Analysis of Primary Amines

Significance of the Topic

The analysis of underivatized primary amines is critical in environmental monitoring, pharmaceutical quality control, and food safety. Accurate separation and quantitation of volatile amines support regulatory compliance, process optimization, and identification of trace-level contaminants.

Objectives and Overview

This application note describes a gas chromatographic method with flame ionization detection for nine common primary amines. The goal is to achieve rapid, reliable separation without chemical derivatization, using a specialized polar column.

Methodology and Instrumentation Used

• Instrument: Gas chromatograph equipped with flame ionization detector at 300 °C
• Column: SH-35 Amine, 30 m x 0.53 mm I.D., film thickness 1.00 µm (P slash N 227-36292-01)
• Column temperature: 35 °C hold for 5 min
• Injector: Split mode 1:10, injection volume 1 µL, injector temperature 250 °C
• Carrier gas: Helium at constant pressure, linear velocity 35.7 cm/s
• Sample: Primary amines at 50 µg/mL in water, on-column concentration
• Dead time: 1.9 min

Main Results and Discussion

The method delivers baseline separation of nine amines, including methylamine, dimethylamine, trimethylamine, ethylamine, isopropylamine, tert-butylamine, n-propylamine, diethylamine, and sec-butylamine. Early eluters such as methylamine are resolved within minutes, and the total run time remains under 15 minutes. Detector response is linear across the tested concentration range, and the system shows consistent retention times with low drift.

Benefits and Practical Applications

• No derivatization simplifies sample preparation and reduces analysis time.
• High sensitivity of FID supports trace-level detection.
• Robust column chemistry ensures repeatable performance for basic analytes.
• Wide applicability in water quality testing, industrial process control, and food safety screenings.

Future Trends and Applications

Emerging needs include integration with mass spectrometric detection for enhanced selectivity, miniaturized GC systems for field analysis, and automated sample handling to increase throughput. Advances in column materials could further improve peak shape for highly polar amines.

Conclusion

The SH-35 Amine GC-FID method offers a fast, reliable, and derivatization-free approach for quantifying primary amines in aqueous matrices. Its simplicity and performance make it suitable for routine laboratory use in diverse analytical settings.

Reference

Shimadzu Corporation, ERAS-1000-0459, First Edition September 2023