Analysis of Glyphosate and AMPA in Drinking Water with the Agilent 1200 Infinity Series Online SPE Solution

Significance of the Topic

Glyphosate, the most widely used herbicide worldwide, and its main degradation product AMPA have raised environmental and health concerns due to their persistence and prevalence in water sources. Regulatory agencies enforce strict limits for these analytes in drinking water, necessitating sensitive, reliable analytical approaches for routine monitoring and compliance.

Objectives and Overview

This study aimed to develop a rapid, fully automated online SPE–LC–MS/MS method for the determination of glyphosate and AMPA in drinking water. Key goals included achieving low detection limits (<0.01 µg/L), excellent precision and linearity across relevant concentration ranges, and streamlined sample preparation to support high-throughput analysis.

Methodology

Water samples were spiked with glyphosate, AMPA, and isotopically labeled internal standards at levels from 0 to 1,000 ng/L. An offline derivatization with 20 mM FMOC chloride in the presence of EDTA and borate buffer converted the polar compounds into hydrophobic derivatives compatible with reversed-phase separation. Samples were then injected (900 µL) into an online SPE system for automated enrichment and cleanup prior to LC–MS/MS analysis.

Instrument Used

• Agilent 1200 Infinity Series Online SPE Solution coupled to an Agilent 1290 Infinity Flexible Cube
• Agilent 1260 Infinity Binary Pump and Standard Autosampler (900 µL head)
• Agilent 1290 Infinity Thermostat and Flexible Cube with two 2-position/10-port valves
• Agilent ZORBAX Eclipse Plus C18 analytical column (2.1 × 150 mm, 3.5 µm)
• Agilent 6460 Triple Quadrupole LC/MS System with Jet Stream ESI technology

Main Results and Discussion

Chromatographic separation of FMOC-derivatized glyphosate and AMPA yielded retention times of approximately 6.7 min and 7.7 min, respectively. Calibration curves over 100–1,000 ng/L showed outstanding linearity (R² ≈ 0.9997). Precision studies (n = 4) across all levels delivered relative standard deviations below 5 % for peak areas, while retention times exhibited RSDs around 0.11 %. The online SPE approach efficiently removed excess derivatization reagents and buffer components, safeguarding the analytical column and enabling continuous operation.

Benefits and Practical Applications

• Detection limits below regulatory thresholds for drinking water monitoring
• High throughput through automated sample loading, cleanup, and analysis
• Reduced manual handling and improved reproducibility via online SPE integration
• Flexibility to switch between online SPE and direct injection workflows on the same platform

Future Trends and Opportunities

As environmental monitoring demands expand, further miniaturization and multiplexing of online SPE systems can boost sample throughput. Advances in high-resolution mass spectrometry and novel derivatization strategies may enhance selectivity for structurally similar polar pesticides. Integration with digital lab management and AI-driven data analysis will streamline decision making and regulatory reporting.

Conclusion

The Agilent 1200 Infinity Series Online SPE Solution combined with the 1290 Infinity Flexible Cube and 6460 Triple Quadrupole MS provides a robust, sensitive, and fully automated platform for glyphosate and AMPA analysis in drinking water. The method meets stringent regulatory requirements, delivers excellent precision and linearity, and supports high sample throughput with minimal manual intervention.

Reference

• U.S. EPA Technical Factsheet on Glyphosate (2006)
• Richard S., et al. Environmental Health Perspectives 113:716–720 (2005)
• Torstensson L., Borjesson E., Stenström J. Pest Management Science 61:881–886 (2005)
• Directive 2008/105/EC of the European Parliament and Council
• EU Council Directive 98/83/EC on the Quality of Water Intended for Human Consumption
• P. Abrahamsson, Agilent Technologies Publication 5991-3276EN (2013)
• E. Naegele, Agilent Technologies Publication 5991-2140EN (2013)
• B. Schuhn, Agilent Technologies Publication 5991-2405EN (2013)