Sensitive online SPE determination of bisphenol A in water samples

Importance of the Topic

Bisphenol A (BPA) is a high-volume industrial monomer in polycarbonate and PVC production and exhibits endocrine-disrupting effects at very low concentrations. Sensitive monitoring of BPA in water, particularly drinking water, is crucial to assess exposure and ensure compliance with health guidelines.

Objectives and Study Overview

This work presents an automated online solid phase extraction (SPE) coupled to high-performance liquid chromatography (HPLC) method for quantifying trace levels of BPA in water samples. The goal is to minimize manual handling, reduce analysis time, and achieve reliable recovery at sub-ng/mL concentrations.

Methodology Summary

The procedure involves six SPE steps: conditioning the extraction column with water, loading the sample at 3 mL/min, washing with water, transferring the SPE cartridge into the HPLC flow path, eluting the analyte with isocratic 50:50 acetonitrile/water at 0.6 mL/min, and reconditioning the SPE column between injections. Detection is performed at 227 nm over a 5 min runtime.

Used Instrumentation

• AZURA P 6.1L LPG pump (10 mL/min)
• AZURA AS 6.1L autosampler
• AZURA MWD 2.1L multi-wavelength detector with LightGuide flow cell
• AZURA CT 2.1 column thermostat
• AZURA ASM 2.2L assistant with multi-position valves and dedicated pump head
• Vertex Plus analytical column (100 × 3 mm, Eurospher II 100-3 C18)
• Vertex Plus SPE column (30 × 4 mm, Eurospher II 100-3 C18)

Main Results and Discussion

Calibration by direct injection followed by online SPE yielded recovery rates of approximately 93% for BPA concentrations between 0.07 and 1 ng/mL. In fortified drinking water samples at 0.1 ng/mL, recovery reached 98% after optimizing the extraction time. The method demonstrates consistent performance and sensitivity suitable for routine monitoring of ultra-trace BPA.

Benefits and Practical Applications

• Automation reduces manual preparation time and cross-contamination risk.
• Sensitivity at sub-ng/mL levels meets regulatory requirements for drinking water.
• Short analysis cycles and online SPE increase sample throughput for environmental and quality control laboratories.

Future Trends and Potential Applications

The online SPE-HPLC approach can be extended to other trace organic contaminants by selecting appropriate sorbents and chromatographic conditions. Coupling with mass spectrometry detection could further enhance selectivity and lower detection limits in complex matrices.

Conclusion

The developed online SPE-HPLC method provides rapid, sensitive, and reproducible determination of bisphenol A in water samples. Its high throughput and low manual intervention make it ideal for continuous environmental monitoring and compliance testing.

References

1. Chen L., Wang H., Zeng Q., Xu Y., Sun L., Xu H., Ding L. Online Coupling of Solid-Phase Extraction to Liquid Chromatography—A Review. Journal of Chromatographic Science. 2009;47.
2. Jordáková I., Dobiás J., Voldřich M., Poustka J. Determination of Bisphenol A, Bisphenol F and related diglycidyl ethers from food cans using Gas Chromatography–Mass Spectrometry. Czech Journal of Food Science. 2003;21(3):85–90.
3. Umweltbundesamt. Bisphenol A – Wir haben ein Problem. Telegramm Umwelt + Gesundheit. 04/2008.
4. Umweltbundesamt. Bisphenol A Massenchemikalie mit unerwünschten Nebenwirkungen. July 2010.