Analysis of Fourteen Organic Acids in Various Beverages Using the ACQUITY UPLC H-Class PLUS and ACQUITY QDa Mass Detector

Significance of the topic

Organic acids play a central role in beverage quality by contributing to taste, aroma, pH control, preservation, and authenticity assessment.

Monitoring these compounds supports consistent product specifications, fruit juice purity verification, and comprehensive quality control in food and beverage industries.

Objectives and study overview

This application note presents a single UPLC–MS method for the simultaneous analysis of fourteen organic acids in a variety of beverages including fruit juices, wines, energy drinks, sports drinks, and sparkling water.

The study evaluates chromatographic retention, peak shape, linearity, sensitivity, and method robustness, comparing a low-adsorption ACQUITY Premier CSH Phenyl-Hexyl Column with conventional approaches.

Methodology

Standard solutions of fourteen organic acids were prepared in water and diluted for calibration over 0.2–200 µg/mL. Beverage samples were diluted (10–500×), filtered, and injected directly.

A binary gradient of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B) was delivered over an 11-minute run at 50 °C with a 5 µL injection.

Detection employed negative electrospray ionization in single ion recording (SIR) mode to target deprotonated molecular ions [M–H]⁻ for each analyte.

Used Instrumentation

• ACQUITY UPLC H-Class PLUS System with FTN Sample Manager
• ACQUITY QDa Mass Detector
• ACQUITY Premier CSH Phenyl-Hexyl Column, 1.7 µm, 2.1×100 mm
• Empower 3 Chromatography Data System

Main results and discussion

The low-adsorption Premier column dramatically improved peak shape and sensitivity for metal-sensitive acids such as citric acid, with up to five-fold higher signal compared to standard hardware.

Baseline separation of isomeric acids (e.g., citric/isocitric, fumaric/maleic, aconitic isomers) was achieved despite shared m/z values, eliminating interferences without requiring ion-pair reagents or high-concentration buffers.

Analysis of commercial samples revealed characteristic profiles:

• Energy drinks: predominance of citric acid with secondary malic and lactic acids at low levels.
• Sports drink and sparkling water: citric and malic acids in sports drink; multiple low-level acids in water.
• Red wine: high tartaric, succinic, lactic acids plus minor shikimic, quinic, aconitic, and malic acids.
• Fruit juices: apple juice rich in malic and quinic acids; orange juice dominated by citric acid with multiple additional acids including ascorbic.

Reproducibility tests (50 injections) showed retention time RSD of 0.3% and area RSD of 1.9% for citric acid, confirming method robustness.

Benefits and practical applications

• Single-run analysis of fourteen organic acids without derivatization or ion-pair additives.
• Non-buffered mobile phase simplifies system maintenance and reduces background.
• Enhanced selectivity and lower detection limits using mass detection in SIR mode.
• Short analysis time (<11 min) and broad applicability across beverage classes.

Future trends and potential applications

Advancements in low-adsorption surfaces and compact mass detectors will continue to simplify polar analyte separations.

High-throughput QA/QC workflows in food and beverage labs can adopt similar UPLC–MS strategies for expanded panels of organic acids and related metabolites.

Integration with high-resolution MS may enable deeper profiling of minor organic constituents and adulteration markers.

Conclusion

The presented UPLC–QDa method delivers fast, reproducible, and sensitive analysis of fourteen organic acids across diverse beverage matrices using a streamlined, non-buffered gradient and low-adsorption hardware.

This approach enhances selectivity, reduces sample preparation complexity, and supports rigorous quality control and authenticity testing in industrial and research settings.

References

1. Li J., Zhang C., Liu H., Liu J., Jiao Z. Profiles of Sugar and Organic Acid of Fruit Juices: A Comparative Study and Implication for Authentication. Journal of Food Quality, 2020.
2. Camara M.M., Diez C., Torija M.E., Cano M.P. HPLC Determination of Organic Acids in Pineapple Juices and Nectars. Eur. Food Res. Technol., 1994.
3. Smith K.M., Rainville P.D. Utilization of MaxPeak High Performance Surfaces for Improved Separation and Recovery of Analytes Associated with the Tricarboxylic Acid Cycle. Waters Application Note, 2020.
4. Shah D. Fast, Accurate and Flexible LC-PDA Method for the Determination of Citric Acid in Beverages. Waters Application Brief, 2021.