ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Cloud point extraction coupled with ultrasonic-assisted back-extraction for the determination of metalaxyl, fludioxonil and fenarimol in fruits by gas chromatography with flame ionization detection

Iryna S. Makarchuk, Viktoriia O. Klovak, Valentyna M. Levchyk, and Volodymyr O. Doroschuk

Analytical Chemistry Department, Faculty of Chemistry, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine

E-mail: vikaklovak@ukr.net

Received: 28 April 2022  Accepted: 12 August 2022

Abstract:

A new method of cloud point preconcentration coupled with ultrasound-assisted back extraction of fludioxonil, fenarimol, metalaxyl for determination by gas chromatography with flame ionization detection (GC-FID) in fruits was developed. Some parameters with an effect on the extraction, such as the concentration of Triton X-114, pH influence, incubation time, equilibration temperature and centrifuging parameters were studied and optimized. When using solutions of Triton X-114 for extraction of 0.5% (w/v), the complete extraction of fungicides is observed in the pH range 5.2–8.0 under the conditions of the existence of their neutral molecular forms at an equilibrium phase separation temperature of 45 °C. Surfactant-rich phases were formed by centrifuging solutions at 4000 rpm for 15 min. The method was validated and characterized by the following metrological parameters: the limit of detection (LOD, 3σ) of fludioxonil is 0.06 μg⋅mL⁻¹, the limit of quantitation (LOQ, 10σ) – 0.21 μg⋅mL⁻¹, working range 0.21–10.0 μg⋅mL⁻¹; for fenarimol LOD – 0.10 μg⋅mL⁻¹, LOQ – 0.33 μg⋅mL⁻¹, working range – 0.33–10.0 μg⋅mL⁻¹; for metalaxyl LOD – 0.15 μg⋅mL⁻¹, LOQ – 0.50 μg⋅mL⁻¹, working range – 0.50–10.0 μg⋅mL⁻¹. The procedure was used for determination of fludioxonil, fenarimol, metalaxyl in grapes after their treatment with commercial preparations of fungicides. The results show that the sensitivity, metrological characteristics, ecological safety, simplicity and convenience of the suggested procedure exceed its analogs based on extraction using organic solvents.

Graphical abstract

Keywords: Cloud point extraction; Gas chromatography; Simple preparation; Fludioxonil; Fenarimol; Metalaxyl; Non-ionic surfactants

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02431-6

Chemical Papers 76 (12) 7575–7584 (2022)