GC Injector Liner (Split/Splitless) — Sales and Instrument Support

Deactivated glass injector liner for a split/splitless GC inlet. The liner is where the injected liquid flashes to vapour, so it has to hold that vapour, mix it, and pass it to the column without adsorbing anything on the way.

Liner geometry is part of the method, not an accessory. Split work commonly uses a liner packed with a plug of glass wool or a taper to help vaporisation and trap non-volatile residue; splitless work uses a straight or single-taper liner with enough internal volume to contain the expanded solvent vapour. One microlitre of solvent can expand to several hundred microlitres, and on some solvents past a millilitre, at inlet temperature and pressure. When the liner is too small for that volume, the vapour backflashes out of the liner - giving poor repeatability, carryover and ghost peaks that look like contamination.

Two separate failure modes

• Dirty: non-volatile residue builds up, producing ghost peaks and drifting response. Replace the liner, septum and O-ring together.
• Active: the deactivation is lost with use, and active compounds - acids, bases, hydroxyl compounds - adsorb on the surface. This shows as peak tailing and low recovery for those compounds only, while everything else looks normal.