SAMPLING DEVICES OF PESTICIDES IN SURFACE WATERS BASED ON GLASS FIBER-POLY(ETHYLENE-CO-VINYL ACETATE) ADSORBENTS

Abstract

At present, there is a strong interest in the development of sampling devices for contaminants-in-water with low cost of preparation, easy implementation and allowing the location of a greater number of units per sampling area. In general, these devices are made with resins or polymeric matrices that allow uptake of the compounds of interest, such as poly(ethylene-co-vinyl acetate) (EVA). The objective of this research was to develop and characterize structurally and functionally adsorbents based in fiber glass-EVA (FV-EVA), as well as to evaluate their application in uptake of pesticides in surface waters. To do this, FV-EVA were constructed by solutionevaporation and caracterizaton using different techniques (contact angle, attenuated total reflectance Fourier transform spectroscopy, scanning electron microscopy and test hydraulic permeability). Its adsorption capacity of thirteen pesticides (4 organophosphates and 9 organochlorine) was determined by Gas Chromatography (GC) coupled with Quadrupole Ion-Trap tandem Mass Spectrometry in tandem mode (QIT-MS/MS). The ability to use for sampling under field conditions was assessed by its location in an experimental monitoring in the Rio Cauca (Cali - Colombia). It was evident that the adsorbents obtained correspond to porous adsorbent materials with increased capacity against pesticides greater hydrophobicity. In field studies, the presence of α y β-hexachlorociclohexane, Heptachlore, Clorpirifos, Aldrín, 4,4-DDE (4,4-dichlorediphenyl-ethylene), 4,4-DDD (4,4-dichlorediphenyl-dichloroethane), DDT (dichlorediphenyl-trichlorethane) y Metoxyclore was determined. These compounds have been previously reported in surface water and sediments of studied zone.