A photochemically induced fluorescence based flow-through optosensor for screening of nitenpyram residues in cruciferous vegetables

ABSTRACT

One of the most used agrochemicals in agricultural production, nitenpyram (NTP), has been determined by using a flow-through optosensing device based on Photochemically Induced Fluorescence detection. The combination of both methodologies allows, on one hand, a quick on-line photodegradation of NTP and, on the other hand, the preconcentration, quantification and desorption of the fluorescent photoproduct generated when retained on Sephadex QAE-A25 as solid support, which was monitored at 295 and 362 nm for excitation and emission, respectively. The proposed analytical method presents a detection limit of 500 pg mL⁻¹ by using Multicommutated Flow Injection Analysis. Recovery experiments were carried out in different kinds of cruciferous vegetables at or below the MRL established in Japan, demonstrating that this method combines advantages of simplicity, high sensibility and high selectivity, fulfilling the requirements for its application in quality control. Results obtained in the analysis of real samples were in good agreement with those provided by a reference HPLC method.

GRAPHICAL ABSTRACT

KEYWORDS:

• MCFIA
• nitenpyram
• photo-induced fluorescence
• vegetables
• solid-phase spectroscopy

Acknowledgements

J.J.L. acknowledges research scholarship from the Spanish Government (Ministerio de Educación y Ciencia).

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This study was funded by the Ministerio de Economía y Competitividad [CTQ2016-7511-R].