Research Center for Process and Prevention of Water Pollution

Recently, Associate Professor Fengjun Yin successively published two academic papers in Electrochimica Acta and Industrial & Engineering Chemistry Research: “A Novel Electrochemical Method Determining pKa and Transport Parameters of Buffers Using Acid-Base Transport Limitation Response”, doi.org/10.1016/j.electacta.2023.143373，“Determining pKa and a New Total Diffusion Coefficient for Weak Acids via the Electrochemical Acid-base Transport Limitation Method”，doi.org/10.1021/acs.iecr.3c02856. A novel electrochemical method that simultaneously determines dissociation constants and diffusion coefficients of weak acids and bases was developed. Traditional methods are generally complex, application popularity is low, and many substances lack the diffusion coefficient data reserves. The relevant principles have been proposed for at least 30 years. The simultaneous determination of dissociation constants and diffusion coefficients has not never been reported yet. Our method is simple and fast to determine, does not require complex algorithms and large equipment, and is easy to develop as an automated device. The determined diffusion coefficients are in a new form, representing the average value of diffusion coefficients for a conjugate acid-base pair. Its value is independent on the dissociation degree and concentration of the acid-base substance, overcoming a major limitation of the traditional determinations.