Ion chromatography: A versatile technique for the analysis of beer

Importance of the topic

Ion chromatography is a powerful tool in beer analysis, enabling quantification of carbohydrates, alcohols, organic acids, and inorganic ions through high-resolution separation and sensitive electrochemical or conductivity detection. Its versatility addresses the complex matrix of beer components from brewing water quality to fermentation products, ensuring product consistency, flavor profiling, and quality control in brewing operations.

Study objectives and overview

This application note demonstrates the use of ion-exchange and ion-exclusion chromatography methods for five compound classes in beer: carbohydrates, alcohols, organic acids, inorganic anions, and inorganic cations. It outlines optimized separation conditions, detection modes, and gradient systems using a Thermo Scientific Dionex chromatographic platform.

Used instrumentation

• Thermo Scientific Dionex ICS system with gradient pump, ED40 electrochemical detector (pulsed amperometric and conductivity modes), eluent organizer, and Chromeleon CDS software
• CarboPac PA1 and PA100 columns for carbohydrates
• IonPac ICE-AS6 columns for alcohol and organic acid analysis
• IonPac AS11 column with ASRS suppressor for anion analysis
• IonPac CS12 column with CSRS suppressor for cation analysis
• Appropriate guard and trap columns (ATC-1, CG12, CTC-1)

Methodology

• Carbohydrates: Separated on CarboPac columns using hydroxide gradients and detected by pulsed amperometry with a gold electrode waveform to oxidize analytes and clean the electrode surface.
• Alcohols: Ethanol and glycerol resolved by ion-exclusion on ICE-AS6 with perchloric acid eluent and pulsed amperometry using a platinum electrode waveform.
• Organic acids: Low molecular weight acids separated by ion-exclusion on ICE-AS6 with heptafluorobutyric acid eluent and detected by suppressed conductivity.
• Inorganic anions: Anion-exchange on AS11 with hydroxide gradients and methanol modifier, detected by suppressed conductivity using ASRS suppressor.
• Inorganic cations: Cation-exchange on CS12 with methanesulfonic acid gradients, detected by suppressed conductivity using CSRS suppressor.

Key results and discussion

• Efficient separation of fermentable sugars (DP1–DP3) and higher malto-oligosaccharides (up to DP10–DP15) for wort and beer profiling.
• Clear resolution of ethanol and glycerol peaks, facilitating assessment of fermentation completeness and flavor impact.
• Baseline separation of key organic acids (e.g., pyruvate, lactate, acetate) enabling monitoring of fermentation pathways and flavor compounds.
• Simultaneous analysis of inorganic anions and weak organic acids with gradient elution, demonstrating high reproducibility (≤0.5% RT, ≤2% area) and linearity (r2 ≥0.999).
• Separation of major cations (Na+, NH4+, K+, Mg2+, Ca2+) and trace divalent metals with precision, supporting water quality control and mash pH optimization.

Benefits and practical applications

Consolidating multiple beer analytes on a single ion chromatography platform reduces equipment and analysis time, while providing high sensitivity and selectivity for quality control, process monitoring, and regulatory compliance.

Future trends and opportunities

• Real-time process control integration with automated ion chromatography systems in breweries.
• Development of miniaturized columns and new resin chemistries for faster on-line analysis.
• Coupling ion chromatography with mass spectrometry for comprehensive metabolomic and proteomic beer profiling.
• Adaptation to craft, nonalcoholic, and specialty beers for detailed characterization of novel ingredients.

Conclusion

Ion chromatography provides a versatile and robust analytical approach for comprehensive beer analysis, supporting the brewing industry in quality assurance, product development, and process optimization.