Determination of Cholic Acids by Ion Selective Liquid Membrane Electrode in Pharmaceutical Products

Abstract
An ion selective electrode based on a liquid membrane, constituted by a solution of tributylcetylphosphonium benzoate in nitrobenzene, is employed to determine cholic acids in pharmaceutical products by calibration curve and standard addition methods. The results are compared with those obtained with enzymatic and calorimetric methods. The proposed technique is simple, rapid and sufficently accurate.