Investigating the Effect of Column Geometry on Separation Efficiency using 3D Printed Liquid Chromatographic Columns Containing Polymer Monolithic Phases

Abstract

Effect of column geometry on the liquid chromatographic separations using 3D printed liquid chromatographic columns with in-column polymerized monoliths has been studied. Three different liquid chromatographic columns were designed and 3D printed in titanium as 2D serpentine, 3D spiral, and 3D serpentine columns, of equal length and i.d. Successful in-column thermal polymerization of mechanically stable poly(BuMA-co-EDMA) monoliths was achieved within each design without any significant structural differences between phases. Van Deemter plots indicated higher efficiencies for the 3D serpentine chromatographic columns with higher aspect ratio turns at higher linear velocities and smaller analysis times as compared to their counterpart columns with lower aspect ratio turns. Computational fluid dynamic simulations of a basic monolithic structure indicated 44%, 90%, 100%, and 118% higher flow through narrow channels in the curved monolithic configuration as compared to the straight monolithic configuration at linear velocities of 1, 2.5, 5, and 10 mm s, respectively. Isocratic RPLC separations with the 3D serpentine column resulted in an average 23% and 245% (8 solutes) increase in the number of theoretical plates as compared to the 3D spiral and 2D serpentine columns, respectively. Gradient RPLC separations with the 3D serpentine column resulted in an average 15% and 82% (8 solutes) increase in the peak capacity as compared to the 3D spiral and 2D serpentine columns, respectively. Use of the 3D serpentine column at a higher flow rate, as compared to the 3D spiral column, provided a 58% reduction in the analysis time and 74% increase in the peak capacity for the isocratic separations of the small molecules and the gradient separations of proteins, respectively.

Direct 3D printing of monolithic ion exchange adsorbers

“…The third approach aims at custom design and 3D print the column casing only, which is later packed with commercial adsorber particles [19] or monolithic structures [20]. This approach is particularly original and can lead to column geometries with improved performance [21], but cannot be considered 3D printing of chromatography stationary phases.…”

3D printing for chemical, pharmaceutical and biological applications

“…9 Further developments in this area have produced the first 3D printed microfluidic pump that is null in its electrical requirements. 14 The same group has also utilised FDM to print a single piece photometric detector body with slit, which when integrated with a commercial light-emitting diode (LED) and photodiode either side of capillary tubing, allowed quantitative photometric detection. 15 Finally, inkjet printing has been applied to the production of a chemiluminescence detector used in the detection of hydrogen peroxide in urinary and coffee extracts, 16 as well as the manufacture of polymer thin layer chromatography (TLC) platforms, demonstrated by the planar separation of both visible dyes and fluorescently tagged proteins.…”

Recent strategies to enhance the performance of polymer monoliths for analytical separations

“…Typically, polymer monoliths are synthesized in capillary column format for applications such as stationary phases for chromatographic separation. Alternative formats have been recently described synthesizing polymer monoliths phases within photonic crystal fibre capillaries , or in 3D printed geometrically complex columns .…”

“…The effect of column geometry on the chromatographic separation using polymer monoliths as stationary phases was explored by fabricating different column holder designs using SLM 3D printing . Different column geometries were fabricated to hold polymer monoliths including a 2D serpentine column (Figure A), a 3D spiral column (Figure B), and a 3D serpentine column (Figure C).…”