US 11,899,035 B2
Methods for determining the density of polymer particles for quality control materials using split flow thin (SPLITT) cell fractionation principle and fractionation cell for carrying out the methods
Aravind Reghu, Scarborough, ME (US); Jui Ming Lin, Falmouth, ME (US); James Russell, North Yarmouth, ME (US); and Jeremy Hammond, Standish, ME (US)
Assigned to IDEXX Laboratories, Inc., Westbrook, ME (US)
Filed by IDEXX Laboratories, Inc., Westbrook, ME (US)
Filed on Sep. 21, 2021, as Appl. No. 17/480,607.
Claims priority of provisional application 63/081,029, filed on Sep. 21, 2020.
Prior Publication US 2022/0091004 A1, Mar. 24, 2022
Int. Cl. G01N 9/32 (2006.01)
CPC G01N 9/32 (2013.01) 9 Claims
OG exemplary drawing
 
1. A method for determining the density of particles, the method comprising:
passing a carrier fluid and particles suspended within the carrier fluid axially through a fractionation cell at a predetermined rate, wherein:
the carrier fluid has a predetermined density;
the fractionation cell has a housing including a first axial end and a second axial end opposite the first axial end and the fractionation cell defines:
an interior carrier fluid flow-through channel extending between the first axial end and the second axial end; and
at least an upper fluid outlet and a lower fluid outlet positioned below the upper fluid outlet in a vertical direction, the upper fluid outlet and the lower fluid outlet in fluid communication with the channel and positioned at the second axial end of the housing;
passing the carrier fluid and the particles through the upper fluid outlet and the lower fluid outlet;
measuring a first concentration of particles passing through the upper fluid outlet;
measuring a second concentration of particles passing through the lower fluid outlet; and
determining a density of the particles based at least in part on the first concentration and the second concentration of particles.