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How Do I Choose the Right Inlet Liner?

A Technical Tip by: Kristen Parnell, GC Brand Manager
and Kory Kelly, GC Product Manager

FocusLiner? Glass Wool? Direct Connect?

With so many features and designs, how do you choose the right inlet liner for your analysis? Each style of inlet liner offers a different range of benefits – to get the best performance, the key is to choose a liner that is well-suited for your injection type, sample, and budget. Below is a basic overview of liner styles:

Straight
GC accessories volatiles straight liner
Example: AG2-0A00


Function: Low surface area for less activity
Recommended for: Volatiles

Advantages

  • Simple to use
  • Least expensive
  • Low activity

Disadvantages

  • Possible inlet discrimination
  • More frequent gold seal maintenance from exposure to sample contamination
  • Possible inconsistency if sample injection bypasses split ratio

Glass Wool
GC accessories glass wool liners

Example: AG0-4656


In the middle

Function: Traps non-volatiles; mixes sample; vaporizes sample above the column
Recomended for: Dirty samples, volatiles, high initial oven temperatures

Advantages

  • Reduces gold seal/column contamination and maintenance
  • More reproducible results
  • Can help focus analytes
  • Extends column life

Disadvantages

  • Higher surface area that can become active
  • Glass wool can become dislodged

Glass Wool
GC accessories non volatile liners

Example: AG2-0A11-05


At the bottom

Function: Traps non-volatiles; mixes sample; vaporizes sample above the column
Recomended for: Dirty samples

Advantages

  • Reduces gold seal/column contamination and maintenance
  • More reproducible results
  • Can provide higher responses than wool in middle

Disadvantages

  • Higher surface area that can become active
  • Glass wool can become dislodged

Glass Wool
GC accessories liners for dirty samples

Example: AG2-0A03-05


At the top / FocusLiner

Function: Keeps glass wool in place; wipes syringe needle clean
Recomended for: Pressure pulsed injections, dirty samples, volatiles,
high initial oven temperatures

Advantages

  • Reduces gold seal/column contamination and maintenance
  • More reproducible results
  • Can help focus analytes
  • Extends column life

Disadvantages

  • Higher surface area that can become active

Taper / Gooseneck      
GC accessories water injection in GC

Example: AG0-8173


At the top

Function: Limits the expansion of the solvent to the inlet
Recomended for: Water injections

Advantages

  • Allows for larger injection volumes
  • Decrease backflash

Disadvantages

  • Higher risk of needle breakage
  • Increased cost
  • Cannot self-pack with glass wool

Taper / Gooseneck
GC accessories liners for pesticides

Example: AG2-0A10-05


At the bottom

Function: Directs flow onto column; low surface area
Recomended for:Pesticides (without wool), semi-volatiles (with wool)

Advantages

  • Reduces gold seal/column contamination and maintenance
  • Improved sensitivity
  • Lower activity

Disadvantages

  • Increased cost

Direct Connect Liner
GC accessories splitless injection


Examples: AG2-0A50-05

Function: Connects directly to column to aid transfer of analytes
Recomended for: Trace analysis, splitless injections, separation from
solvent peak (with top hole), aqueous samples (with bottom hole)

Advantages

  • Better sensitivity for splitless injections
  • Decreases inlet discrimination

Disadvantages

  • Only used for splitless injections
  • Increased cost
  • One-time use

Internal Diameter (ID)
GC accessories liners better peak shape

Example: AG0-4654


Small

Function: Small internal volume and surface area; restricts sample diffusion
Recomended for: Headspace , purge and trap, or gas injections ; active
samples with low expansion solvents

Advantages

  • Better peak shape of gaseous samples
  • Less activity for small injections of active compounds

Disadvantages

  • Very small internal volume is easy to overload with normal injection volumes

Outer Diameter (OD) /
Splitless Liner
GC accessories liners splitless injection

Example: AG0-8499


Large OD / Splitless

Function: Fits tightly inside the inlet; limits sample contact with inlet components
Recomended for: Splitless injections of active compounds

Advantages

  • Better sensitivity for long splitless hold times

Disadvantages

  • Not very amenable for changing to large split ratios

Cup Liner
GC accessories liners reproducible results

Example: AG0-4648


Function: Cup traps non-volatiles but has lower surface area than wool; vaporizes
sample above the column
Recomended for: Multiple or large volume injections, active samples, dirty samples

Advantages

  • Good sample mixing
  • Reduces gold seal/column contamination and maintenance
  • More reproducible results
  • Improves results for active compounds
  • Provides receptacle for multiple injections

Disadvantages

  • Increased cost
  • Higher surface area than straight liner can result in increased activity for very active compounds

A wide variety of liners is available. If you need additional assistance, we’re here to help!