DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES

The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, linuron, prothiofos, and tebuconazole residues in water samples from the culture and processing of potatoes (Solanum tuberosum L.) was optimized. The complete factorial design and the central rotational compound design combined with the desirability function were used to evaluate and optimize the parameters of the method. The optimized conditions for extracting the pesticides were as follows: 316 µL of toluene, no sodium chloride addition, and a stirring time of 187 s. The method presented an enrichment factor of 142.4 times and good linearity, precision and accuracy, with limits of detection (LOD) of 0.005 - 0.007 mg L^-1 and limits of quantification (LOQ) of 0.016 - 0.022 mg L^-1. The co-extractives of the wastewater samples caused the suppression of the chromatographic response of linuron and prothiofos by 7.82 and 27.63%, respectively. The analyte concentrations in the wastewater samples from the industrial shing process, manual potato washing, and dam water were either lower than the LODs of the method or were absent.

Keywords:
vortex-assisted liquid-liquid microextraction; wastewater; Solanum tuberosum L