Spectrométrie Air Liquide

The fingerprint of stable isotopes, the ratio between stable isotopes in the same element.

In principle, the isotopes of an element in nature always occur in a fixed ratio. However, the ratios between isotopes in the same element (for example C13 and C12) can differ when the elements have a different geographical (or synthetic) origin. But external factors - such as climate or geographical conditions - can also give rise to differences. By measuring the isotope ratio of two stable isotopes of the same element and comparing it with other measurements, conclusions can be drawn about the origin of the measured samples.

The ratios between stable isotopes in the same element form a kind of fingerprint. This makes it possible, for example, to trace the origin of foodstuffs and medicines. The technology is also useful for atmospheric measurements of greenhouse gases or for geochemical measurements to optimize oil and gas drilling.

Air Liquide ALPHAGAZ™ reference gases with a traceable and specific stable isotope fingerprint in a single gas (eg CO2 or CH4) or in a composite gas mixture that may contain multiple components.

These gases allow the user to reliably measure the concentration of the stable isotope relative to the concentration of the element's most common stable isotope (delta values). The gases are available in different cylinder sizes and are suitable for different research applications.

Environmental research

Isotopic signatures for comprehensive understanding of pollution sources
Research of isotopic signatures (or isotopic fingerprints) is continuing to increase in various areas, including environmental studies. Isotopic signatures have become useful tools for a more comprehensive understanding of pollution sources. To aid in this essential research, Air Liquide has developed a range of reliable reference gases for isotope ratio measurements of Natural Air (with or without CO2) in standard packaging with Stable Isotope delta ratios of C, O, H, N and S elements.

Food authetication

 Food authentication

Isotopic analysis to track the origin of Food

Food and beverage adulteration is becoming more common and affects a wide range of products. To safeguard food and beverage production, the global scientific community developed enhanced analytical methods to guard against falsification; isotopic analysis is one of these methods. Isotopic analysis is primarily used in the food and beverage area to detect adulteration and to control the origins of ingredients.

Thanks to this method a wide range of food products such as wine, olive oil, fruit juices, vanilla, honey and spirits can be tested for the presence of adulteration. Air Liquide offers isotopically characterised gases with high analytical accuracy, required compositions and targeted isotope signatures that improves the reliability of your isotopic analysis.


Exploitation and production of oil and gas

Petroleum Geochemistry

Isotopic analysis to support accurate exploration and production development planning.

Gas stable isotopes are used to help understand the mechanisms of formation and compositional evolution of gas accumulations on a geologic and production time scale used for petroleum system modeling and reservoir management. Isotopic analysis maximises information derived from each well, reservoir or field and assists in accurate exploration and production development planning. Air Liquide has developed a unique standard product range of multi-component, natural gas calibration mixtures up to C5 species with specific delta 13C and delta 2H ratios.


Medical diagnostics

Medical Diagnostics

Stable Isotopes to support Breath Testing for fast, accurate and noninvasive testing of diseases

Breath testing is a growing application for fast, accurate and noninvasive testing of various diseases. Breath analyses based on Stable Isotope ratio of key molecules are being researched for non-invasive disease diagnosis and monitoring. Whether you are a clinical laboratory, testing laboratory or an OEM, Air Liquide provides a range of mixtures for equipment qualification, in order to obtain more accurate diagnostics.


Reference gases based on instrument manufacturer specifications

Air Liquide offers a range of reference gases specified by manufacturers (OEMs) of stable isotope measuring equipment.

Reference gases for Thermo Fisher Scientific - IRMS

Standardized reference gases with high analytical accuracy (gas composition and isotope ratio) for precise analysis and validation of Isotope Ratio Mass Spectroscopy (IRMS) instruments

Reference gases for Picarro - DRDS

Reference gases with high analytical accuracy for reliable analysis and validation of Cavity Ring-Down Spectroscopy (CRDS) analyser.

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