Dissipation and persistence of thiacloprid in pepper fruits

Sanja Lazic, Dragana Sunjka, Radovan Begovic, Slavica Vukovic
2015 Pesticidi i Fitomedicina  
This study gives insight into the behavior of the neonicotinoid insecticide thiacloprid in greenhouse production of pepper. Thiacloprid was applied at a concentration of 96 g a.i./ ha, as recommended by the manufacturer for aphid control. Degradation of thiacloprid in pepper fruits was evaluated over a ten-day period, starting from the moment of insecticide application. Sample preparation was performed using the QuEChERS method for liquid chromatography with diode array detection for
more » ... tion for identification and quantification of thiacloprid residues in extracts of pepper samples. The method was validated in accordance with the SANCO/12571/2013 document. The obtained mean recovery value was 83.69%, with RSD 5.05%. Intraday precision was 3.21%. Within a concentration range from 0.01-2.0 µg/ml, thiacloprid showed linear calibration with R 2 0.997%, while the quantification limit of the method was 0.01 mg/kg. The results of a field trial showed that thiacloprid dissipated rapidly from 1.136 mg/kg to 0.321 mg/kg with a loss of 72% in the first two days after application. Throughout the experimental period, thiacloprid residues in pepper fruits basically remained at a stable low level, and no residue exceeding 0.198 mg/kg was detected in the terminal residue experiment, which was below the MRL of 1.0 mg/kg. The half-life (DT 50 ) of thiacloprid in pepper fruits obtained in this study was 4.95 days. Finally, the pre-harvest interval (PHI) for thiacloprid prescribed by Serbian authorities was proved to be safe enough in greenhouse production of pepper.
doi:10.2298/pif1504225l fatcat:pa2to3fokzbtbeet4h4l67g4be