Abstract
A method of analysis for residues of cyprodinil and fludioxonil in blueberries was developed. Fungicide residues were determined by solid-phase microextraction coupled to GC with nitrogen-phosphorous detection. The effect of pH values and fibre coatings was studied. The solid-phase microextraction fibre coating selected was 100 µm polydimethylsiloxane. The method was selective, with adequate precision and high accuracy and sensitivity. Apparent recoveries ranged within the 99–101% range for cyprodinil and the 98–100% range for fludioxonil; LODs and LOQs were 1.2 and 3.9 µg/kg for cyprodinil and 0.4 and 1.3 µg/kg for fludioxonil, respectively. Statistical parameters indicated a matrix effect; consequently, calibration was performed on spiked samples. Degradation of cyprodinil and fludioxonil was studied in a blueberry field located in Concordia (Argentina), with fruit from Emerald and Jewel varieties. The degradation of these fungicides in both blueberry varieties studied followed first-order rate kinetics for both fungicides, and the half-life for cyprodinil was 2.2 and 3.4 days for Emerald and Jewel cultivars, respectively, and for fludioxonil was 12.7 and 16.3 days, respectively.
Acknowledgements
The authors acknowledge the Agencia Nacional de Promoción Científica y Tecnológica, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, Universidad de Buenos Aires and Universidad de Entre Ríos for financial support.