# The Effect of Ozone on the Behavior of Systemic and Non-Systemic Pesticides in Cereal Grains

## TL;DR

Ozone treatment reduces pesticide residues in cereal grains, with varying effectiveness depending on pesticide type and grain species.

## Contribution

This study is the first to assess ozone's effect on systemic and non-systemic pesticides in cereal grains.

## Key findings

- Ozonation reduced systemic pesticide residues by 37–82% and non-systemic ones by 72–95%.
- Rye showed the highest pesticide degradation rate, followed by wheat and barley.
- Deltamethrin had the highest reduction (95%), while difenoconazole only decreased by 39%.

## Abstract

Cereal grains make up a significant part of both human and animal diets; therefore, they should meet pesticide residue standards and be characterized by the lowest possible concentrations of these residues. Known for its strong oxidizing properties, ozone is gaining popularity as a natural agent for eliminating chemical contaminants at the stages of production, processing, and storage of raw materials of plant origin. The present study is the first to assess the effect of ozonation on the behavior of 12 (seven systemic and five non-systemic) compounds. The procedure was conducted in two time variants (30 and 60 min) for three cereal types: barley, wheat, and rye. Treatment efficiency was confirmed through instrumental determination conducted using the LC–MS/MS technique based on the QuEChERS protocol. The level of systemic compounds was reduced by 37–82%, and of non-systemic ones by approximately 72–95%. The reduction in difenoconazole amounted to only 39%, whereas the highest decrease of 95% was recorded for deltamethrin. The rate of pesticide degradation occurred in the following sequence: rye > wheat > barley. The results show that ozonation of cereal grains may successfully support assurance of food and feed safety.