Desenvolvimento de métodos analíticos para determinação de resíduos de agrotxicos em alimentos

Abstract

This work was divided into two moments. In the first chapter, the cloud point extraction (CPE) method was used for the extraction and pre-concentration of pesticides 2,4 D, atrazine, malathion, methyl parathion, fipronil, diazinon, deltamethrin and chlorpyrifos in samples of corn and honey. using Triton X 100 and 114 surfactants. The variables pH, surfactant concentration, NaCl concentration and heating time were analyzed in a univariate manner. Limits of detection (LD, S/R = 3) and quantification (LQ) ranged from 0.0005 to 0.0008 mg kg-1 and 0.005 to 0.008 mg kg-1 , respectively, using the CPE process. The validation of the method was carried out from intra-day and inter-day tests, obtaining recovery values ranging from 47.0 to 112.3%. The proposed method was applied to corn and honey samples and the results obtained were promising. In the second chapter, the extraction of the pesticide methyl parathion in honey samples was studied using CPE and electrochemical detection by square wave voltammetry. The variables surfactant concentration, NaCl concentration and heating time were studied using 24 Factor Design and central compound analysis (CCD). The recoveries obtained ranged from 94 to 104% and the limits of detection and quantification were 0.006 μmol L-1 and 0.021 μmol L-1 , respectively.