Determination of Catechins and Phenolic Acids in Red Wine by Solid Phase Extraction and HPLC

Importance of the Topic

Polyphenols such as catechins and phenolic acids contribute to the color, taste, and health-promoting antioxidant properties of plant-derived foods and beverages. In red wine, these compounds influence organoleptic qualities and stability. Reliable quantitation of these polar analytes is critical for quality control, nutritional studies, and research into the health benefits of dietary polyphenols.

Study Objectives and Overview

This study aimed to develop a fast, robust HPLC method for simultaneous determination of nine catechins and phenolic acids in red wine. Sample preparation employed solid-phase extraction (SPE) on HyperSep Retain PEP cartridges. Quantification was achieved via matrix-matched calibration of spiked wine extracts. Separation utilized gradient elution on a core-shell Accucore PFP column with UV detection at 280 nm.

Methodology and Instrumentation

Sample Preparation and SPE Optimization:
A red Bonarda Shiraz wine was diluted 1 + 2 with water, spiked at six concentration levels, and processed on HyperSep Retain PEP cartridges (200 mg/3 mL). Cartridges were conditioned with methanol and water, loaded with sample, washed with water + 0.1% formic acid and 20% methanol + 0.1% formic acid (optimal wash), then eluted with four 1 mL portions of 100% methanol + 0.1% formic acid. Elution profiles demonstrated minimal analyte loss during washing and complete recovery in 100% methanol.

Chromatographic Conditions:

• System: Thermo Scientific Accela UHPLC
• Column: Accucore PFP, 2.6 µm, 100 × 2.1 mm
• Mobile Phase A: Water + 0.1% formic acid; B: Acetonitrile + 0.1% formic acid
• Gradient: 2% B (0–0.1 min) to 65% B (7.1 min), then to 95% B (7.2–7.9 min), returning to 2% B by 8.0 min; total runtime 10 min
• Flow Rate: 0.4 mL/min; Column Temp: 30 °C; Detection: UV at 280 nm; Injection: 1 µL

Main Results and Discussion

The method achieved baseline separation of nine structurally similar analytes in approximately five minutes. Matrix-matched calibration curves exhibited excellent linearity (correlation coefficients > 0.995). Recoveries ranged from 89% to 96%, and accuracy values were within 92%–111% across tested concentration levels. Representative chromatograms confirm efficient resolution, while calibration plots demonstrate reliable quantification.

Benefits and Practical Applications

This SPE-UHPLC approach delivers rapid, selective analysis valuable for wine quality assurance, research on polyphenol content, and routine food analysis. The core-shell PFP chemistry enhances selectivity for aromatic polar compounds, and the Retain PEP sorbent ensures high recovery and broad pH stability.

Future Trends and Applications

Future developments may include coupling with mass spectrometry for improved specificity, automation of SPE-UHPLC workflows for high-throughput analysis, application to other food and botanical matrices, and integration into metabolomics studies and real-time process monitoring in winemaking.

Conclusion

The combined use of HyperSep Retain PEP SPE and an Accucore PFP core-shell column provides a fast, accurate, and reproducible method for quantifying nine catechins and phenolic acids in red wine. Its simplicity and robustness make it suitable for both research and routine quality control applications.

References

1. H.S. Lee, B.W. Widmer. Phenolic compounds. In: L.M.L. Nollet, ed. Handbook of Food Analysis. Marcel Dekker, 1996, pp. 821-894.
2. M. del Alamo, L. Casado, V. Hernandez, J.J. Jimenez. J. Chromatogr. A, 2004, 1049, 97-105.