Amines, C1 – C2 - Analysis of trace amines

Significance of the Topic

Amines, especially low molecular weight volatile C1–C2 species such as ammonia and methylamines, are important analytes in environmental monitoring, industrial process control and food safety. Their strong basicity and volatility make them challenging to retain and detect at trace levels using conventional GC stationary phases, demanding specialized column chemistries and detection techniques.

Objectives and Study Overview

This application note demonstrates a robust gas chromatographic method for the analysis of trace-level C1–C2 amines. The study evaluates the retention, peak shape and detection limits achieved with a porous polymer PoraPLOT column tailored for amines, and illustrates quantitative performance down to the nanogram range.

Methodology and Used Instrumentation

The analytical method combines on-column injection with an electrolytic conductivity detector (ELD) and a hydrogen carrier gas. Key parameters include:

• Column: Agilent PoraPLOT for Amines, 0.32 mm × 25 m, df = 10 μm porous polymer capillary (Part no. CP7591)
• Temperature program: 140 °C hold for 2 min, ramp at 10 °C/min to 250 °C
• Carrier gas: H₂ at 95 kPa (0.95 bar)
• Injector configuration: on-column
• Detector: electrolytic conductivity detector (ELD)
• Sample volume: 0.1 μL liquid injection

For applications requiring simultaneous measurement of amines, alcohols or water, an alternative 5 μm film CP-Sil 5 CB column operated around 30 °C is recommended.

Main Results and Discussion

The porous polymer column provided strong retention and inertness for all target amines. Sharp, well-resolved peaks were achieved at nanogram levels:

• Ammonia: 1.8 ng
• Methylamine: 3.4 ng
• Dimethylamine: 2.9 ng
• Trimethylamine: 2.9 ng
• Ethylamine: 3.4 ng

High retention prevented early elution and coelution issues common with siloxane phases, while ELD delivered sensitive, selective detection.

Benefits and Practical Applications

• High inertness minimizes adsorption and peak tailing of basic compounds
• Porous polymer matrix offers strong retention of highly volatile amines
• Nanogram-level detection supports trace analysis in environmental, industrial and food matrices
• On-column injection avoids sample discrimination and thermal decomposition

Future Trends and Applications

Advances in polymeric and ionic liquid column chemistries may further enhance selectivity for amines and related nitrogenous compounds. Coupling with mass spectrometry or advanced detector arrays could expand multiplexed analysis in complex matrices. Development of automated sample preparation and headspace techniques will streamline routine monitoring.

Conclusion

This application note validates the use of an Agilent PoraPLOT for Amines column combined with ELD for reliable trace analysis of C1–C2 amines. The method achieves sharp peaks, high sensitivity and reproducible quantitation at nanogram levels, offering a practical solution for laboratories tackling volatile basic analytes in challenging matrices.