Do You Know What the Buffer Capacity of Your pH Buffer Is

Abstract

This paper develops the item of buffer capacity of pH buffers and targets chemists, biologists, physiologists or anyone who may be interested to become familiar with and develop a quantitative perception of factors controlling buffer capacity of aqueous solutions (which can be complex mixtures of acids and/or bases and/or ionic salts, as are commercial pH buffers in use in a variety of applications which require control of pH, or most biological fluids, e.g., blood). The fundamental idea of representing a pH buffer or a buffered biological fluid with a matrix constitutes the leitmotif of the suggested approach through which the boring complexity of a quantitative mathematical treatment of buffer capacity has been overcome. It is shown how the matrix representing a given pH buffer or biological fluid (from which a quantitative evaluation of pH and buffer capacity can be performed) can be built in a matter of minutes (regardless of their complexity) in a MS Excel sheet by employing an Excel library of custom functions which is made available as associated material to this paper. Furthermore, from the matrix representing the pH buffer or biological fluid a plot can be derived which is used as a graphical support for enlightening the chemical significance of the matrix and to connect the buffer capacity to the Acid-Base chemistry which takes place in the represented pH buffer or biological fluid.