Nitenpyram in tea: Eco-friendly detection methodology and residue behavior.

Area of Science:

• Agricultural Chemistry
• Analytical Chemistry
• Environmental Science

Background:

• Nitenpyram, a neonicotinoid insecticide, is widely used in tea cultivation, but studies on its determination and behavior in tea are limited.
• Existing analytical methods may not be environmentally friendly, prompting the need for an organic-solvent-saving approach.

Purpose of the Study:

• To establish an organic-solvent-saving analytical method for nitenpyram determination in tea.
• To investigate the dissipation kinetics and leaching behavior of nitenpyram in tea.

Main Methods:

• Extraction of nitenpyram using boiling water.
• Cleanup using Cleanert PCX solid-phase extraction.
• Quantification using established analytical techniques.
• Dissipation studies in tea plants under field conditions.
• Leaching studies in made tea using different brewing methods.

Main Results:

• The developed method achieved average recoveries of 75.1-94.5% with low relative standard deviations (0.7-8.6%).
• Significant organic solvent savings (34.5-88.6%) were realized.
• Low limits of quantification (LOQs) were achieved, meeting current minimum Maximum Residue Limits (MRLs).
• Nitenpyram exhibited rapid dissipation in tea plants, with half-lives of 1.2-1.4 days at the recommended dosage.
• A substantial amount of nitenpyram (20-110%) leached from made tea during brewing.

Conclusions:

• The developed analytical method is effective, efficient, and environmentally friendly for nitenpyram detection in tea.
• Nitenpyram dissipates rapidly in tea plants and is significantly removed during the brewing process.
• Findings provide valuable insights for the rational application of nitenpyram in tea cultivation and inform MRL setting.