Amines

Importance of the Topic

Analysis of trace amines in complex matrices is critical for environmental monitoring, industrial process control, and quality assurance. Highly selective separation techniques are essential to resolve closely related basic compounds and deliver reliable quantitative data.

Aims and Study Overview

This application note evaluates the performance of a non-polar, base-deactivated bonded phase (CP-Sil 8 CB for Amines) for the gas chromatographic separation of common aliphatic and heterocyclic amines present at low levels in an ethanolic matrix. The goal is to demonstrate resolution, reproducibility, and practical conditions for routine analysis.

Methodology and Used Instrumentation

The analytical procedure employs capillary gas chromatography with the following parameters:

• Column: CP-Sil 8 CB for Amines, 0.25 mm × 30 m, 0.5 μm film thickness
• Oven program: 50 °C ramped to 86 °C at 4 °C/min, then to 246 °C at 10 °C/min
• Carrier gas: helium at 62 kPa (0.82 bar)
• Injector: split mode at 150 °C
• Detector: thermal conductivity detector at 250 °C
• Sample: 1 μL of approximately 0.2 % amines in ethanol

Main Results and Discussion

The CP-Sil 8 CB phase provided baseline separation of water, ethanol, and ten amine compounds in under 20 minutes. Identified peaks include:

1. Water
2. Ethanol
3. Ethylenediamine
4. Triethylamine
5. Methylethylenediamine
6. Ethylethylenediamine
7. Morpholine
8. Piperazine
9. Diethylenetriamine
10. Triethylenetetramine

Retention order reflects increasing molecular weight and polarity. The base-deactivated stationary phase minimized peak tailing and improved symmetry for basic analytes.

Benefits and Practical Applications

The method offers:

• Robust separation of aliphatic and heterocyclic amines in a single run
• Reduced secondary interactions due to base deactivation
• Simplified sample preparation for trace-level determination
• Applicability to environmental, petrochemical, and industrial quality control

Future Trends and Opportunities

Advances in stationary phase chemistry may yield even greater selectivity for structurally similar amines. Coupling to mass spectrometric detection will enhance sensitivity and confirmation capabilities. Miniaturized and automated GC systems promise higher throughput and lower solvent consumption.

Conclusion

The CP-Sil 8 CB for Amines column delivers efficient and reproducible separation of ten common amines and low-molecular-weight interferences within an ethanol matrix. Its non-polar, base-deactivated nature makes it a valuable tool for routine analysis in various laboratories.

References

Agilent Technologies, Application Note A01317, October 2011