Microtrac’s NANOTRAC Flex is a highly flexible nanoparticle size analyzer based on Dynamic Light Scattering (DLS) which provides information on particle size, concentration, and molecular weight. It allows faster measurements with reliable technology, higher precision, and better accuracy. All of this combined into a compact DLS analyzer with a revolutionary fixed optical probe.
With the unique and flexible probe design and the use of the Laser Amplified Detection method in the NANOTRAC FLEX, the user is able to choose an appropriate vessel as a measurement cell to satisfy the needs of any application. This design also allows measurements of samples over a wide concentration range, monomodal or multimodal samples, all without prior knowledge of the particle size distribution. This is made possible through the use of the Frequency Power Spectrum (FPS) method instead of classical Photon Correlation Spectroscopy (PCS).
| Method | Backscattered laser-amplified scattering reference method |
| Calculation model | FFT power spectrum |
| Measurement angle | 180? |
| Measuring range | 0.3 nm - 10 ?m |
| Sample cell | External probe (in situ) |
| Zeta potential analysis | no |
| Molecular weight measurement | yes |
| Molecular weight range | <300 Da -> 20 x 10^6 Da |
| Temperature range | +4?C - +90?C |
| Temperature accuracy | ? 0.1?C |
| At line / in line measurement | yes |
| Reproducibility (size) | =< 1% |
| Sample volume size measurement | one drop – ∞ |
| Concentration measurement | yes |
| Sample concentration | up to 40 % (sample dependent) |
| Carrier fluids | Water, polar and unpolar organic solvents, acid and base |
| Laser | 780 nm, 3 mW |
| Humidity | 90 % non-condensing |
| Dimensions (W x H x D) | 180 x 300 x 260 mm |
The optical bench of the nanoparticle size analyzer NANOTRAC FLEX is a probe containing an optical fiber coupled with a Y splitter. Laser light is focused on a volume of sample at the interface of the probe window and the dispersion. The high reflectivity sapphire window reflects a portion of the laser beam back to a photodiode detector. The laser light also penetrates the dispersion and the particle’s scattered light reflects at 180 degrees back to the same detector.
The scattered light from the sample has a low optical signal relative to the reflected laser beam. The reflected laser beam mixes with the scattered light from the sample, adding the high amplitude of the laser beam to the low amplitude of the raw scatter signal. This Laser Amplified Detection method provides up to 106 of times the signal to noise ratio of other DLS methods like Photon Correlation Spectroscopy (PCS) and NanoTracking (NT).
A Fast Fourier Transform (FFT) of the Laser Amplified Detection signal results in a linear frequency power spectrum which is then transformed into logarithmic space and deconvoluted to give the resulting particle size distribution. Combined with Laser Amplified Detection, this frequency power spectrum calculation provides robust calculation of all types of particle size distributions – narrow, broad, mono- or multi-modal – with no need for a priori information for algorithm fitting as it is for PCS.
Microtrac's Laser Amplified Detection method is unaffected by signal aberrations due to contaminants in the sample. Classical PCS instruments need to either filter the sample or create complicated measurement methods to eliminate these signal aberrations.
