The Comparison of Different Types of Instruments on Nanoparticle Size Measurements through Interlaboratory Comparisons

Abstract

There are several techniques for measuring and characterizing the nanoparticle sizes. However, these measurement results for same nanoparticles may deviate from each other at an amount that is considered significant. To establish the effectiveness and comparability of measurement methods on nanoparticles, the Center for Measurement Standards of Industrial Technology Research Institute (CMS/ITRI) conducted three inter laboratory comparisons on nano particle size measurements in 2005, 2006 and 2012. In 2005, an APEC-led preliminary inter laboratory comparison on nanoparticle size characterization was carried out among 10 laboratories from 6 economies. In 2006, the interlaboratory comparison was carried out for the second time with a more focused objective of detailing instrument-specific measurement instructions for enhancing the comparability among different types of measurement methods. There were 16 laboratories from 10 economies participating in that comparison. In 2012, to harmonize the measurement techniques and capabilities on nanoparticle size, an APMP supplementary comparison was held among 14 national measurement laboratories. In this paper, statistical analysis was carried out to identify that the nanoparticle size measured from Dynamic Light Scattering (DLS) was generally larger than the sizes measured from other measurement techniques including Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microcopy(AFM), Differential Mobility Analyzer (DMA), and Small-Angle X-ray Scattering (SAXS).