Utilizing the Speed and Resolution of UPLC to Enhance the MS/MS Detection of HBCD and TBBP-A Diastereomers

Significance of the Topic

Persistent organic pollutants such as hexabromocyclododecane (HBCD) diastereomers and tetrabromobisphenol-A (TBBP-A) are widely used flame retardants that accumulate in environmental and biological matrices. Reliable, high-throughput analysis of these compounds is essential for monitoring their distribution and potential health risks.

Objectives and Study Overview

This study aimed to develop and validate a rapid UPLC-MS/MS method for the simultaneous detection of all five HBCD diastereomers and TBBP-A in marine samples. The method was benchmarked against an established HPLC-MS/MS protocol to assess improvements in resolution, run time, sensitivity, and laboratory throughput.

Methodology and Instrumentation

A Waters ACQUITY UPLC system equipped with a BEH C18 column (2.1 × 150 mm, 1.7 μm) was coupled to a Quattro Premier XE triple quadrupole mass spectrometer. Electrospray ionization in negative mode and multiple reaction monitoring (MRM) transitions were optimized for each analyte and corresponding 13C-labelled internal standards. A water-methanol gradient at a flow rate of 0.5 mL/min and column temperature of 60 °C achieved separation within a 10 min total run time. Data acquisition used MassLynx v4.1 and quantification was automated with TargetLynx.

Main Results and Discussion

The UPLC method achieved baseline separation of five HBCD diastereomers and TBBP-A with peak valleys below 10%, reducing run time from 25 min (HPLC) to 10 min. Peak widths decreased from ~0.6 min to ~0.15 min, boosting signal-to-noise ratios by up to fivefold. Calibration curves for TBBP-A and α, β, γ-HBCDs were linear (r2 > 0.999) over 5–600 ng/mL. Marine extracts spiked with 13C-standards demonstrated mean deviations of less than 20% compared to the reference method, confirming accuracy and precision.

Benefits and Practical Applications

• High throughput: Up to 6–12 samples per hour versus 2.4 samples/hour by HPLC.
• Enhanced sensitivity: Narrow peaks and improved signal-to-noise enable lower detection limits.
• Cost and environmental impact: Reduced solvent consumption lowers operational costs and chemical waste.
• Regulatory compliance: Method performance aligns with ISO 17025 requirements, supporting routine monitoring of flame retardants.

Future Trends and Opportunities for Application

Advances in ultra-high performance chromatography and hybrid mass analyzers will further decrease analysis times and enhance isomeric separation. Coupling UPLC with high-resolution mass spectrometry could provide deeper insight into transformation products and metabolites. The methodology can be adapted for other emerging persistent organic pollutants in diverse matrices, including wastewater and human tissues.

Conclusion

The optimized UPLC-MS/MS method delivers superior chromatographic resolution, sensitivity, and sample throughput for HBCD diastereomers and TBBP-A analysis compared to traditional HPLC approaches. Its validated performance ensures reliable quantification in environmental monitoring and risk assessment, while lowering costs and environmental impact.

References

• Morris S. et al. Environ. Sci. Technol. 2004;38(21):5497–5504.
• Sjödin A., Patterson J., Bergman A. Environ. Int. 2003;29(6):829–839.
• DEFRA Advisory Committee on Hazardous Substances. December 2006.
• Covaci A., Voorspoels S., Ramos L., Neels H., Blust R. J. Chromatogr. A. 2006.
• Cariou R. et al. J. Chromatogr. A. 2005;1100:144–152.
• Jin J., Peng H., Wang Y., Yang R., Cui J. Organohalogen Compd. 2006;68:85.
• Fernandes A., Driffield M. et al. Mol. Nutr. Food Res. 2007.
• Fernandes A., Driffield M. et al. Food Addit. Contam. 2007.
• Alaee M., Arias P., Sjödin A., Bergman A. Environ. Int. 2003;29(6):683–689.