Affiliation:
1. Federal Scientific Center of Hygiene named after F. Erisman, Federal Service for Supervision of Consumer Rights Protection and Human Welfare
Abstract
Introduction. Storage of selected samples before transportation to the laboratory and immediately before analysis is an important component in the process of product quality control and evaluation.
Purpose of the work was to evaluate the degradation of pesticide active substances in real samples of citrus fruit left for long periods of storage in deep freezing conditions.
Materials and methods. High-performance liquid chromatography with triple quadrupole mass detector (HPLC-MS/MS) was used to identify and quantify pesticide active substances. According to the method of analysis MUK 4.1.3657–20, cryogenic grinding of samples was carried out in a cutter using dry ice. Sample preparation was carried out using the QuEChERS technology. To extract analytes from a homogenized sample acetonitrile was used in the presence of salts containing citrate buffer, followed by purification of the extract by SPE.
Results. In the studied samples of citrus, the analytes showed stability. Thirty months after storage of samples in deep freezing conditions (temperature not higher than –20 °C), the identified levels of active ingredients of the pesticides imazalil, pyrimethanil and prochloraz did not change by more than 20% compared to the previously detected concentrations. Insignificant amounts of imidacloprid, thiabendazole and pyriproxyfen, as well as traces of azoxystrobin and trifloxystrobin, detected in the study of samples, were also found in samples after long-term storage.
Limitation. The study is limited to the study of the stability of individual active substances found in real samples of citrus fruits intended for sale to the consumer.
Conclusion. Proper storage of samples should ensure the preservation of the levels of active substances in the samples and exclude their change due to various processes (volatilization, enzymatic and hydrolytic decomposition, etc.), which requires the performance of preliminary experimental studies to assess their stability. The work showed the stability of residual quantities of imazalil, pyrimethanil, prochloraz, imidacloprid, thiabendazole, and pyriproxyfen in citrus fruit matrices under storage conditions in a freezer at not more than –20 °C for 30 months.
Publisher
Federal Scientific Center for Hygiene F.F.Erisman
Subject
Health, Toxicology and Mutagenesis,Public Health, Environmental and Occupational Health,Pollution,General Medicine
Reference23 articles.
1. CAC (Codex Alimentarius Commission). Guidelines on Good Laboratory Practice in Pesticide Residue Analysis; CAC/GL 40-1993, Rev.1-2003.
2. OECD iLibrary. OECD Guidelines for the Testing of Chemicals, Section 5. Test No 506: Stability of Pesticide Residues in Stored Commodities; 2007. Available at: https://doi.org/10.1787/9789264061927-en
3. Analytical quality control and method validation procedures for pesticides residues analysis in food and feed. Supersedes Document №SANTE/11312/2021; 2022. Available at: https://www.eurl-pesticides.eu/userfiles/file/EurlALL/SANTE_11312_2021.pdf
4. FAO. Reports and Evaluations on Pesticide Residues. Available at: https://www.fao.org/pest-and-pesticide-management/guidelines-standards/faowho-joint-meeting-on-pesticide-residues-jmpr/reports/en/
5. Anastassiades M., Lehotay S.J., Stajnbaher D., Schenck F.J. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and “dispersive solid-phase extraction” for the determination of pesticide residues in produce. J. AOAC Int. 2003; 86(2): 412–31.