Victoria A Coleman*, Åsa K. Jamting, Jan Herrmann


Nanometrology Section,
36 Bradfield Road,
National Measurement Institute
West Lindfield, NSW, Australia


As bio-nano research advances from the laboratory towards consumer products, and with the emergence of regulations in various economic regions around the use of nanomaterials in such products, a suite of metrological infrastructure has been developed for accurate determination of particle size. Despite this, equivalent developments relating to the measurement of number concentration of particles in liquid suspension has not advanced at the same pace. Given the reliance of both regulations and many toxicological studies on particle number concentration, for example for determination of dose, this gap needs to be rapidly addressed.

Here, we use size-monodisperse gold nanoparticles and specifically prepared bi-modal distributions of these particles to explore the measurement of particle concentration, and the accuracy of the y-axis in a range of measurement techniques. Measurements of the particle number concentration by single-particle methods such as particle tracking analysis (PTA) and resonant mass measurement (RMM) are compared with the expected concentration, converted from mass-concentration values determined by inductively coupled plasma mass spectrometry (ICP-MS). The number concentrations obtained using single-particle techniques are also compared to the expected number concentrations obtained by ensemble techniques, such as differential centrifugal sedimentation (DCS). The strengths and weakness of the different techniques in conjunction with the relative uncertainties in the measurement of particle number concentration are considered.


Biographic Details

Name: Dr Victoria Coleman

Title: a/g Section Manager, Nanometrology

Affiliation, Country: National Measurement Institute, Australia

Phone: +61 28467 3820 Fax: +61 28467 3752 E-mail:

Research interests: Nanometrology, Nanoparticle Characterisation, Concentration, Dose