Anions and cations in beer

Significance of the Topic

Ion chromatography (IC) provides a rapid and reliable approach to monitor ionic profiles in beer, a critical factor affecting taste, stability and overall quality. Controlling anion and cation concentrations ensures consistent sensory attributes in large-scale production and compliance with food safety regulations.

Study Objectives and Overview

This application note describes a streamlined workflow for simultaneous determination of major anions and cations in beer using a two-channel IC system. Key goals include minimizing manual sample preparation, achieving accurate quantification across wide concentration ranges, and delivering high throughput in quality control laboratories.

Methodology and Instrumentation Used

Samples from various brewers were automatically filtered and diluted via inline ultrafiltration.

• Two analytical channels run in parallel under isocratic conditions for anions and cations.
• Suppressed conductivity detection for anions and non-suppressed conductivity for cations.
• Logical dilution and Metrohm intelligent Partial Loop Injection (MiPT) ensure calibration accuracy across 1:10 000 concentration ranges.

The main hardware components comprised:

• 930 Compact IC Flex with column oven, sequential suppression and built-in degasser
• IC Conductivity Detector with high temperature stability and dynamic range
• Metrosep A Supp 10-100/4.0 and Metrosep C 6-150/4.0 separation columns
• 858 Professional Sample Processor, 941 Eluent Production Module and 800 Dosino
• Inline dilution and ultrafiltration accessories
• MagIC Net software for system control, calibration, logical dilutions and data evaluation

Main Results and Discussion

Analysis of a representative pilsner revealed:

• Anions: chloride (~229 mg/L), phosphate (~352 mg/L), nitrate (~5 mg/L) and sulfate (~60 mg/L); sulfite also detected within a single run.
• Cations: potassium (~365 mg/L) as the dominant ion, with lower levels of sodium (~13 mg/L), calcium (~53 mg/L) and magnesium (~56 mg/L).

These data illustrate how specific ions influence bitterness, astringency and sweetness in beer, and demonstrate robust separation and detection within standard run times.

Benefits and Practical Applications

This IC protocol offers:

• Simultaneous multi-ion determination in one automated run
• Reduced manual handling through inline ultrafiltration and automatic dilution
• Accurate calibration across broad concentration ranges via MiPT and logical dilution
• High throughput suitable for routine QA/QC in breweries

Future Trends and Potential Applications

Advances may include integrating real-time process monitoring directly on the brew line, coupling IC with mass spectrometry for trace-level detection of flavor-active ions, and expanding to other beverage matrices such as soft drinks and fermented products.

Conclusion

The described two-channel IC method streamlines beer analysis by combining inline sample preparation, simultaneous anion and cation determination, and intelligent software features. The approach enhances throughput, precision and operational efficiency for quality control in beverage production.

References

• Metrohm AG Application Note AN-D-002, Anions and Cations in Beer: Streamlining Beverage Analysis with Ion Chromatography