ABSTRACT
There is a great importance of monitoring thiabendazole (TBZ) residues in fruits and vegetables to ensure food safety. Therefore, a new ionic liquid (IL) phase microextraction method using IL, 1-butyl-3-methylimidazoliumhexafluorophosphate [C4mim][PF6], as extracting solvent is proposed for simple and fast determination of low levels of TBZ in fruits and vegetables by spectrophotometry. The method is based on selective complex formation of TBZ with Cu(II) ions in presence of PF6– as counter ion at pH 5.5, and then microextraction of the complex into the fine micro-drops of IL phase. After optimisation of variables affecting microextraction efficiency, the analytical parameters of the method were determined by calibration curves. The method exhibits a linear relationship (0.3–280 μg L−1), low detection limit (0.1 μg L−1), good intra- and inter-day precision (2.4–4.5% as RSDr%, 2.1–5.6% as RSDR%), good recovery (≥95.1–98.2%) and high sensitivity enhancement factor (150) by solvent-based calibration curve. It allows a detection limit of 0.24 μg L−1 and a range of 0.8–250 μg L−1 by the matrix-matched calibration curve. After validation, the method was successfully applied to the determination of TBZ residues with method quantification limits in fruit and vegetables of 2.0 and 2.5 µg kg−1 with and without adding polyvinylpyrrolidone (PVP-15) solution. Recoveries range from 85.5% to 98.2% after spiking (10, 50 and 100 µg kg−1, n: 3).
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Authors have no financial relationship with the organisation that sponsored the research.
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This article does not contain any studies with human or animal subjects.
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On behalf of other authors, informed consent was obtained from all individual participants included in the study.
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