Dynamic light scattering advantages and disadvantages

Light sources that donвЂ™t make use of lasers are sometimes used to enhance the primary laser source to reveal extra information about particle size and shape. Laser diffraction particle size analysers donвЂ™t just measure simple diffraction effects. This technique is highly repeatable and knowing that the results can be relied upon ensures compliance to any requirements of the regulatory authorities (ISO 13320:2009 and USP 429) Feedback can therefore quickly be provided and repeat analyses can also be made quickly. This technique is so rapid that results can be derived in one minute or less. As the sample passes through the laser beam, diffraction is measured for all particles.

This technique allows for the whole of the sample to be measured. If itвЂ™s possible to do so, itвЂ™s preferable to take measurements in a liquid suspension. This technique promotes a high level of reproducibility and facilitates the use of dispersing agents and surfactants to determine the primary particle size. ItвЂ™s possible to use a recirculating cell to measure liquid suspensions and emulsions. In combination with a suspension analysis, it can support the assessment of the amount of agglomerated material in a dry state. Although this may result in a poorer level of dispersion than if a liquid dispersing medium was used, dry powders can be directly measured using a dry powder dispersion accessory like the Malvern Aero S. Even dry powders, from cohesive to fragile materials, can be measured through the technique of laser diffraction. The pharmaceutical and agricultural industries are two of the many industries that have benefited greatly from such advances. ItвЂ™s even possible to measure the paint thatвЂ™s sprayed from a nozzle in a paint booth. Laser diffraction offers new possibilities for measuring materials. In measuring particle size, a reliable analytical instrument will allow the user to measure particles between approximately 0.01 to 3500 microns in size. However, validation of equipment is possible to prove that itвЂ™s performing to a standard that can be traced. In this method, itвЂ™s not necessary for an instrument to be calibrated against a standard. An absolute method grounded in fundamental scientific principles.The spherical modelling theory remains the only accepted and logical choice used in a commercial device intended to analyse a wide range of samples, regardless of the actual particle shape and size. We will also discuss the Mastersizer 3000, the worldвЂ™s most popular particle sizing instrument, as the best solution for particle size analysis and identify a best practice sampling method.

In this article, we will cover the advantages of laser diffraction, as well as the inevitable challenges it faces. Sampling errors can vary the results in any particle sizing research - particularly when measuring larger particles. However, laser diffraction is not without its challenges. Laser diffraction is a popular particle sizing technique because it offers a number of advantages.

Dynamic light scattering advantages and disadvantages