Cross-frontal mode: An alternative methodology for Taylor dispersion analysis of monomodal sample

Taylor dispersion analysis (TDA) is a technique dedicated to the determination of the molecular diffusion coefficient (D) of species, using band broadening of an analyte in a laminar flow. Two modes are com-monly used to perform TDA: pulse and frontal modes. In each case, a fitting of the signal is required. We propose here a third mode denoted as cross-frontal mode, combining two crossed sample fronts without modification of a classical CE device for the rapid and accurate determination of D of caffeine, reduced glutathione (GSH), insulin from bovine pancreas, bovine serum albumin (BSA) and citrate-capped gold nanoparticles (AuNP). Theoretical aspects and methodology are described, showing a good correlation between the so-called cross-frontal mode and usual frontal mode. Limitations of the techniques are also assessed, and are similar to regular modes while no fitting is required. This new methodology allows improving the sensitivity toward low concentrated sample compared to pulse mode, and an alternative mathematical treatment compared to regular TDA modes.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Taylor dispersion analysis (TDA) is a technique for determining the molecular diffusion coefficient of species by analyzing the band broadening of analytes in laminar flow. This study introduces a new method called cross-frontal mode, which combines two crossed sample fronts to accurately determine the diffusion coefficient of various substances. The cross-frontal mode shows good correlation with the usual frontal mode, and offers improved sensitivity and alternative mathematical treatment compared to regular TDA modes.