Dumas Principle - Helium-Free Nitrogen Analysis

Helium is commonly used as an inert carrier gas for nitrogen and protein analyzers and, until recently, was the only choice for Dumas analyzers. A new generation of future-proof N/protein analyzers allows the use of alternative carrier gases such as CO₂ and Argon.

Image Credit: Elementar Americas Inc.

Nitrogen and protein analysis using the Dumas principle utilizes the quantitative conversion of analytes into well-defined gaseous species at elevated temperatures in the presence of appropriate reagents and elemental oxygen.

Excess oxygen from the combustion phase often binds to metals such as tungsten or copper (reducing metals) before the chromatographic separation of the combustion gases, enabling the detection of N₂ with a thermal conductivity detector (TCD).

Helium is commonly used as an inert carrier gas for nitrogen and protein analyzers and was the only choice for Dumas analyzers until recently.

There has been a lack of alternative approaches primarily due to limitations in thermal conductivity detectors being able to handle the minor differences in conductivity between N₂ and other inert gases, while this conductivity difference is substantial and easily recognizable in helium.

However, helium shortages have occurred more often in recent years, leading to increasing prices. US policies on Federal Helium Reserves have changed, as well as the cost of extracting helium from natural gas, the most common source of helium.

In response to this, Elementar has created the next generation of future-proof nitrogen and protein analyzers using proprietary EAS REGAINER^® technology and alternative carrier gases, such as carbon dioxide for the rapid N exceed^® and argon for the rapid MAX N exceed, without impacting analysis performance.

Download the Technical Note to learn more about helium-free nitrogen and protein analysis.

Image Credit: Elementar Americas Inc.

Image Credit: Elementar Americas Inc.

This information has been sourced, reviewed and adapted from materials provided by Elementar Americas Inc.

For more information on this source, please visit Elementar Americas Inc.