Particle Size Masterclass: How is particle size measured?

Log in to watch this webinar

Not registered yet? Create an account
00:00:00 Welcome
00:00:08 Speaker Introduction
00:01:18 How to measure particle size distribution
00:01:49 Abstract
00:02:04 Overview of Techniques
00:02:09 Number/visualization and volume/mass
00:03:56 The killer word…
00:05:23 How much sample do we need?
00:06:35 Before a particle size measurement?
00:08:57 Volume-Number
00:10:44 Size isn’t everything…
00:11:46 What do we ‘see’ with any technique?
00:12:41 Orientation of particle
00:13:17 The techniques that we’ll consider
00:13:22 Why so many techniques?
00:14:56 Sieving
00:15:37 Grizzly
00:16:46 All retained particles are considered the same (> 1”)
00:17:18 Sieves
00:17:48 Sieves
00:19:11 Sieves
00:19:28 Sieves
00:20:59 Sieving
00:21:39 Sedimentation
00:22:09 ‘Sample preparation’
00:23:41 Pre-treatment(s)
00:24:10 Stokes’ Law
00:25:31 Comparison with diffraction
00:26:04 Sedimentation
00:26:59 Microscopy/Image analysis
00:27:38 Microscopy/Image analysis
00:28:50 Microscopy/Image analysis
00:29:10 ~ 1.7 million particles measured
00:30:10 Electrical Sensing Zone or Coulter Counter
00:31:16 ESZ - Principle
00:31:35 Electrical Sensing Zone - (Coulter Counter)
00:32:20 Electrical Sensing Zone - (Coulter Counter)
00:33:04 Gas adsorption techniques (BET)
00:33:38 Gas adsorption techniques (BET)
00:33:51 Gas adsorption techniques (BET)
00:34:22 Small-angle X-ray scattering (SAXS)
00:36:20 Nanoparticle Tracking Analysis (NTA)
00:37:37 Resonant Mass Measurement – Archimedes
00:38:57 Light obscuration counters
00:40:10 Light scattering
00:41:13 Why laser diffraction?
00:43:32 Measurement principle
00:45:13 158 yards? Diameter of quarter?
00:45:46 J Raymond Hodkinson
00:46:09 Horace Edgar Rose (May 30th, 1913 – January 19th, 1999)
00:47:11 Halo around moon
00:47:37 Size of ice crystals
00:48:14 Variation of scattering angle with particle size
00:49:35 So what happens when the size gets small?
00:51:16 Just one photon…..
00:51:43 Particle sizing and Brownian motion
00:51:43 Dynamic Light Scattering
00:52:05 Correlation functions for different particle sizes
00:52:39 Calculating size distributions from the correlation functions
00:53:21 This is pretty important!
00:53:56 International Standards
00:54:58 Bonus slide!
00:55:10 Thank you
00:55:36 Appendix
00:55:41 Appendix
00:55:43 Appendix
00:56:00 Thank you for your attention

There is a gamut of particle size distribution measurement techniques each with established history and advantages. The killer word in particle size distribution ids the last one (distribution) and measurement of broad distributions is the bane of all sizing techniques. After a very short introduction to ‘how much sample should we measure to describe the distribution’, we’ll be running through the background of some of the more popular techniques (sieves, sedimentation, electrical-sensing zone) and will emphasize the popular light scattering techniques of laser diffraction and dynamic light scattering.  As anaside we’ll be mentioning Small-angle X-ray scattering (SAXS).  

We’ll look at counting techniques especially those in the nanotechnology (nanotracking analysis (NTA), resonant mass measurement (RMM)) and regulatory (obscuration counting) arena.  In line with the statement in USP <766> Optical Microscopy, “For irregularly shaped particles, characterization of particle size must also include information on particle shape’, we will look at the benefits of high speed image analysis where statistically valid numbers of particles can be counted and measured for both size and shape distribution.  We’ll point out 2 international (ISO & ASTM) standards that provide an overview to available methods.