Simultaneous estimation of the dissociation constant and concentration by a linear least-squares method with non-negative constraint

A potentiometric titration curve was expressed as a linear equation and solved by a linear least-squares method with a non-negative constraint to simultaneously estimate the pK value(s) and concentration(s) of acid(s). Artificial model titration curves based on a continuous pK distribution were also solved using the same method. Accurate estimates were made of the pK values and concentrations of acetic, formic, fumaric, and citric acids. Furthermore, the method was used to estimate the pK distributions and concentrations for continuous pK distribution systems.