Gas Composition Analysis

Gas Compo­sition Analysis

At Isolab, we offer a complete and in-depth compositional analysis of natural gases, biogases, and other related gas types. This analysis serves as the foundation for further isotopic studies, quality assessments, and characterization of gas sources.

A box of gas samples

What We Analyze

Our standard gas composition analysis includes the following components:

  • Hydrocarbons:

    Methane (CH₄), Ethane (C₂H₆), Ethene (C₂H4), Propane (C₃H₈), Propene (C₃H6),  normal- and and iso-Butane (C₄H₁₀), normal- and iso-Pentane (C₅H₁₂), and the sum of higher hydrocarbons (C₆⁺)

  • Inorganic gases:

    Nitrogen (N₂), Hydrogen (H₂), Carbon dioxide (CO₂), Carbon monixide (CO), Argon (Ar), Oxygen (O₂) and Hydrogen sulfide (H₂S)

Detection limits are in the low ppm range (as low as 1 ppm for hydrocarbons), depending on the component (click here for detailled detection limits).

Optionally, we offer a separate analysis for the detection of Helium and/or the measurement of low concentrations of hydrogen.

GC-column for composition analysis

Analytical Setup

For the measurement of gas composition, we use a home build system, consisting of two modern Agilent gas chromatographs equipped with three analytical columns and 3 detectors. The system is optimized to measure a wide range of gas sample types as well as for the injection of very small volumes.

The system is calibrated multiple times a day with several gas standards.

Sample Types

We accept a wide variety of gas samples, such as:

Preferred Containers

We support a broad selection of sample containers and conditions, but for best results, we recommend:

  • Swagelok gas cylinders
  • Isotube or isojar containers
  • Gasbags (we prefer the ones from Calibrated Industries)
  • Isoflasks (for water-dissolved gases)
  • Labco vials (for low-volume gas samples)

For full guidelines on sample containers, please click here.

Conditions

Ideal conditions are samples that are pressurized to 5-10 bars in cylinders of 300-500ml. However, we can handle samples with a pressure between ca. 0 and 100 bars and volumes down to a few ml in various containers.

Why Perform a Compositional Analysis?

Gas composition analysis is crucial for:

  • Assessing sample integrity
  • Enabling accurate isotope measurements
  • Process monitoring
  • Determining gas origin or type
  • Detecting contamination or mixing
  • Quantifying gas wetness

Next Step: Isotopic Analysis

Following compositional analysis, Isolab offers full stable isotope measurements for gases, including carbon, hydrogen, and oxygen isotopes (bulk and compound-specific).

Learn more about our isotope services →