Organic latex nanoparticles have recently been introduced as pseudostationary phases for electrokinetic chromatography (EKC), with a significant advantage being compatibility with mass spectrometric detection.  Additionally, the synthetic approach utilized to generate these nanoparticles is highly versatile, and this presents opportunities to tune and optimize their performance. 

In the present study, the performance and selectivity of novel acrylate-based latex nanoparticles, synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization, have been studied using EKC.  The performance of the materials is enhanced through the use of strongly acidic ionic functional groups, which extend the utility of the pseudo-stationary phases to low pH environments.  Nanoparticles with a range of hydrophobic core chemistries and diameters have also been synthesized and evaluated.  The behavior and performance of the new pseudo-stationary phases are characterized as a function of chemistry and structure.   The linear solvation energy relationship (LSER) model is applied to characterize the solvent properties and interactions between the nanoparticles and analytes.  The solvent characteristics of the nanoparticles were found to be similar to other acrylate based co-polymers, and are not significantly altered by changes in the ionic group chemistry.  The overall solvent properties of the nanoparticles imply that the hydrophobic core of the particles is highly accessible, while interactions with the ionic shell are weak or non-existent

These fundamental studies of nanoparticle performance and selectivity should lead to better applicability and informed design of new nanoparticle pseudo-stationary phases for EKC.