Pesticides constitute a heterogeneous category of chemicals specifically designed for pests, weeds or plant diseases control. Their application currently remains the most effective and accepted means for plants protection from plague, contributing significantly to enhanced agricultural productivity and crop yields. However, pesticides have been considered potential chemical mutagens. So, its improper use in agriculture has been appointed as a source of risk to human health and to the environment. Considering that water resources are the major destinations of these compounds after application, the aim of this study was to determine the contribution of industrial and agricultural activities to site contamination.  For these, 500 mL of surface water were collected in 12 points.  Arapongas city (north of Paran�, Brazil) has been chosen due to the high rates of cancer, most cases of acute lymphoblastic leukemia (ALL), especially in children. The entire sample was first filtrated in a nylon membrane (0.22 �m) and was divided in 2 flasks (250 mL). The pH was measured and one sample was acidified with 0.1 mol L-1 HCl at pH 2.00, while the other is kept unchanged. The pre-concentration was realized using C18 cartridges (500 mg). The analytes were desorbed from cartridge using 2 mL of methanol, diluted 10 times (100 �L sample + 900 �L water) with ultrapure water. Screening and quantification were performed by LC-MS/MS (Xevo TQ-S). Screening found high contamination of 72 different pesticides from a multiresidue analysis of 401 compounds. Quantification was done only for 6 pesticides (ametryn, atrazine, carbendazym, diuron, imazetapyr and tebuconazole). According to Brazilian law only atrazine had a maximum limit residue (MRL) permitted of 2.00 ppb. However, all samples analyzed presented concentration higher than 5.7 ppb for atrazine, demonstrating an inefficient environmental control in this area and the urgent need to quantify other contaminants, to preserve population health.

Screening and quantification of multiresidue pesticides in surface water

248th National Meeting (2014)

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