Technological Comparision

SPES / SPES² (Single Particle Extinction and Scattering) patented optical technologies access to more information on single measured particles than the other methods. The capabilities of EOS analytical platform based on SPES / SPES² patented methods are of capital importance with mixes and heterogeneous systems and when particle behaviour must be investigated in complex-but-real target industrial, environmental, and biological heterogeneous liquids and aerosol.

SPES / SPES² data provides physical and statistical information, as particle size distribution and numerical concentration, as well as insight on the particle structure and stability. Applications ranges from the estimation of the number of aggregates per mL respect to the choice of the surfactant, e.g. for the improvement of the wetting of a powder or of the shelf life of a product, to the study of the behaviour of particles in target heterogeneous media to tailor the their formulation. Oversize analysis can be performed also in presence of impurities. Scraps and out-of-specifics can be monitored in intermediates and final formulation.

Among the several traditional methods currently adopted, optical ones have unique advantages, and therefore, have brought light scattering into the forefront of analytical methods in many scientific and industrial applications. Unfortunately, the number of parameters typically affecting the scattering properties of a given particle is such that the basic measure of the scattering power (or even the power removal from a light beam -extinction- from one particle) is far from being enough to recover something more than a rough estimate of its size. Things change appreciably when considering a collection of many scatterers, with the immediate drawback of introducing the need for mathematical inversion and ill-posed problems to interpret experimental real data. As a matter of fact, traditional optical methods, such as Dynamic Light Scattering (DLS), Static Light Scattering (SLS), and Light Obscuration (LO), require limiting a priori assumptions on the particles composition and structure and they assume that all particles are made by the same material and no interaction occurs between the particles and the fluid. Moreover, both DLS and SLS are based on complex retrieval algorithms that could introduce artefacts in the resultant particle size distribution.

SPES / SPES² provide a complete unique calibration-free optical fingerprint of the sample (see “how do SPES/SPES² work”). Thanks to its multiparametric approach and limiting a priori speculations. EOS proprietary algorithms and specific data analysis complete the instrument ability to discriminate and analyse samples even in situation when traditional methods fail.