Methodologies for the Taylor dispersion analysis for mixtures, aggregates and the mitigation of buffer mismatch effects

Abstract

Taylor Dispersion Analysis (TDA) is a fast and simple method for determining hydrodynamic radii. For a mixture of solutes, current TDA methods lead to an average hydrodynamic radius for the different constituents of the mixture. In this paper, we first derive this average for the fitting method. Next, we present a method of deconvoluting a taylorgram from a mixture into its constituent taylorgrams so that the hydrodynamic radii and relative proportions of the individual components can be obtained. Using the differentials and integrals of the taylorgram, near-accurate initial estimates for the parameters of the constituent taylorgrams are obtained. These are used as seed parameters in least-squares fitting algorithms which find the optimum solutions for the constituent taylorgrams. Furthermore, the proximity of the seed parameters to the solutions is a measure of the confidence in the accuracy of the fits. The method is applied to two-, three- and four-component mixtures as well as aggregated samples with good agreement obtained between the results and the expected values. In addition, a fitting method which mitigates the effect of concentration mismatches between the eluent phase and the sample matrix phase is presented.