Pesticides in My Beverage—Screening (and Subsequent Quantification) of Pesticides in Beverages Originating from Leaves, Grapes, Grasses, and the Hydrologic Cycle (Tea, Wine, Milk, and Water) Using Automated SPE

Importance of Topic

Public awareness of pesticide residues in beverages has grown due to potential health effects and strict regulatory limits. Ensuring the safety of tea, wine, milk and drinking water requires reliable analytical methods capable of detecting trace levels of organochlorine, organophosphorus and other pesticide classes. Automated sample preparation helps laboratories meet regulatory guidelines while improving throughput and data quality.

Objectives and Study Overview

This work evaluates the performance of an automated solid-phase extraction (SPE) system for screening and quantification of multiple pesticide residues in aqueous beverages. Key aims include verifying recovery, reproducibility and solvent savings compared to manual liquid-liquid extraction, and demonstrating compatibility with U.S. EPA drinking-water methods (e.g. EPA Methods 508, 8141B, 8081A and others).

Methodology

Samples (tea infusions, wine, milk and water) were pretreated by adding sodium sulfite and acidifying to pH 2. Automated SPE concentrated large sample volumes (up to 20 L) onto C18 cartridges or 47 mm disks. Elution steps used ethyl acetate and dichloromethane; extracts were dried, concentrated to 1 mL and analyzed by gas chromatography with electron-capture detection (GC-ECD) on an Rtx-PCB column.

Used Instrumentation

• Dionex AutoTrace 280 Automated SPE system (1–6 channels)
• 6 mL C18 SPE cartridges and 47 mm C18 Empore™ SPE disks
• Gas chromatograph with electron-capture detector
• Rtx-PCB fused-silica capillary column
• Nitrogen evaporator and analytical balance

Main Results and Discussion

Automated SPE yielded consistent recoveries (typically within 85–115 % at 50 ppb levels) comparable to manual methods. The system handled variable sample volumes with high reproducibility and reduced operator-induced variability. Solvent consumption and hands-on time dropped by over 60 %, addressing common bottlenecks of manual extraction. The closed SPE system minimized exposure to hazardous solvents and eliminated the need for fume-hood operation.

Benefits and Practical Applications

• Compliance with multiple U.S. EPA validated procedures for clean and potable water testing
• Significant reduction of solvent usage and disposal costs
• Unattended operation improves laboratory efficiency and throughput
• Enhanced data quality through reproducible flow control and sample handling

Future Trends and Potential Applications

Expansion to liquid chromatography–mass spectrometry workflows could broaden analyte scope. Miniaturized or online SPE formats may further reduce resource use. Integration with data-driven automation and remote monitoring presents opportunities for smart laboratories and real-time water quality surveillance.

Conclusion

Automated SPE using the AutoTrace 280 platform offers a robust, time- and solvent-saving alternative to manual extraction for pesticide analysis in beverages and water. The approach meets regulatory requirements while delivering high recovery, reproducibility and improved laboratory safety.

Reference

1. Jerschow E. et al. Ann Allergy Asthma Immunol 2012, 109, 420–425.
2. Garcia-Reyes J. et al. Anal Chem 2008, 80, 8966–8974.