Binary Solvent Dispersive Liquid-Liquid Microextraction for the Determination of Pesticides in Natural Water Samples

Abstract

A binary solvent dispersive liquid-liquid microextraction (BS-DLLME) technique was developed for simultaneous determination of diuron, teflubenzuron, atrazine, and two of its metabolites (desisopropylatrazine and desethylatrazine) in natural waters. The extraction was investigated using a three components mixture design to determine the best ratio between the extractors (dichloromethane and chloroform) and the disperser solvent (acetonitrile). According to the analysis of variance, empirical response surfaces were obtained for each analyte, correlating the absolute recovery and the mixture composition. The analysis of the overlapping surfaces allowed the detection of the best condition for the analytes extraction: 481 µL of chloroform, 56.6 µL of dichloromethane, 906 µL of acetonitrile, 5.00 mL of the aqueous sample, and 10% (m/v) of sodium chloride. The proposed method was validated and successfully applied in the analysis of surface waters, presenting suitable linearity (r > 0.9990), low limits of detection (0.015 to 0.36 µg L -1 ) and quantification (0.049 to 1.2 µg L -1 ), and relative recoveries between 84.8 and 106.1%.

Antropização de microbacia urbanizada dos Rios Santo Antonio e Santa Tereza do Município de Gurupi-TO: Indicadores fitossociológicos

“…Santana et al (2020) empregaram um planejamento de misturas para otimizar a melhor proporção de precursores para a síntese de NADES, pelo mesmo método de síntese por agitação e aquecimento estudado anteriormente, onde os solventes foram preparos sob agitação constante de 220 rpm, a 50 °C por 2 horas. Este planejamento experimental foi empregado para avaliar os efeitos de diferentes composições sob uma ou mais respostas, tendo combinações de misturas de três componentes dispostos em um triângulo, onde suas arestas representam as misturas binárias e os pontos dentro do triângulo as misturas ternárias (ESTEVÃO et al, 2018).…”