<i>Fusarium</i> Mycotoxins in Maize Field Soils: Method Validation and Implications for Sampling Strategy

Abstract

While mycotoxins are generally regarded as food contamination issues, there is growing interest in mycotoxins as environmental pollutants. The main sources of trichothecene and zearalenone mycotoxins in the environment are mainly attributed to Fusarium infested fields, where mycotoxins can wash off in infested plants or harvest residues. Subsequently, mycotoxins inevitably enter the soil. In this context, investigations into the effects, fate, and transport are still needed. However, there is a lack of analytical methods used to determine Fusarium toxins in soil matrices. We aimed to validate an analytical method capable of determining the toxins nivalenol (NIV), deoxynivalenol (DON), 15-acetyl-deoxynivalenol (15-AcDON), and zearalenone (ZEN), at environmentally relevant concentrations, in five contrasting agricultural soils. Soils were spiked at three levels (3, 9 and 15 ng g−1), extracted by solid-liquid extraction assisted with ultrasonication, using a generic solvent composition of acetonitrile:water 84:16 (v:v) and measured by LC–HRMS. Method validation was successful for NIV, DON, and 15-AcDON with mean recoveries > 93% and RSDr −1 and 0.8 to 2.2 ng g−1 for DON and NIV, respectively. Additionally, we found indication that “hot-spot” concentrations were restricted to small scales (<5 cm) with implications for field scale soil monitoring strategies.

Keywords

• mycotoxins
• <i>Fusarium</i>
• soil
• deoxynivalenol
• nivalenol
• environment