MONITORING OF ATRAZINE IN SURFACE WATERS OF AN AGROECOSYSTEM IN THE PROVINCE OF CÓRDOBA (ARGENTINA) USING AN IMMUNOASSAY TECHNIQUE Mariana García 1 , Verónica Lutri 2 , Mónica Blarasín 2 , Edel Matteoda 2 , Susana Bettera 1 , 1 Departamento de Microbiología e Inmunología. Universidad Nacional de Río Cuarto. Ruta Nacional Nº36, Km 601. (5800) Río Cuarto, Argentina 2 Departamento de Geología, Universidad nacional de Río Cuarto. Ruta Nacional Nº36, Km 601. (5800) Río Cuarto, Argentina E-mail: mcgarcia@exa.unrc.edu.ar ABSTRACT Although the use of atrazine has been banned and restricted in several parts of the world, in Argentina this herbicide is still being used. The atrazine detection was made with a fast and relatively cost-effective immunoassay test whose major advantage lied in its ability to quantify with high accuracy both atrazine and its main metabolite, a useful aspect for monitoring and regulatory programs. The atrazine values found in surface water (0.05– 15.6 μg/L) and rainwater (0.23 – 0.73 μg/L) is an undeniable indicator of the impact that agricultural activities generate on the water resource in the Aeolian fluvial plain of Argentina. The major values were detected in the humid periods which also coincides with the herbicide application time. Key Words: atrazine, ELISA, surface waters, pesticides INTRODUCTION Water is of transcendental importance for the humanity’s development since it is a vital resource for people activities and also is an important variable in diverse processes in all ecosystems (Blarasin et al., 2005).The pollution of aquatic ecosystems is directly related to the land uses. In agricultural ecosystems, surface water and the unconfined aquifer can be impacted by the arrival of mobile and/or persistent contaminants from the application of agrochemicals (pesticides and/or fertilizers). Pesticides are substances or a mixture of substances that are intended to control the vectors of human and animal diseases, as well as unwanted species that cause harm or that interfere with agricultural and forestry production (USEPA 2010). Pesticides suffer photo-decomposition, chemical and biological degradation, adsorption- desorption and volatilization processes in the environment. In addition there are various mechanisms by which they can be transferred from one compartment of the environment to another, highlighting the atmospheric processes and all those hydrological phenomena (infiltration, runoff, percolation, etc.) that allow the advective/dispersive/reactive transport of these compounds in surface and groundwater (Lutri et al., 2018). Water is the main diffusing medium of these compounds or their metabolites to other ecosystems where they have harmful effects (Singh and Walker, 2006). With the population growth in recent years and, consequently, the scarcity of farmland and the destruction of crops by pests, the use of pesticides such as atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), herbicide of the s-triazine type, increased significantly and is one of the most common in the world International Journal for Research in Agricultural and Food Science ISSN: 2208-2719 Volume-5 | Issue-4 | April,2019 45