C1 – C3 amines - Analysis of volatile amines in DMA

Importance of the Topic

Volatile amines such as ammonia, methylamines and dimethylamines are key intermediates in the chemical and pharmaceutical industries. Accurate monitoring of these compounds in process streams is essential for product purity, safety and regulatory compliance. Developing a rapid, robust analytical method enables real-time quality control and reduces downtime in continuous production.

Objectives and Study Overview

This application note describes an online gas chromatographic method tailored for analysis of C1–C3 amines dissolved in dimethylamine (DMA) streams. The study aimed to achieve fast separation, low detection limits (10–50 ppm) and high sample throughput (approximately 250 injections/week) for quality monitoring of methylamine products.

Used Instrumentation

• Gas chromatograph with dual split injectors
• Two Agilent CP-Volamine fused-silica capillary columns (0.32 mm × 60 m, 5 µm film thickness)
• Flame ionization detector (FID)
• Micro-thermal conductivity detector (µTCD)
• Helium carrier gas supply

Methodology and Analytical Conditions

Samples (1 µL liquid gas) were injected in split mode (1:15) at 180 °C. The column temperature program started at 40 °C (10 min), ramping at 20 °C/min to 250 °C. Helium was maintained at 100 kPa. FID and µTCD operated at 250 °C. The inert CP-Volamine phase offered minimal interaction with polar amines, delivering sharp, symmetric peaks (MMA peak symmetry > 0.8) and extended column lifetime.

Main Results and Discussion

Simultaneous analysis on FID and µTCD provided complementary sensitivity for nitrogen-containing compounds. Key analytes were baseline separated: ammonia, water, methylamine, methanol, dimethylamine, ethylamine and trimethylamine. Typical concentration levels observed in bulk DMA streams ranged from 575 ppm (methanol) to 2000 ppm (water). The method demonstrated reproducible retention times, reliable quantification and detection limits suited for process control.

Benefits and Practical Applications

• High throughput: up to 250 analyses per week without manual sample preparation
• Robust quantification: low detection limits for trace impurities
• Extended column life: inert film reduces degradation by amines
• Dual detection: FID for hydrocarbons and µTCD for permanent gases and ammonia
• Real-time monitoring: immediate feedback for plant operation and product quality

Future Trends and Opportunities

Advances in column chemistry and detector miniaturization will support on-site micro-GC systems for field analysis. Integration with mass spectrometry could expand compound coverage, while automated sampling and AI-driven data interpretation will further accelerate decision making. Process analytics may evolve toward fully self-optimizing control loops using continuous GC data.

Conclusion

The described GC method with Agilent CP-Volamine columns delivers a fast, sensitive and reliable solution for analysis of volatile amines in DMA. Its high throughput and robustness make it suitable for continuous process control, ensuring consistent product quality and operational efficiency.

Reference

• Dr. F. de Boever, UCB Research Center Drogenbos
• Dr. G. Baele, UCB Gent, Belgium
• Agilent Technologies, Application Note A01564, 2011