Pesticide Authentication by Portable FTIR Spectroscopy

Significance of the Topic

Pesticide counterfeiting poses serious threats to agriculture, human health and the environment. Illicit products may lack active ingredients, contain harmful chemicals or be illegally imported. With estimates exceeding one billion dollars in annual global sales of fake pesticides, rapid on-site authentication is critical for protecting crops, consumers and beneficial species.

Objectives and Overview

This study illustrates the use of portable Fourier transform infrared spectroscopy for quick verification of pesticide identity before distribution, blending or field application. It evaluates the capability of Agilent mobile and benchtop FTIR systems to discriminate genuine formulations from dilutions, banned compounds and mislabeled mixtures.

Methodology and Instrumentation

The analysis employed two Agilent FTIR systems equipped with diamond attenuated total reflection sensors. The 4500 model offers full portability and battery operation for true field deployment, while the 5500 bench version supports fixed or van-based laboratories. A commercial pesticide library from ST Japan was used for spectral matching. For each sample, a single drop of pesticide was placed on the ATR crystal. Sixty-four scans at 4 cm-1 resolution were co-added to generate the spectrum. The onboard software conducts automated comparison against reference spectra and issues color-coded alerts for nonconformities.

Main Results and Discussion

The technique successfully identified several chlorinated pesticides subject to international bans or restrictions, including cis- and trans-chlordane, aldrin, lindane and the complex camphechlor mixture. Distinct infrared fingerprints allowed clear differentiation of structurally related isomers. A counterfeit case study demonstrated the rapid detection of a mislabeled herbicide blend containing metsulfuron-methyl instead of the expected compound, preventing crop damage. The system reliably verified active ingredient levels down to approximately five percent in diluted formulations.

Benefits and Practical Applications

• No sample preparation or reagents are needed, enabling results in under one minute.
• Portability allows inspection at points of manufacture, loading docks, storage facilities and border checkpoints.
• Visual alerts and a comprehensive spectral library guide users with minimal training.
• Early interception of off-spec products reduces risks to health, yields and ecosystems.

Future Trends and Opportunities

Enhancements in spectral libraries, including broader compound coverage and machine learning algorithms, will improve detection of novel adulterants. Miniaturization and increased sensitivity may extend quantitation capabilities to lower active ingredient concentrations. Integration with complementary techniques such as portable chromatography or mass spectrometry could offer comprehensive screening for trace residues in crops and environmental samples.

Conclusion

Portable FTIR spectroscopy provides a rapid, reliable and user-friendly tool for pesticide authentication. By enabling on-site verification of product identity and purity, it supports regulatory enforcement, protects agricultural productivity and safeguards public health and the environment.

References

1. Fishel F Global Increase in Counterfeit Pesticides Institute of Food and Agricultural Sciences University of Florida 2009
2. Agilent Technologies Accelerated Analysis of On-Site Pesticide Detection in Vegetables by GC/MSD Publication 5990-8067EN 2011