Two sets of polystyrene nanoparticles (PSNPs) with comparable core sizes but different carboxyl group densities were made and separated using asymmetric flow field flow fractionation (AF4), capillary electrophoresis (CE), and the off-line hyphenation of both methods. Our results revealed the significant potential of two-dimensional off-line AF4-CE hyphenation to improve the separation and demonstrated for the first time, the applicability of CE to determine the functional group density of nanoparticles (NPs). Compared to the result acquired with conductometric titration, the result obtained with synthesized 100 nm sized PSNPs revealed only a slight deviation of 1.7%. Commercial 100 nm sized PSNPs yielded a deviation of 4.6 %. For 60 nm sized PSNPs, a larger deviation of 10.6 % between both methods was observed, which is attributed to the lower separation resolution.

使用非对称流场流动分级分离（AF4），毛细管电泳（CE）和两种方法的离线联用，制备并分离了两组具有可比的核心尺寸但羧基密度不同的聚苯乙烯纳米粒子（PSNP）。我们的结果揭示了二维离线AF4-CE断字技术在改善分离方面的巨大潜力，并首次证明了CE在确定纳米颗粒（NPs）官能团密度方面的适用性。与通过电导滴定获得的结果相比，使用合成的100 nm大小的PSNP获得的结果仅显示出1.7％的微小偏差。商业100 nm大小的PSNP产生4.6％的偏差。对于60 nm大小的PSNP，两种方法之间观察到较大的10.6％的偏差，