HPLC determination of biogenic amines in beer by AQC derivatization

Significance of the Topic

Biogenic amines in beer are important indicators of microbial quality and safety. Their accumulation during fermentation or through raw materials can signal potential spoilage or health concerns, making sensitive and reliable detection methods essential.

Objectives and Study Overview

This study aimed to establish a robust reversed-phase HPLC method combined with pre-column derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) for the quantitation of nine biogenic amines in beer matrices. Ten commercial beer samples were analyzed to assess method applicability.

Methodology and Instrumentation

AQC derivatization was performed in borate buffer at 55 °C, followed by dilution and injection into an Accucore aQ C18 column (2.1×100 mm, 2.6 µm) on a Thermo Scientific Vanquish Core HPLC system. Gradient elution used 50 mM ammonium acetate (pH 5.0) and acetonitrile. Detection employed fluorescence (excitation 248 nm, emission 298 nm) for most amines and UV at 248 nm for tryptamine. Instrumentation:

• Vanquish Core Quaternary HPLC System
• Accucore aQ C18 column 2.1×100 mm, 2.6 µm
• Vanquish Diode Array Detector CG and Fluorescence Detector F
• Chromeleon 7.3 for data acquisition

Main Results and Discussion

The method achieved clear separation of nine AQC-labeled amines. Fluorescence detection provided high sensitivity except for tryptamine, which was better detected by UV due to quenching effects. In ten beer samples, agmatine, tyramine, putrescine and cadaverine were quantifiable at low mg/L levels. Histamine coeluted with a matrix interference and was below the limit of quantitation in all samples. Tryptamine and spermidine were undetectable.

Benefits and Practical Application of the Method

• Rapid AQC derivatization in under 15 minutes
• High selectivity and sensitivity for multiple amines
• Robust workflow suitable for quality control in breweries and analytical labs
• Applicability to diverse beer types without extensive sample cleanup

Future Trends and Potential Applications

Emerging directions include coupling AQC-HPLC with mass spectrometry for enhanced specificity, extending the method to other fermented beverages and food matrices, automating derivatization for high-throughput screening, and developing portable devices for on-site monitoring.

Conclusion

This study presents a validated, user-friendly HPLC-FLD/UV approach for comprehensive profiling of biogenic amines in beer, offering a valuable tool for quality assurance and food safety monitoring.

Reference

• Izquierdo-Pulido M. et al. Biogenic Amines in European Beers, J. Agric. Food Chem., 1996, 44(10), 3159–3163.