Development of An UHPLC Method for Simultaneous Determination of Thirteen Bisphenols in Milk Samples

Significance of the Topic

Bisphenols such as BPA and BPF and their diglycidyl esters are widely used in food contact materials and can migrate into milk products under certain conditions posing health risks. Regulatory authorities in the EU and the US have set strict limits on bisphenol migration due to estrogenic effects and potential endocrine disruption. A reliable, fast, and sensitive analytical method is essential for monitoring these contaminants in dairy matrices and ensuring food safety.

Objectives and Overview of the Study

This study aims to develop and validate a rapid ultrahigh performance liquid chromatography method with fluorescence detection for simultaneous quantification of thirteen bisphenol compounds in milk. The method is designed to achieve high sensitivity, accuracy, and reproducibility to meet regulatory requirements and support routine food safety analysis.

Methodology

• Preparation of mixed standard solutions containing thirteen bisphenols at concentrations ranging from 5 to 2000 µg/L
• Evaluation of method performance using blank and spiked milk samples at 100 and 1000 µg/L levels
• Construction of multi-point calibration curves with twelve concentration levels to assess linearity
• Calculation of limits of detection and quantification based on signal-to-noise criteria

Instrumentation

• UHPLC system Nexera X2 equipped with RF-20Axs fluorescence detector
• Shim-pack HR-ODS column 250 x 3.0 mm with 3 µm particle size
• Mobile phase of water and acetonitrile in a gradient from 30 to 85 percent organic over 43 minutes
• Detection at excitation 235 nm and emission 317 nm, column at 30°C, flow rate 0.4 mL/min, injection volume 10 µL

Main Results and Discussion

• Complete separation of thirteen bisphenols within 43 minutes and baseline resolution of critical isomeric pairs
• Excellent linearity with correlation coefficients above 0.999 for all analytes
• Limits of detection between 0.4 and 1.6 µg/L and quantification limits between 1.5 and 4.7 µg/L
• Precision with RSDs below 2.3 percent at 5 µg/L and below 1 percent at 100 µg/L
• Recoveries in spiked milk ranging from 90 to 130 percent for early eluting compounds and decreasing to 37–66 percent for late eluting analytes, indicating matrix effects

Benefits and Practical Applications

This UHPLC method offers a rapid workflow and low detection limits suitable for routine monitoring of bisphenol contamination in milk. High accuracy and precision make it a robust tool for quality control laboratories and regulatory compliance testing. Its simplicity and speed allow efficient screening of multiple bisphenol derivatives in a single run.

Future Trends and Potential Applications

• Extension to other food matrices such as beverages and packaged foods
• Integration with mass spectrometry detection to expand analyte scope and improve specificity
• Development of automated sample preparation and online extraction to increase throughput
• Application in large-scale biomonitoring studies to assess consumer exposure to bisphenols

Conclusion

A fast and sensitive UHPLC-fluorescence method was successfully developed for simultaneous determination of thirteen bisphenols in milk. The method demonstrates excellent linearity, low detection limits, and reliable quantification, supporting effective monitoring and risk assessment of bisphenol contaminants in dairy products.

References

• Jan Poustka et al, Czech Journal of Food Sciences, Vol 25, No 4, 221–229 (2007)
• Ivana Poustková et al, European Food Research and Technology, 219, 534–539 (2004)
• US Food and Drug Administration Food Additive Regulations for Bisphenol A in Infant Formula Containers
• Shimadzu Corporation Application News No L408 (2013)