Selection Guide - GC ferrules

SilTite Metal Ferrules

SilTite Metal Ferrules

SilTite metal ferrules have been developed specifically for use with GCMS systems and have distinct advantages over graphite and composite ferrules for use with GCMS interfaces:

  • SilTite ferrules form a strong permanent airtight seal around the capillary column.
  • The metal SilTite ferrule and nut are made from the same material and therefore have the same thermal expansion coefficient. As the oven heats up and cools down, the nuts and ferrules expand and contract at the same rate, eliminating annoying leaks and the need to retighten the ferrule after installation.
  • The base of the SilTite ferrule is flat and forms a perfect seal with the MS interface, covering the whole transfer interface.
  • Specifically designed non-Swagelok SilTite nuts, characterized by two notches on the outer surface of the nut. The inner taper of the nut corresponds to the angle of the SilTite ferrule, ensuring an even closure of the ferrule around the whole column eliminating leaks.
  • SilTite nuts are reusable. Unlike graphite Vespel® ferrules that are nearly impossible to remove from the nuts after use, SilTite ferrules are easily removed from the specially designed nut while still attached to the capillary column.
  • SilTite metal ferrules have a temperature tolerance well above the limit of the injector, MS interface or GC oven.
  • SilTite nuts and ferrules are available for most major GC/MS instrument interfaces.
  • Removes contamination caused by Vespel or graphite ferrules.
  • Reduced air background gives a cleaner spectra with better library matches
15% Graphite / 85% Vespel® Ferrules

Graphite Vespel Ferrules

  • Mechanically robust
  • Hard material, long lifetime.
  • Temperature Limit 350° C
  • Must retighten after initial temperature cycles
  • Forms strong grip with column
  • Cannot be re-used with another capillary column
  • For GC-MS interface
  • Identify by dull dark grey lustre
100% Graphite Ferrules

Graphite Ferrules

  • Easy to use
  • Forms a stable seal
  • Soft material - can be squashed
  • Porous to oxygen (O2) (not for GC-MS)
  • Temperature limit 450°C
  • Forms ‘soft’ grip with column
  • Re-useable
  • Identify by shiny grey lustre