The particle size is one of the most important characteristics of particulate materials. The Particle Size Distribution (PSD) reflects the frequency of particles of a certain size in a sample and therefore indicates what sizes of particles in what counts or proportions are present in the particle system.

It is often expressed using percentile values. For example, the D10, D50, and D90 values mean that 10, 50 and 90% of particles in the sample are smaller than this size.

Depending on the substance group and size range there are different methods to determine the PSD.

Using Laser Diffraction and Dynamic Light Scattering we are able to perform measurements

• from 0.3 nm to 3500 µm particle size
• in wet dispersion (0.3 nm - 850 µm)
• in dry dispersion (100 nm - 3500 µm), freefall shaft to determine shear forces
• for solids, suspensions and aerosols
• determine the hydrodynamic diameter
• receive an approach to the MMAD (Mass Median Aerodynamic Diameter)

The analysis of the PSD is important in the context of:

• characterization of a substance for a REACH substance identity profile (sameness), e.g. for the definition of nanoforms
• granulometry for the REACH dossier of solid substances
• analytical determination of nanomaterials in genotoxicity or ecotoxicological studies
• water solubility

Sometimes complementary techniques such as SEM/TEM, XRD with Rietveld or BET are required to describe a substance in its entity.

We offer testing according to the following guidelines or based on an individual approach.

Dynamic Light Scattering:

OECD 110	Particle Size Distribution
ISO 22412	Particle Size Analysis — Dynamic light scattering (DLS)
ASTM D4001	Standard Test Method for Determination of Weight-Average Molecular Weight of Polymers by Light Scattering
ASTM E2490	Standard Guide for Measurement of Particle Size Distribution of Nanomaterials in Suspension by Photon Correlation Spectroscopy (PCS)
ASTM E2865	Standard Guide for Measurement of Electrophoretic Mobility and Zeta Potential of Nanosized Biological Materials
ASTM E3247	Standard Test Method for Measuring the Size of Nanoparticles in Aqueous Media Using Dynamic Light Scattering
ISO 13099-2	Colloidal systems — Methods for zeta-potential determination — Part 2: Optical methods
U.S. Pharmacopeia (USP) 1430	Analytical Methodologies Based on Scattering Phenomena—General
U.S. Pharmacopeia (USP) 729	Globule Size Distribution in Lipid Injectable Emulsions

Laser Diffraction:

OECD 110	Particle Size Distribution
ISO 13320:2020	Particle size analysis - Laser diffraction methods
ASTM B822 – 20	Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering
ASTM D4464 - 15(2020)	Standard Test Method for Particle Size Distribution of Catalytic Materials by Laser Light Scattering
ASTM E2316 - 14(2019)	Standard Test Method for Determination of Particles Resulting from the Attrition of Granular Pesticides
U.S. Pharmacopeia (USP) 429	Light Diffraction Measurements of Particle Size

 

Testing could be performed with GLP and could be used for regulatory purposes as well as R&D.

The above-mentioned techniques also enable us to determine the

• Zeta Potential of particles (surface charge) with a particle size of 3.8 nm - 100µm by ELS (Electrophoretic light scattering)
• refraction index (from 1.28 to 1.50) with high precision
• molecular mass SLS (Selective Laser Sintering) from 980 Da to 20 MDa
• dustiness

We offer this service for the following industries:

• Chemical industry: nanomaterials, adhesives, glue, colloids, detergents, inks, paints, coatings, emulsions, polymers
• Material science / nanotechnology
• Cosmetics, body care, pharmaceuticals
• Food industry

Contact us for more information!