Particle Size Analyzers

• Crystallization and Precipitation, Recrystallization, Polymorphism Chemistry, Protein Crystallization, Lactose Crystallization
• Particle Size Distribution
• Formulations and Product Development
• Flow Assurance in Oil & Gas Production

Since acquiring Lasentec in 2001, METTLER TOLEDO has continued to advance the development of FBRM and PVM particle size analyzers. With thousands of in situ particle size analyzers installed worldwide from the R&D laboratory to the manufacturing plant, our probe-based technologies are acknowledged as the gold standard for particle size distribution analysis.  Our technology, including crystallization equipment, measures and visualizes the rate and degrees of change in particle and droplet systems as they naturally exist in process.

What Does Particle Size Mean?
Every particle has a specific shape and different three-dimensional elongation. Particle size is an effective way to describe and characterize the dimensional properties (length, width, and height) of a particle. Although particles are usually of three-dimensional nature, a one-dimensional size function (for example, chord length, particle length or spherical equivalent diameter) is frequently used in practice.

Why is Particle Size Analysis Important?
Different particles can have very different physical properties and a certain particle size and shape will be optimal for a specific purpose.

• Catalyst – Maximum Surface Area
• Medicines – Highest Bio-Availability
• Industrial Processing – Good Flowability

Particle size analysis is important for process optimization and quality control to ensure and document optimal particle properties. The wrong particle size, in the worst case, can mean that a particle product will not be fit-for-purpose and a downstream process might experience an unplanned shutdown.

What is Particle Size Measured In?
Particle size is measured in a length dimension like nm, µm, or mm. Depending on the industry and particles, a different size range can be applicable.

How Do You Measure Particle Size?
Macroscopic particles can, for example, be measured with a ruler or caliper. Microscopic crystals usually need more sophisticated analytical devices due to the reduced particle size. Typical particle size measurement techniques are image analysis, laser back-scattering, laser diffraction or sieve fraction analysis.

What is the Average Particle Size?
For particle populations of many different particle sizes (small to large) it is possible to calculate the arithmetic mean, median or mode as an integral function over all particles. The average particle size provides one averaged number that characterizes a larger particle population.

How Does a Particle Size Analyzer Work?
A particle size analyzer operates according to a specific method of measurement (for example, image analysis, laser back-scattering, or laser diffraction) with individual and method specific boundary conditions. There are a variety of particle size analyzers available. All particle size analyzers provide different values for the same particle, depending on their specific method of measurement.

The selection of journal articles below utilize particle size analyzers to address measuring solubility and metastable zone, crystallization design, seeding crystallization processes, optimizing crystal shape, monitoring supersaturation, polymoprphic crystallization, phase separation (oiling out), managing impurities, crystallization scale-up, and continuous crystallization.

• Seed Recipe Design for Batch Cooling Crystallization with Application to L-Glutamic Acid, Zhang et al., Ind. Eng. Chem. Res. 2019, 58, 8, 3175–3187
• Effect of a polymer binder on the extraction and crystallization- based recovery of HMX from polymer-bonded explosives, Kim et al., Journal of Industrial and Engineering Chemistry, Volume 79, 25 November 2019, Pages 124-130
  
• Diastereomeric Salt Crystallization of Chiral Molecules via Sequential Coupled-Batch Operation, Simon et al., AIChE Journal, Volume 65, Issue 8
  
• On-line observation of the crystal growth in the case of the non- typical spherical crystallization methods of ambroxol hydrochloride, Gyulai et al., Powder Technology, Volume 336, August 2018, Pages 144-149
  
• Characterization of a Multistage Continuous MSMPR Crystallization Process assisted by Image Analysis of Elongated Crystals, Capellades et al., Cryst. Growth Des. 2018, 18, 11, 6455–6469
  
• Development and Scale-Up of a Crystallization Process To Improve an API’s Physiochemical and Bulk Powder Properties, Durak et al., Org. Process Res. Dev. 2018, 22, 3, 296–305
  
• A continuous multi-stage mixed-suspension mixed-product-removal crystallization system with fines dissolution, Acevedo et al., Chemical Engineering Research and Design, Volume 135, July 2018, Pages 112-120