Analysis of Glyphosate, AMPA, and Glufosinate in Water Using UPLC-MS/MS

Importance of the Topic

Monitoring glyphosate, AMPA and glufosinate in water is critical to ensure compliance with regulatory standards and to assess environmental impact of widely used herbicides. This method addresses challenges related to high polarity, metal complexation and trace detection in drinking, surface and ground waters.

Study Objectives and Overview

The goal was to develop a specific, rapid and cost-effective UPLC-MS/MS method for simultaneous quantification of glyphosate, AMPA and glufosinate in water samples. The approach employs FMOC derivatization without solid phase extraction and leverages UniSpray ionization on a Waters ACQUITY UPLC I-Class system coupled to a Xevo TQ-XS mass spectrometer.

Methodology and Instrumentation

Sample preparation included filtration (0.22 μm), ion exchange clean‐up and FMOC derivatization in the presence of EDTA and borate buffer. The derivatized analytes were extracted with dichloromethane and analyzed by LC-MS/MS.

• UPLC system: ACQUITY UPLC I-Class with FTN Sample Manager and 50 μL loop
• Column: ACQUITY UPLC BEH Phenyl 1.7 μm, 2.1×100 mm
• Mobile phases: 5 mM ammonium acetate pH 9 (A) and methanol (B); flow 0.4 mL/min; gradient 10-100% B in 8 min; run time 16 min
• MS: Xevo TQ-XS with UniSpray; capillary 3.0 kV; desolvation 550 °C; source 150 °C; cone 150 L/h; collision gas 0.14 mL/min
• MRM transitions optimized for FMOC derivatives with isotope-labeled internal standards

Key Results and Discussion

The UniSpray source enhanced ionization efficiency, yielding LLOQs of 0.02 μg/L, well below EU limits. Calibration was linear (0.02–2.0 μg/L) with r2>0.999 and residuals <6%. Recoveries in spiked water ranged from 85% to 110%. Repeatability was <6% RSD. Real sample analysis detected glyphosate at 0.021 μg/L in groundwater, demonstrating method applicability.

Benefits and Practical Applications

This streamlined method eliminates SPE, reduces cost and analysis time, and delivers reliable quantification at trace levels. It is suitable for routine monitoring by water utilities and environmental laboratories to ensure compliance with drinking water and environmental directives.

Future Trends and Opportunities

Further improvements may include expanded internal standard availability (e.g. glufosinate-D3), automation of sample prep, integration with high-throughput workflows, and adaptation to monitor additional polar contaminants. Advances in ionization and data processing will enhance sensitivity and throughput for extensive water quality studies.

Conclusion

The developed FMOC-UPLC-MS/MS method with UniSpray ionization provides a robust, sensitive and efficient approach to the simultaneous determination of glyphosate, AMPA and glufosinate in water matrices. Validation data support its use for regulatory and environmental monitoring.

Reference

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