sensor was tested in potentiometric titration of levamisole hydrochloride in pure drug and tablet pharmaceutical form.