Determination of pesticides in the source and drinking waters in Londrina, Paraná, Brazil

Abstract

The Brazilian agricultural model is based on the intensive use of pesticides. Once in the environment, these compounds might target hydric sources, mainly through soil lixiviation or during crop application, exposing water biota as well as humans to contaminants. The objective of this research was identify the presence of 14 pesticides (ametrine, atrazine, azoxystrobin, carbendazim, carbofuran, clomazone, chlorpirifos, diuron, hexazinone, imidacloprid, malathion, simazine, tebuconazole and tebuthiuron) in source water samples and drinking water samples from the city of Londrina, Paraná State, Brazil. 24 water samples were collected biweekly from December 2014 to October 2015. The sample preparation was done using Solid Phase Extraction (SPE) with 3 mL/500 mg C-18 cartridges. Pesticide determination was performed applying Liquid Chromatography tandem Mass Spectrometry (LC-MS/MS). The frequencies of detection of some compounds in source water were: atrazine (85%), azoxystrobin (95%), carbendazim (83%), diuron (75%), imidacloprid (95%), simazine (12%), hexazinone (4%), tebutiuron (4%) and tebuconazole (33%). In the water supply, the following were detected: atrazine (79%), azoxystrobin (95%), carbendazim (8%), diuron (83%), imidacloprid (95%), simazine (12%), hexazinone (4%), tebuthiuron (8%) and tebuconazole (33%). Some of these compounds are included in Brazilian legislation, and in these cases, the concentrations determined in this study varied between 241 and 7 ng L?¹, which were lower than the maximum allowable concentrations for each of the compounds.

Keywords

• Pesticides
• Drinking water
• LC-MS/MS
• Surface water.