Issues with analyzing noble gases using gas chromatography with thermal conductivity detection

Area of Science:

• Analytical Chemistry
• Metrology
• Gas Analysis

Background:

• Noble gases (neon, argon, krypton, xenon) have diverse industrial and medical applications.
• Accurate determination of noble gas mixture composition is vital for quality control and safety.
• Existing gas standards have shown discrepancies among National Metrology Institutes.

Purpose of the Study:

• To evaluate the accuracy of noble gas mixture standards.
• To compare analytical and gravimetric values of noble gas amount-of-substance fractions.
• To identify factors affecting measurement accuracy, including standard composition and carrier gases.

Main Methods:

• Comparative analysis of noble gas mixtures.
• Gravimetric determination of noble gas amount-of-substance.
• Analytical measurements using different standard compositions (binary vs. multi-component) and carrier gases (hydrogen, helium, nitrogen).

Main Results:

• Binary standards led to significant discrepancies (0.7% to 3.8%) between analytical and gravimetric values.
• Multi-component standards (including all four noble gases) achieved agreement within 0.05% relative.
• Carrier gases influenced the differences between analytical and gravimetric assignments.

Conclusions:

• Multi-component noble gas standards are superior to binary standards for accurate mixture analysis.
• The choice of carrier gas impacts the accuracy of noble gas quantification.
• Improved gas standards are necessary for reliable industrial and medical applications of noble gas mixtures.