Development of a Flow Injection Manifold for Napropamide Determination by Photo-Induced Chemiluminescence

Abstract

A new, rapid, and simple method is proposed for the determination of the pesticide napropamide by photo-induced chemiluminescence detection coupled with a flow injection analysis (FIA) system. The emission was obtained by oxidation with periodate in basic medium, of the photoproducts generated on-line by UV irradiation (254 nm) of napropamide in acidic SDS (sodium dodecyl sulfate) medium. The flow method, in combination with the solid phase extraction (SPE) performed off-line with C₁₈ cartridges, allowed the determination of this pesticide over the 0.8–14.0 µ gL⁻¹ range, with a limit of detection of 0.3 µ gL⁻¹. The relative standard deviation (n = 9) at 2.5 µ gL⁻¹ level was 4.3% for the combined FIA-SPE system. After testing the influence of several potential interfering compounds, including ions and other pesticides, the method was successfully applied to the determination of napropamide in spiked water samples with recoveries between 96–103%.

Keywords:

• Chemiluminescence
• Flow injection
• Napropamide
• Pesticides
• Photoreaction

Acknowledgments

This work was supported by the Ministry of Education and Science of Spain (Project CTM2006-11991) and FEDER funds.

Notes

^a Corresponding to 46 s irradiation.

^b Corresponding to 13.7 and 4.6 mL min⁻¹ for carrier and oxidant channels, respectively.

^a Sample was passed through a C₁₈ cartridge.

^a Sample was passed through a C₁₈ cartridge.

^b 8 µg L⁻¹ or 0.2 mg L⁻¹ of napropamide was used with and without SPE, respectively.

MS-RTP: micelle-stabilized room-temperature phosphorescence.

HAI-RTP: heavy-atom-induced room-temperature phosphorescence.

PICL: photoinduced chemiluminescence.

Liq-liq: liquid-liquid extraction.

SPE: solid phase extraction.

CPE: cloud point extraction.