GC-FID determination of acetochlor, metolachlor and alachlor in foods after cloud point extraction

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发表日期：

2026年5月25日

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Tetiana V. Brudko,
Viktoriia O. Klovak,
Valentyna M. Levchyk,
Volodymyr O. Doroschuk

摘要

A new method of cloud point preconcentration coupled with ultrasound-assisted back extraction for the gas chromatography with flame-ionization determination of acetochlor, metolachlor, and alachlor in sprouts and germinated corn kernels was developed. Various parameters affecting the extraction process — such as the concentration of Triton X-114, pH, equilibration temperature, and centrifugation conditions — were investigated and optimized. The influence of key experimental factors on the transfer of pesticides into the surfactant-rich phase was thoroughly studied, including medium acidity, Triton X-114 concentration, incubation time in a water bath, centrifugation settings, and ultrasonic treatment. The highest extraction efficiencies (R > 95%) were achieved under the following conditions: pH 3.0–4.5, Triton X-114 concentration of 0.25% (w/v), and an equilibrium phase separation temperature of 40 °C. The samples were centrifuged at 3000 rpm for 5 min, after which dichloromethane was added for back extraction, followed by ultrasonic treatment for 2 min. The method was validated and characterized by the following metrological parameters: for acetochlor LOD (3σ) − 0.12 μg ml⁻¹ (1.2 μg g⁻¹), LOQ (10σ)− 0.40 μg ml⁻¹ (4.0 μg g⁻¹), working range 0.40–1.60 μg ml⁻¹ (4.0–16.0 μg g⁻¹); for metolachlor LOD (3σ) − 0.09 μg ml⁻¹ (0.9 μg g⁻¹), LOQ (10σ) − 0.30 μg ml⁻¹ (3.0 μg∙g⁻¹), working range − 0.30–1.60 μg ml⁻¹ (3.0–16.0 μg g⁻¹); for alachlor LOD (3σ) − 0.12 μg ml⁻¹ (1.2 μg∙g⁻¹), LOQ (10σ) − 0.36 μg ml⁻¹ (3.6 μg g⁻¹), working range − 0.36–1.60 μg ml⁻¹ (3.6–16.0 μg g⁻¹). The developed procedure was successfully applied to the determination of these pesticides in sprouted corn samples after treatment with commercially available pesticide formulations. The results demonstrate that the proposed approach provides superior sensitivity, improved metrological characteristics, enhanced environmental safety, and greater simplicity compared to conventional solvent-based extraction methods.

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