HPLC Determination of Pesticide Residues Widely Employed in Sugar‐Cane Cultures in River Water Samples

Abstract

Pesticides are substances used in agriculture, to increase the quantity and quality of agricultural products. They are toxic, cause environmental contamination, as well as generating public health problems. In the face of their increasing use, the present work aims at the determination of the multi‐residues present in pesticides, which are widely used in sugar cane culture, focusing on the herbicides tebuthiuron; hexazinone; diuron; 2,4‐D; and ametrine in water samples. Liquid–liquid extraction (LLE) and solid phase extraction (SPE), with subsequent analysis by high performance liquid chromatography (HPLC), with ultraviolet detection using acetonitrile/water as mobile phase were used in this study. Two extraction techniques were evaluated, one being solid phase extraction, using C18 as sorbent and acetonitrile as both the solvent to condition the solid phase and for the elution of the analytes; the other technique was liquid–liquid extraction using dichloromethane as the extracting solvent. Both methods presented good recovery values, above 94%. In the analyses of water samples from Ribeirão das Cruzes, Ribeirão das Anhumas, and Córrego do Paiól, none of the studied compounds were registered, neither in the summer nor in the winter seasons.