The extent to which a technique can be used to identify difference between sample characteristics is limited in part by its resolution capabilities. Although both Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle Tracking Analysis (NTA) measurements are based on the analysis of individual particles, major differences in their resolution capabilities have been revealed in systematic comparative studies (Vogel et al. 2021
, Caputo et al. 2021).
TRPS analysis of a quadrimodal sample, for example, reveals four clearly distinguishable peaks, representing the four subpopulations known to be present.
When using NTA to analyse quadrimodal samples of polystyrene particles, however, the peaks showing particle size distribution are wide and overlapping. The lower resolution makes it difficult to identify all subpopulations – and subsequently, obtain precise information about particle size distribution in the sample.