Determination of Ethanolamines in water as per ASTM D-7599 by LCMS-8045

Significance of the Topic

Direct measurement of ethanolamines in water is essential due to their widespread industrial applications and the risk of forming carcinogenic nitrosamines. Monitoring trace levels supports regulatory compliance and safeguards environmental and human health.

Objectives and Overview of the Study

This study presents the development and validation of an LC-MS/MS method, compliant with ASTM D-7599, for simultaneous quantitation of diethanolamine, triethanolamine, N-methyldiethanolamine, and N-ethyldiethanolamine in water. A deuterated surrogate (diethanolamine-D8) ensures accurate recovery.

Methodology and Instrumentation

Sample preparation involves spiking water samples with surrogate standard, filtration through a 0.45 µm PVDF syringe filter, and direct UHPLC injection.

• UHPLC: Shimadzu Nexera system with Shim-pack Velox HILIC column (100 mm × 2.1 mm I.D., 2.7 µm), gradient elution of acetonitrile, water, and 20 mM ammonium acetate at 0.4 mL/min, 35 °C, 5 µL injection.
• Mass spectrometer: Shimadzu LCMS-8045 with electrospray ionization in positive mode (nebulizing gas 3 L/min, drying gas 10 L/min, DL 150 °C, heat block 200 °C, heater off) and optimized MRM transitions for each analyte and surrogate.

Main Results and Discussion

Calibration was linear from 5 to 1000 ppb (r2 > 0.99). Limits of detection were set at 5 ppb for all analytes due to matrix suppression. Recovery studies at 50, 100, and 250 ppb yielded 97–103% accuracy. Surrogate-spiked samples confirmed method robustness, and no target analytes were detected above LOD in tested environmental water samples.

Benefits and Practical Applications

The method offers high sensitivity and selectivity, minimal sample preparation, and rapid analysis suitable for environmental monitoring, quality control in manufacturing, and regulatory compliance.

Future Trends and Potential Applications

Further advancements may include coupling with high-resolution mass spectrometry for broader analyte screening, miniaturized sampling techniques, automated sample handling, and expansion to complex matrices in pharmaceutical or wastewater analysis.

Conclusion

An ultra-sensitive, ASTM D-7599-compliant LC-MS/MS protocol on the Shimadzu LCMS-8045 was established for ethanolamine determination in water, demonstrating reliable quantitation at trace levels with robust recovery and linearity.

Reference

• ASTM D-7599: Standard Test Method for Determination of Ethanolamines in Water by LC-MS/MS, ASTM International.