Novel End-Capping Method With Silyl-Reagent Including Ethylene Chain

This poster introduces the Chromanik ArmorShell C18 Column and how it compares to other C18 Hybrid HPLC Columns.

  • Trimethylsilyl reagents (TMS) have been commonly used to cap silica-based reversed-phase LC packing. However, difunctional silyl reagents like hexamethyl dichloro trisiloxane have been introduced to reduce residual silanol groups on the silica gel surface, resulting in improved peak shape for strongly basic compounds. 
  • In this study, a new denser end-capping reagent called 1,2-bis(dimethylchlorosilyl)ethane was evaluated along with a high-temperature reaction to convert silanol groups into siloxane bonds. 
  • Comparison of ArmorShell C18 core-shell C18 phase with other C18 phases
  •  ArmorShell C18 shows similar stability to hybrid-type core-shell C18 columns under basic pH conditions
  • ArmorShell C18 exhibits higher stability than hybrid-type core-shell C18 columns under acidic pH conditions
  • The result is not attributed to the ethylene chain effect previously mentioned, but rather to an increase in efficiency or density of end-capping.
  • ArmorShell C18 demonstrates comparable inertness towards basic and metal chelating compounds
  • ArmorShell C18  shows a symmetrical peak shape with formic acid, unlike hybrid-type core-shell C18 columns with tailing peaks.