Nonylphenol, Bisphenol A, 4-tert-Octylphenol, Nonylphenol Monoethoxylate, and Nonylphenol Diethoxylate on Rxi®-XLB by ASTM D7065-11

Importance of the Topic

Phenolic compounds such as nonylphenol, bisphenol A and 4-tert-octylphenol, along with their ethoxylates, are recognized endocrine disruptors. Accurate monitoring of these substances is essential for environmental protection, regulatory compliance and public health, particularly in water, soil and industrial effluents.

Objectives and Study Overview

The primary goal was to establish a robust GC-MS method conforming to ASTM D7065-11 for the simultaneous separation and quantitation of nonylphenol, bisphenol A, 4-tert-octylphenol, nonylphenol monoethoxylate and nonylphenol diethoxylate. The study evaluated chromatographic performance, sensitivity and reproducibility using deuterated internal standards.

Methodology and Instrumentation

• Instrument: Agilent 7890B GC coupled with 5977A MSD
• Column: Rxi®-XLB, 30 m × 0.25 mm ID × 0.25 µm film thickness
• Sample Preparation: Standards in dichloromethane with internal standards (acenaphthene-d10, phenanthrene-d10, chrysene-d12)
• Injection: 1 µL split (10:1) using premium 4 mm precision liner with wool at 250 °C
• Oven Program: 45 °C (1 min) to 305 °C at 8 °C/min (hold 1 min)
• Carrier Gas: Helium, constant flow at 1.4 mL/min
• Detection: MS in scan mode (35–550 amu at 5.4 scans/s), EI ionization
• Transfer Line: 300 °C; Source: 300 °C; Quadrupole: 150 °C

Key Results and Discussion

The method achieved baseline separation of all target analytes within 30 minutes. Retention times ranged from 16.2 min for acenaphthene-d10 to 29.1 min for chrysene-d12. Detector response was linear across on-column amounts from 2.5 ng to 64 ng. Isomeric ethoxylates were clearly resolved with sharp peak shapes and minimal matrix interference, demonstrating high method robustness.

Benefits and Practical Applications

• High sensitivity and specificity for phenolic endocrine disruptors in complex matrices
• Full compliance with ASTM D7065-11 ensures reproducibility and regulatory acceptance
• Simplified sample preparation and reliable quantitation using deuterated internal standards
• Applicable to environmental monitoring, wastewater analysis and industrial QA/QC laboratories

Future Trends and Potential Applications

Advances may focus on faster analyses via shorter columns or accelerated temperature ramps, automated sample handling, and coupling with high-resolution mass spectrometry for enhanced detection limits. Field-deployable GC-MS systems could expand on-site environmental monitoring and process control.

Conclusion

The described GC-MS procedure on an Rxi®-XLB column offers a fast, reliable and sensitive approach for quantifying nonylphenol, bisphenol A, 4-tert-octylphenol and related ethoxylates in accordance with ASTM D7065-11. Its robustness and regulatory alignment make it a valuable tool for environmental and industrial laboratories.

References

No references provided in the source document.