Residues of Pesticides and Some Metabolites in Dissolved and Particulate Phase in Surface Stream Water of Cachapoal River Basin, Central Chile

Abstract

48 páginas, 3 tablas y 5 figuras. -- The final version is available at http://www.elsevier.com ; In the last twenty years, pesticide use in Chile has increased more than 160%, generating a greater risk of water resources pollution. The objective of this study was to assess the presence of 22 pesticides and 12 degradation products in surface water samples from the Cachapoal River basin, Central Chile, an area characterized by intense agricultural activity. Pesticide concentrations in the dissolved phase (DP) and particulate phase (PP) in samples collected in the dry season and after precipitation events was assessed. The solid-phase extraction technique was used to preconcentrate the samples and GC/MS and LC/MS were used to detect pesticides. The results present spatio-temporal variations in the proportion and concentration of pesticides and their degradation products in both the DP and PP for each site and sampling period. The most ubiquitous compounds in the dissolved phase were atrazine, atrazine-2-hydroxy (HA), cyprodinil, pyrimethanil, and tebuconazole, while in the particulate phase HA, imidacloprid, diazinon and pyrimidinol were detected. The results presented in this study make up the first record of pesticides in the dissolved and particulate phases in surface water in Chile. They show that the problem of pesticide contamination undoubtedly affects the quality of bodies of water in agricultural areas in Chile and support the need for a proper assessment of the water quality of the Cachapoal River in the future. ; This work was partly funded by the Government of Spain (MINECO/FEDER UE) as part of Project AGL2015-69485-R and National Commission for Scientific and Technological Research, Chile as part of Project CRHIAM/CONICYT/FONDAP/15130015. María José Climent thanks both the National Commission for Scientific and Technological Research (CONICYT N° 21150573) and Water Research Center for Agriculture and Mining for the financing used to carry out this work. ; Peer reviewed