JRC scientists have successfully developed and validated a low-cost method for accurate size measurements of silica nanoparticles with diameters between 50 nm and 200 nm based on a commercial centrifugal liquid sedimentation technique.
The method is particularly useful for routine laboratories and industry that need to screen samples for the presence of nanoparticles.
Nanoparticles are nowadays employed in a wide variety of consumer products such as food, cosmetics, clothing, textile, medicines, sports equipment, and electronic components.
Along with the widespread use and thus the increased exposure to nanoparticles, concerns arise about their potential adverse health effects. In safeguarding public health and the environment in the EU, legislation requires industry to provide reliable data on the presence of nanoparticles in products intended for the European market.
One of the most powerful techniques available for measuring the size of nanoparticles is electron microscopy. This technique allows to visualise the nanoparticles and to readily measure the particles’ external dimensions with a resolution of 1 nm.
However, an electron microscope is an expensive apparatus that can only be operated by highly trained personnel. As a result, electron microscopes are not often applied for routine measurements.
Instead, the cuvette centrifugal liquid sedimentation (CLS) technique allows simultaneous analysis of up to 12 samples with a minimum of operator intervention and thus human error.
The newly developed and validated method, which makes use of a commercial CLS instrument, has demonstrated its capability to measure the size of silica nanoparticles with diameters in the range of 50 nm to 200 nm with an expanded measurement uncertainty of < 10 %. In addition, it was shown that even particles as small as 20 nm could be detected.
While the CLS method is less powerful than electron microscopy, it has high potential for routine particle size measurements, typically required by industry and quality control laboratories.
J.M. Antúnez Domínguez, Y. Ramaye, M. Dabrio, V. Kestens, "Validation of a homogeneous incremental centrifugal liquid sedimentation method for size analysis of silica (nano)particles", Materials 13 (2020) 3806
- 3 december 2020