GC Columns

Shimadzu’s suite of GC columns is renowned for precision separation, thermal stability and low-bleed credentials, making them invaluable across many industries, including pharmaceutical and food safety applications, environmental testing and petrochemical manufacturing. While specific columns are tailored to different samples, resolution needs and applications, popular GC columns include:

• GC capillary columns
  One of the most common types of GC columns for GC analysis. These narrow, fused silica tubes also feature a thin internal liquid phase coating and are known for higher resolution and faster analysis than packed GC columns.
   

• Packed GC columns 
  Another common choice for GC analysis. These glass or stainless-steel tubes are filled with packing material and are suited to larger sample capacity thanks to their robust construction.
   

• PLOT GC columns
  These capillary columns are packed with solid particles, making them ideal for separating compounds that are gases across a wide range of operating temperatures. They offer unique selectivity for specific applications, such as light gases and volatile compounds.

Shimadzu supplies fused silica, PLOT, and metal GC columns, offering a wide variety of both general-purpose and application-specific formats to support routine and advanced analytical workflows. You can cross-reference Shimadzu’s suite of columns here.

FAQs

What are the main types of GC columns?

The main types of GC columns are capillary columns, packed columns and porous layer open tubular (PLOT) columns. Capillary columns are the most widely used GC columns due to their high efficiency and sensitivity. These GC columns are narrow, fused silica tubes with a thin internal coating, while packed columns are filled with packing material for larger sample capacity. PLOT columns are a type of capillary column that are suited to gas and volatile compound analyses.

How do I choose the right GC column for my application?

Choosing the right GC column for your application is largely determined by the properties of your sample and the objective of your analysis. It’s important that you also match the column polarity to your analyte polarity (i.e. non-polar columns for non-polar compounds and polar columns for polar compounds), consider the boiling-point range of your compounds, determine the required resolution versus analysis time, and check if your application requires specific columns for regulatory methods like EPA or USP. Shimadzu's GC column selection guide can help you identify the optimal column.

What is the difference between capillary and packed GC columns?

There are a couple of differences between capillary and packed GC columns, including size, applications and capabilities. GC capillary columns have an internal diameter of roughly 0.1-0.53mm, while packed GC columns are wider with an internal diameter of 2-4mm. GC capillary columns produce sharp peaks with excellent separation performance and high sensitivity, while the wider tubes of the packed GC columns are filled with solid support material, offering larger sample capacity and robustness but lower resolution. Capillary columns are preferred for complex mixtures requiring high resolution, while packed columns excel in gas analysis and methods requiring larger injection volumes.

What are PLOT GC columns used for?

PLOT GC columns are ideal for analyzing permanent gases (oxygen, nitrogen, carbon monoxide), light hydrocarbons and volatile organic compounds where traditional liquid stationary phases cannot retain these compounds effectively. This is because they have a porous absorbent layer bonded to the inner wall and are specifically designed for analyzing these light gases and highly volatile compounds.

How long do GC columns last?

GC column lifespan varies based on sample type, injection frequency, temperature exposure and the level of care and maintenance you undertake. Regular maintenance, appropriate temperature limits, and proper sample preparation extend column life significantly. For example, with proper care and use of guard columns, capillary columns typically last 6-18 months. It’s important to prioritize maintenance of columns and look out for signs that they need replacing, including peak tailing, loss of resolution, increased baseline bleed and retention time shifts.

What is column polarity and why does it matter?

Column polarity describes how the stationary phase interacts with analytes during separation. Column polarity is a vital consideration when choosing a GC column, as it will determine the column’s ability to separate and, therefore, analyze your sample mixture. Column polarity refers to the stationary phase's chemical properties and its interaction with analytes – it exists as an assigned value specific to GC columns. Non-polar columns (like 100% dimethyl polysiloxane) separate compounds primarily by boiling point, while polar columns have functional groups that interact with polar analytes for enhanced retention and selectivity. Choosing the right polarity is crucial, as it is the means by which you match your column polarity to your compound polarity for optimal separation and analysis.