{"id":51859,"date":"2014-10-08T14:30:00","date_gmt":"2014-10-08T14:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/which-gc-injection-port-liner-to-use-for-gas-samples\/"},"modified":"2026-09-23T20:57:21","modified_gmt":"2026-09-23T20:57:21","slug":"which-gc-injection-port-liner-to-use-for-gas-samples","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/ja\/blogs\/gnbl4868\/which-gc-injection-port-liner-to-use-for-gas-samples","title":{"rendered":"Which GC injection port liner to use for gas samples"},"content":{"rendered":"\n

The answer seems fairly straightforward: Use a narrow internal diameter (ID) liner to keep peak shapes sharp by preventing band broadening; but this isn\u2019t always the correct answer. There has to be enough internal volume in the liner to contain all of the sample.  Let me explain.<\/p>\n\n\n\n

Let\u2019s first look at liners when using purge & trap (P&T)<\/strong>. All instrumentation that I am familiar with uses a transfer line from the P&T unit to the GC injection port.  In this case, you do want to use a narrow ID liner to minimize dead volume and prevent band broadening, especially for the compounds which will not condense and refocus within the capillary column.<\/p>\n\n\n\n

Now let\u2019s look at liners when using headspace (HS)<\/strong>. Headspace units can transfer the sample to the injection port two ways:<\/p>\n\n\n\n

(1) Using a Gas-Tight syringe to fill a sample loop (which is coupled to a transfer line).<\/p>\n\n\n\n

(2) Using a Gas-Tight syringe and injecting directly into an injection port liner.<\/p>\n\n\n\n

If the headspace unit uses a transfer line<\/strong>, then a small ID<\/strong> liner should be used. However, if a Gas-Tight syringe<\/strong> is used to inject the gas sample directly into an injection port liner, then a large ID<\/strong> liner is commonly used. <\/p>\n\n\n\n

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 (Splitless<\/strong> injections)<\/p>\n\n\n\n

The liner below is a Restek Premium 4.0mm ID Single Taper Inlet Liner (23302), which is typically the best choice for gas injections of approximately > 250\u00b5L to 1mL.<\/p>\n\n\n

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 The liner below is a Restek Premium 2.0mm ID Single Taper Inlet Liner (23315), which is typically the best choice for gas injections less than approximately 250\u00b5L.<\/p>\n\n\n

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 (Split<\/strong> injections)<\/p>\n\n\n\n

If you are injecting gases into a liner using a Gas-Tight syringe and splitting your sample, choose an open-bottom liner (with no gooseneck or other restriction at the bottom), like 23301 (photo below). Restek Premium 4.0 mm ID Straight Inlet Liner<\/p>\n\n\n

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 If you are not using a syringe for sample introduction but instead the sample is from a purge & trap unit, headspace unit which uses a transfer line, or gas sampling valve, then the liner I usually recommend is 23333 (photo below).  Restek Premium 1.0mm ID Straight Inlet Liner<\/p>\n\n\n

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 Please note<\/strong><\/em> that these are representative liners for an Agilent GC with a split\/splitless injection port; the catalog number of the liner you would select depends upon your specific instrument and injection port<\/em>.  In addition<\/strong><\/em>, make sure the injection port liner internal diameter (ID) is large enough for a transfer line to fit into the liner (if applicable).  For example, I have heard that some transfer lines have an outside diameter (OD) that is larger than 1mm OD; in this case, you would need to use a liner with a 2mm ID or larger opening, and not the 1mm ID liner shown above.  As an example, I recently found out that the Agilent 7697 Headspace Sampler requires a 2mmID liner like Restek 23313.<\/p>\n\n\n

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\"decorative\"<\/figure>\n<\/div>\n\n\n
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 In summary, liner selection for gas samples will depend on your particular instrumentation and how the sample is introduced into the injection port liner. If your instrument uses a transfer line, then a small ID liner will likely provide you the best chromatography.  If a Gas-Tight syringe is used to inject the gas sample, a larger internal diameter liner will usually provide you the best results.<\/p>\n\n\n\n

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Restek’s Topaz GC Inlet Liners<\/h3>\n\n\n\n

Restek\u2019s Topaz GC inlet liners feature revolutionary technology and inertness to deliver the next level of True Blue Performance:<\/p>\n\n\n\n

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  • Deactivation<\/strong>\u2014unbelievably low breakdown for accurate and precise low-level GC analyses.<\/li>\n\n\n\n
  • Reproducibility<\/strong>\u2014unbeatable manufacturing controls and QC testing for superior reliability across compound classes.<\/li>\n\n\n\n
  • Productivity<\/strong>\u2014unparalleled cleanliness for maximized GC uptime and lab throughput.<\/li>\n<\/ul>\n\n\n