Three dimensional characterisation of chromatography bead internal structure using X-ray computed tomography and focused ion beam microscopy

T. F. Johnson, J. J. Bailey, F. Iacoviello, J. H. Welsh, P. R. Levison, P. R. Shearing, D. G. Bracewell*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)
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Abstract

X-ray computed tomography (CT) and focused ion beam (FIB) microscopy were used to generate three dimensional representations of chromatography beads for quantitative analysis of important physical characteristics including tortuosity factor. Critical-point dried agarose, cellulose and ceramic beads were examined using both methods before digital reconstruction and geometry based analysis for comparison between techniques and materials examined. X-ray ‘nano’ CT attained a pixel size of 63 nm and 32 nm for respective large field of view and high resolution modes. FIB improved upon this to a 15 nm pixel size for the more rigid ceramic beads but required compromises for the softer agarose and cellulose materials, especially during physical sectioning that was not required for X-ray CT. Digital processing of raw slices was performed using software to produce 3D representations of bead geometry. Porosity, tortuosity factor, surface area to volume ratio and pore diameter were evaluated for each technique and material, with overall averaged simulated tortuosity factors of 1.36, 1.37 and 1.51 for agarose, cellulose and ceramic volumes respectively. Results were compared to existing literature values acquired using established imaging and non-imaging techniques to demonstrate the capability of tomographic approaches used here.

Original languageEnglish
Pages (from-to)79-88
Number of pages10
JournalJournal of Chromatography A
Volume1566
Early online date25 Jun 2018
DOIs
Publication statusPublished - 07 Sep 2018
Externally publishedYes

Bibliographical note

Funding Information:
This research was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/L01520X/1 . Paul Shearing acknowledges support from the Royal Academy of Engineering . We would like to thank Pall Biotech, Portsmouth, United Kingdom, for the supply and expertise concerning cellulose and ceramic chromatography materials, with particular gratitude towards Dave Hayden and Nigel Jackson. At the UCL Electrochemical Innovation Lab, Leon Brown and Bernhard Tjaden are thanked for constructive guidance and useful conversations. Focused ion beam was performed at the London Centre for Nanotechnology and Imperial College London Department of Materials, with thanks to Suguo Huo and Ecaterina Ware respectively.

Funding Information:
This research was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/L01520X/1. Paul Shearing acknowledges support from the Royal Academy of Engineering. We would like to thank Pall Biotech, Portsmouth, United Kingdom, for the supply and expertise concerning cellulose and ceramic chromatography materials, with particular gratitude towards Dave Hayden and Nigel Jackson. At the UCL Electrochemical Innovation Lab, Leon Brown and Bernhard Tjaden are thanked for constructive guidance and useful conversations. Focused ion beam was performed at the London Centre for Nanotechnology and Imperial College London Department of Materials, with thanks to Suguo Huo and Ecaterina Ware respectively.

Publisher Copyright:
© 2018 The Authors

Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.

Keywords

  • Bead scale
  • Focused ion beam microscopy
  • Key words
  • Structure
  • Tortuosity
  • X-ray computed tomography

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry

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