A quantitative solid-state Raman spectroscopic method for control of fungicides

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Agrochemical Analysis

Background:

• Fungicide quality control is crucial for agricultural efficacy and safety.
• Accurate quantification of active ingredients and their conformations is essential.
• Existing analytical methods may have limitations in speed or specificity for complex mixtures.

Purpose of the Study:

• To develop and validate a novel analytical procedure for quantifying fungicide mixtures.
• To assess the utility of terahertz-Raman spectroscopy for quality monitoring.
• To compare the new method with established techniques like HPLC-MS and MALDI-MS.

Main Methods:

• Solid-state Raman spectroscopy in the terahertz (THz) region was employed.
• Quantitative analysis of trifloxystrobin (EE, EZ, ZE, ZZ conformations), tebuconazole, and propiconazole mixtures.
• Validation using hybrid High-Performance Liquid Chromatography (HPLC) electrospray ionization (ESI) tandem Mass Spectrometry (MS) and Matrix-Assisted Laser Desorption/Ionization (MALDI) MS.
• Testing on binary mixtures and commercial fungicide formulations (emissive concentrate, water-soluble granules).

Main Results:

• The THz-Raman spectroscopy method demonstrated quantitative accuracy and precision.
• Method validation confirmed its reliability for determining fungicide concentrations.
• Results were corroborated by independent HPLC-MS and MALDI-MS analyses.
• Sufficient sensitivity was achieved, with defined limits of detection (LOD) and quantification (LOQ).

Conclusions:

• THz-Raman spectroscopy offers an effective and sensitive approach for fungicide quality control.
• The developed method is suitable for monitoring commercial fungicide products.
• This technique provides a valuable tool for ensuring product consistency and regulatory compliance.