Optimizing GC Performance

In this edition of the Chromatography Series, we are taking a closer look at one of the most underrated — yet absolutely critical — parts of any gas chromatography system: the inlet liner. 

The liner is the first place your sample meets the GC system. A poor choice here can ruin even the most carefully prepared method — leading to tailing peaks, loss of active compounds, carry-over, column contamination, or reduced sensitivity. Get it right, and you unlock sharper peaks, better reproducibility, and longer column lifetime.

Why Liner Selection Really Matters

• Geometry & Volume 
  Split liners with narrow bores concentrate the sample for fast transfer → ideal for high-concentration samples or when you want to minimize band broadening. 
  Splitless / focus liners with larger internal volumes and a cup or wool packing give volatile analytes time to condense and re-vaporize → better for trace-level analysis. 
• Deactivation Quality 
  Active sites on an under-deactivated liner can irreversibly adsorb or degrade sensitive analytes (pesticides, drugs, free acids, bases, phenols, etc.). Premium deactivated liners (e.g., silanized or proprietary deactivation) reduce tailing and improve recovery — especially important for polar and thermolabile compounds. 
• Packing / Wool 
  Quartz wool or glass wool packing helps wipe the syringe needle, traps non-volatile matrix material, and improves sample vaporization uniformity. But the wrong wool type or amount can cause adsorption or catalytic decomposition. 
• Material & Surface Treatment 
  Most modern liners are borosilicate glass, but some applications benefit from quartz or metal liners. Surface treatments (e.g., base-deactivated, acid-deactivated, or universal deactivation) are matched to analyte chemistry. 

Common Liner Types & Typical Applications 

• Split / Splitless Straight-Through → General-purpose, robust for routine work 
• Single Taper / FocusLiner® → Excellent for splitless injections; focuses analytes at the head of the column 
• Double Taper → Minimizes contact with metal parts; great for active compounds 
• PTV (Programmable Temperature Vaporizer) Liners → Temperature-programmed injection reduces discrimination and thermal degradation 
• Direct / On-Column Style → For very dirty or thermally labile samples 

Teknokroma’s GC Liner Portfolio at Nordic BioLabs

Nordic Biolabs offers Teknokroma’s comprehensive range of inlet liners, precision-manufactured and rigorously deactivated to deliver consistent, high-performance results. Compatible with: 

• Agilent 7890 / 6890 / Intuvo 
• PerkinElmer Clarus 
• Varian / Bruker GC systems 
• Shimadzu, Thermo, and many others (ask us for compatibility) 

Popular choices include: 

• Low-Volume Focus Liners with quartz wool for trace pesticide and environmental analysis 
• High-Capacity Split Liners for complex food, flavor & fragrance, or petrochemical matrices 
• Premium Deactivated Liners (S deactivation series) for drugs of abuse, steroids, and other active analytes 
• PTV Liners designed for cold on-column or large-volume injection techniques 

All Teknokroma liners undergo strict quality control — including inertness testing — to ensure minimal activity and maximum analyte recovery. 

Practical Tip for Your Lab

A quick way to diagnose liner problems: 

• Tailing peaks on polar compounds? → Likely active sites → try a fresh, high-quality deactivated liner 
• Loss of early-eluting volatiles? → Wrong geometry or poor deactivation → switch to a focus liner 
• Matrix buildup or ghost peaks? → Replace liner more frequently and consider wool-packed versions 

Small investment in the right liner = big gains in data quality and instrument uptime.

Ready to upgrade your inlet? Contact us at Nordic Biolabs — we will help you select (and supply) the optimal Teknokroma liner for your Agilent, PerkinElmer, Varian or other GC system.

Iben Kofoed Piper
Sales & Portfolio Manager, Denmark
iben.kofoedpiper@nordicbiolabs.dk
+45 9384 5256

Browse through our assortment of GC liners here.