High-speed Organic Acid Analysis Column: Shim-pack™ Fast-OA

Importance of the topic

Organic acid profiling is essential in fermentation processes and bio-industries to monitor microbial metabolism, optimize product yield, and ensure quality control. Rapid and reliable quantification of organic acids enables timely adjustments in fermenters and food production, improving consistency and safety.

Objectives and overview of the study

This application note introduces the Shim-pack Fast-OA high-speed ion-exclusion chromatography column designed for fast separation and quantification of organic acids. Key goals include reducing analysis time, achieving high selectivity in complex matrices, and supporting real-time monitoring in fermented foods and intestinal-flora research.

Methodology and instrumentation used

The study employed the Shim-pack Fast-OA column (7.8 mm I.D. × 100 mm) coupled with a pH-buffered conductivity detector (CDD-10AVP). Chromatographic conditions were:

• Mobile phase: 5 mmol/L p-toluenesulfonic acid with 20 mmol/L Bis-Tris and 0.1 mmol/L EDTA
• Flow rate: 0.8 mL/min
• Temperature: ambient
• Detection: post-column pH buffering + conductivity detection

A guard column (Shim-pack Fast-OA (G)) was used to protect the analytical column. Up to three Fast-OA columns can be connected in series for extended retention time when needed.

Main results and discussion

The Fast-OA column halved separation times compared to conventional 300 mm columns. Key findings:

• Separation of phosphoric, citric, and lactic acids in under 12 minutes, enabling real-time monitoring of yogurt fermentation.
• Analysis of seven short-chain fatty acids (pyruvic, succinic, formic, acetic, propionic, butyric, valeric) completed in under 10 minutes, demonstrating strong retention and peak resolution.
• Post-column pH-buffered conductivity detection provided high selectivity, minimizing interference from matrix impurities compared to UV detection at 210 nm.

Chromatograms showed clear, well-resolved peaks for target acids in culture media and food samples.

Benefits and practical applications

• High throughput: Rapid cycle times enhance sample throughput in QA/QC and research laboratories.
• Selectivity: Conductivity detection with pH buffering reduces false positives from co-eluting impurities.
• Flexibility: Modular column connections allow customization of retention based on analyte properties.
• Real-time control: Fast analysis supports on-line monitoring of fermentation and process optimization.

Future trends and potential applications

Emerging directions include coupling Fast-OA columns with mass spectrometry for structural identification of unknown metabolites, automated sampling for continuous process control, and expanded use in gut-microbiome studies to profile short-chain fatty acids in clinical and nutritional research.

Conclusion

The Shim-pack Fast-OA column offers a robust, high-speed solution for organic acid analysis in fermentation and biological studies. Its combination of rapid separation and selective conductivity detection addresses key challenges in industrial monitoring and research settings.

References

• Shimadzu C190-E234: High-speed Organic Acid Analysis Column: Shim-pack Fast-OA, First Edition, July 2019.