Nanoparticle Tracking Analysis
Nanoparticle Tracking Analysis (NTA) technology is one of the first commercially available technologies allowing high-resolution particle size distribution on a number-weighted basis and concentration analyses of submicron particles.
NTA technology employs the following steps:
1. A highly focused laser passes through a liquid dispersion in a specially designed cell. As the nanoparticles in the dispersion interact with the laser, they are observed as points of light moving under Brownian motion through a microscope.
2. The rate at which the particles move is a function of their diffusional rate, which is in turn a function of their size as given by the Stokes-Einstein equation. By tracking the motion of each particle over a specified amount of time, the diffusional rate can be measured and the particle size calculated. Since the cell is a known volume and the particles present are individually counted, an accurate particle concentration can be calculated simultaneously.
ASTM E2834-12 and ISO 19430:2016 describes this innovative technique and provides guidance for industry use.
Advantages
- Higher resolution than Dynamic Light Scattering
- True particle counter – yields number-weighted distribution
- Provides concentration results; number of particles per mL of fluid
Considerations
- Only analyzes samples prepared in an aqueous suspension
- Detection range about 30 nanometers to 1 micron
- Heterogenous material cannot be distinguished
Sample Requirements
Sample amount is not an easy question to answer, since it depends on the particle size and general nature of the material, as well as the technique that will be used. Ideal aqueous suspension sample amount is 20 mL and
1 gram for solid samples with instructions for re-suspension.
Although, less sample can be analyzed if need be. Questions on sample needs – please contact us to share specifics about your sample and options for suitable sample quantities.
Detection Range
PTL’s Nano Department can measure particulate from approximately 30 nanometers (nm) up to 1 micron (µm) with the Nanoparticle Tracking Analysis technique.
Data Reported
A comprehensive summary including the general graphical particle size distribution on number distribution will be provided, as well as the most commonly requested parameters (10th, 50th and 90th percentiles, etc.). Information on specific sizes can be reported on request. Concentration of particle per mL is also reported.
Sample Reports
Instrumentation
Particle Technology Labs uses the Malvern NanoSight NS300 for Nanoparticle Tracking Analysis.
