Pesticide residues in surface waters at the headwaters of S?o Louren?o River-MT, Brazil: Validation of a method using solid-phase extraction and liquid chromatography [Resíduos de pesticidas em águas superficiais de área de nascente do rio S?o Louren?o-MT: Valida??o de método por extra??o em fase sólida e cromatografia líquida]

摘要

A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer) as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 μg L ~(-1) were obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of S?o Louren?o river, Mato Grosso, Brazil. Eight pesticides were detected in concentrations ranging from 0.15 to 35.25 μg L~(-1). Considering ecotoxicological data, carbendazim and carbofuran may represent a risk to aquatic organisms. These results draw attention to the contamination of this vulnerable degraded area.