Validation of a commercial ELISA for the analysis of the insecticide dinotefuran in a variety of analytically challenging vegetables

Abstract

The main objective of this paper was to assess the suitability of an enzyme-linked immunosorbent assay (ELISA) as a rapid and simple screening method for the detection of neonicotinoid insecticide dinotefuran residues in various vegetable samples including carrot, cabbage, green pepper, leek, Japanese mustard spinach (komatsuna), and spinach. Simple dilution of crude sample extracts was effective to circumvent or reduce matrix interference derived from samples. Consequently, ELISA was useful to determine dinotefuran accurately and directly, only requiring methanol extraction and dilution with water. The theoretically estimated limit of detection of dinotefuran for tested samples ranged from 0.06 to 0.12 mg kg⁻¹. The ELISA gave recovery values close to 100% for all samples except komatsuna, which contained lower concentration levels, and the results of the ELISA agreed well with those obtained with conventional HPLC (r > 0.99). Results show that the ELISA evaluated in this study is suitable for the rapid and simple screening method of dinotefuran residue in agricultural samples even without sample pre-treatment.

Keywords:

• immunoassays
• screening – ELISA
• screening – immunoassays
• pesticide residues
• vegetables

Acknowledgements

The authors express their thanks to Mr Takahiro Ara of the National Institute for Agro-Environmental Sciences for providing the incurred agricultural samples.