Direct Analysis of Glyphosate, Glufosinate and AMPA in Beverages Using a Triple Quadrupole LC/MS/MS

Significance of the Topic

The herbicides glyphosate and glufosinate, along with the soil degradation product AMPA, are among the most widely used agricultural chemicals worldwide. Their highly polar nature presents analytical challenges in routine monitoring, especially in complex food and beverage matrices. Ensuring accurate, sensitive, and streamlined methods for detecting these compounds at low levels is essential for food safety, regulatory compliance, and environmental monitoring.

Objectives and Study Overview

This study aimed to develop and validate a direct, high-sensitivity LC-MS/MS method for simultaneous quantification of glyphosate, glufosinate, and AMPA in beverages without complex derivatization or extensive sample cleanup. The focus was on achieving low detection limits, robust calibration, and reliable recovery in real‐world samples such as coffee, tea, wines, and juice.

Methodology and Used Instrumentation

A hydrophilic interaction chromatography (HILIC) approach was employed with the following conditions:

• Liquid chromatograph: Nexera X2 HPLC system
• Column: HILICpak VT-50 2D, 150 × 2.0 mm, 5 μm
• Mobile phases: A = 50 mmol/L ammonium bicarbonate in water; B = acetonitrile
• Gradient: 50 % B for 0–3 min, linear to 5 % B by 7 min, hold to 20 min, then return to 50 % B by 20.01 min
• Flow rate: 0.25 mL/min; column temperature: 40 °C; injection volume: 50 μL

Mass spectrometric detection was performed on an LCMS-8050 triple quadrupole in negative electrospray mode with multiple reaction monitoring (MRM) transitions:

• AMPA: m/z 110 > 78.8, CE = 28 
• Glufosinate: m/z 180.1 > 62.9, CE = 43 
• Glyphosate: m/z 168.1 > 62.9, CE = 24 

Optimal gas flows, temperatures, and use of PEEK tubing at the autosampler reduced adsorption and enhanced sensitivity.

Main Results and Discussion

Calibration curves were established over the range 0.1–10 μg/L, yielding linear responses (r2 > 0.998) for all analytes. Accuracy at each calibration level was between 95.3 and 106.9 %, with area repeatability (RSD) below 9.6 %.

Spike-recovery experiments in five beverage matrices (coffee, tea, red wine, white wine, apple juice) at 100 μg/L (after 100-fold dilution) demonstrated recoveries from 72.9 to 104.9 % and RSD values under 10 %, confirming method robustness in diverse sample types.

Benefits and Practical Applications

The described method eliminates time-consuming derivatization and extensive cleanup, reducing labor and cost. Its simple filtration and dilution workflow allows high sample throughput while maintaining low detection limits and reliable quantification. This approach is directly applicable to quality control labs, environmental monitoring programs, and regulatory testing of beverages and other foodstuffs.

Future Trends and Opportunities

Potential developments include:

• Extension to additional polar pesticide residues and metabolites
• Integration of online sample preparation modules or automated dilutions
• Use of high-resolution mass spectrometry for broader screening
• Adoption of greener solvents and miniaturized HILIC formats
• Application of data analytics and AI for rapid result interpretation and trend prediction

Conclusion

This study presents a streamlined LC-MS/MS protocol for direct analysis of glyphosate, glufosinate, and AMPA in beverages. The method delivers high sensitivity, excellent linearity, and reliable recoveries without complex pretreatment. It offers an efficient solution for routine monitoring and supports safety assurance in the food and environmental sectors.

References

1. Kawashima M. Direct Analysis of Glyphosate, Glufosinate and AMPA in Beverages Using LC-MS/MS. Shimadzu Application Note C181. 2018.