Gas Chromatography (GC)

Thermo Scientific's gas chromatography (GC) solutions are designed to be customized so that they can fit any laboratory workflow. From Thermo Scientific Instant Connect injector and detector modules, to the performance-leading mass spectrometers, Thermo Scientific offers the largest portfolio of GC solutions that enable users to innovate as well as customize their GC application.

FAQ: Gas Chromatography (GC)

What is Gas Chromatography (GC) and when is it used?

Gas Chromatography (GC) is a technique used to separate and analyze compounds that can vaporize without decomposition. It is ideal for the analysis of gases, fuels, fragrances, pesticides, and many other volatile substances.

Which carrier gas should I use?

The most commonly used carrier gases are helium, nitrogen, and hydrogen. Hydrogen provides the best peak separation efficiency; however, due to its flammability, many users prefer switching to helium or nitrogen.

How do I choose the right GC column?

The selection depends primarily on the polarity of your analytes. Column series such as TraceGOLD offer a wide range of stationary phases designed to ensure minimal column bleed and excellent result reproducibility.

What causes changes in retention times in GC?

The most common causes are fluctuations in carrier gas flow or leaks at the septum. Systems such as the TRACE 1600 series feature modular injectors that simplify maintenance and help prevent these issues.

How often should the septum and liner be replaced?

These are consumable parts that directly affect peak quality. Regular replacement after a defined number of injections is recommended to prevent contamination and sample degradation.

Why is my chromatogram baseline unstable?

An unstable baseline typically indicates impure carrier gas or detector saturation. Using high-quality gas filters and original consumables helps resolve this issue and ensures consistent performance.

What is the advantage of a Split/Splitless injector?

These injectors provide flexibility: Split mode is used for concentrated samples to prevent column overload, while Splitless mode is ideal for trace-level analysis where maximum sensitivity is required.

What is Headspace chromatography?

Headspace chromatography is a technique where only the volatile components above a liquid or solid sample are analyzed. Systems such as the Thermo Scientific TriPlus 500 or Thermo Scientific TriPlus RSH autosamplers provide automated, highly precise headspace analysis while minimizing system contamination.

How does oven temperature affect separation?

Temperature controls the migration speed of analytes through the column. Programmed temperature ramping (temperature gradient) allows heavier components to elute faster while maintaining sharper peaks.

Why connect GC to a mass detector (GC-MS)?

Coupling GC with systems such as ISQ 7610, TSQ 9610, or GC Exploris enables not only separation of components but also precise identification of their molecular structure, which is essential in modern analytical laboratories.