A method and apparatus is provided for concentration determination of at least one component in an acid catalyst for hydrocarbon conversion containing an unknown concentration of an acid, an acid-soluble-oil (ASO), and water. An instrument configured for measuring a property of the acid catalyst, has responsivities to concentrations of one of the acid, ASO, and water, substantially independent of the concentrations of the others of the acid catalyst, ASO, and water. A temperature detector is configured to generate temperature data for the acid catalyst. A processor is configured to capture data generated by the temperature detector and the instrument, and to use the data in combination with a model to determine a temperature compensated concentration of the one of the acid, the ASO, and the water. Optionally, one or more other instruments configured for measuring other properties of the liquid mixture may also be used.