Dissipation study and dietary risk assessment of dinotefuran, DN, and UF in wolfberry

ABSTRACT

In this study, a reliable and efficient residue analytical method to determine dinotefuran and its metabolites [1-methyl-3-(tetrahydro-3-furylmethyl) guanidine (DN) and 1-methyl-3-(tetrahydro-3-furylmethyl) urea (UF)] in wolfberry and soil was established. The mean recoveries from soil and wolfberry matrices ranged from 84.7 to 98.9%, with intra-day relative standard deviations (RSDr) in the range of 0.9–2.5% for three test compounds. The limits of quantification (LOQs) were 0.005 mg kg⁻¹ for dinotefuran, DN, and UF in wolfberry and soil matrices, and the limits of detection (LODs) were 0.0001 mg kg⁻¹ for three compounds in two matrices. The dissipation and residual assay in 2016 with the commercial formulation of dinotefuran • thiamethoxam 30% suspension concentrate (SC) was conducted at four locations of Qinghai, Gansu, Inner Mongolia, and Ningxia province. The dissipation rates of dinotefuran were rapid in wolfberry with the half-lives were 1.4–3.1 days. The dissipation in soil were relatively slow with half-lives 7.5–17.4 days. According to the results of dietary risk assessment, the residue of dinotefuran at the recommended dosage is safe for human

KEYWORDS:

• Wolfberry
• dinotefuran
• dissipation
• final residue
• dietary risk assessment

Disclosure statement

No potential conflict of interest was reported by the authors.

Interest statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the National Key R&D Program of China (No. 2017YFD020030406).