This can make sample preparation iterative, challenging and time consuming and often requires the use of data filtering methods that leave an inaccurate estimate of the steady state size fraction and may provide no knowledge to the user of the presence of the transient fractions. The sixth power relationship between scattered intensity and particle radius is simultaneously a primary advantage whilst rendering the technique sensitive to unwanted size fractions from unclean lab-ware, dust and aggregated & dynamically aggregating sample, for example. Classical PCS instruments need to either filter the sample or create complicated measurement methods to eliminate these signal aberrations.Dynamic Light Scattering (DLS) is a ubiquitous and non-invasive measurement for the characterization of nano- and micro-scale particles in dispersion. Microtrac's Laser Amplified Detection method is unaffected by signal aberrations due to contaminants in the sample. 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. This Laser Amplified Detection method provides up to 10 6 of times the signal to noise ratio of other DLS methods like Photon Correlation Spectroscopy (PCS) and NanoTracking (NT).Ī 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. 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. The scattered light from the sample has a low optical signal relative to the reflected laser beam. The laser light also penetrates the dispersion and the particle’s scattered light reflects at 180 degrees back to the same detector. The high reflectivity sapphire window reflects a portion of the laser beam back to a photodiode detector. Laser light is focused on a volume of sample at the interface of the probe window and the dispersion. The optical bench of the nanoparticle size analyzer NANOTRAC FLEX is a probe containing an optical fiber coupled with a Y splitter. Additionally, the user can choose from a wide array of measurement cells to satisfy the needs of any application. The probe is also very easy and quick to clean between sample measurements of any kind. This probe design enables the measurement of samples over a wide concentration range, monomodal or multimodal samples, all without prior knowledge of the particle size distribution. This design ensures an accurate particle size distribution that is representative of the suspension outside the enclosure. An orifice ensures the constant exchange of the sample, while slowing down the stirring movement at the probe interface. This special cap for the NANOTRAC FLEX probe tip creates an enclosure around the probe, which shields the measurement surface from turbulent flow. To measure in stirring or moving liquids, the FlowGuard can be used. The dispersion motion will obscure the Brownian motion, and a Dynamic Light Scattering (DLS) measurement is normally not possible. This makes it possible to use the probe either at line or in line for monitoring the particles' growth during a reaction.ĭuring a reaction, the dispersion is either flowing or stirring. With the NANOTRAC FLEX, every vessel can be used as a measurement vessel, and there is no need for cuvettes of any kind. The probe also easily fits into a 1.5 ml Eppendorf Tube®. The unique design of the NANOTRAC FLEX probe allows to measure down to only one droplet, thus requiring only a minimum sample volume.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |