Inverse dispersive liquid-liquid microextraction(I-DLLME) for the simultaneous and green preconcentration of DEET and permethrin from freshwater

Author(s)

Parente, Camila ; Torgan, Natalia ; Calixto, Leandro Augusto ; Lemos, Sherlan Guimaraes ; Moraes, Maria Lourdes Leite de ; Carrilho, Elma Neide Vasconcelos Martins ; Labuto, Georgia

• Document type: Journal article
• Source: SUSTAINABLE CHEMISTRY AND PHARMACY; v. 27, p. 14-pg., 2022-06-01.

Abstract

Global warming can stimulate mosquitoes to proliferate and the consumption of repellents and insecticides. These formulations can have N,N-diethyl-m-toluamide (DEET) and permethrin, which were reported in water bodies, requiring sensitive methods for quantification. We propose changing the dispersive liquid-liquid microextraction (DLLME), a green extraction technique, by inverting the sequence of injection of the extractant-dispersant solvents to allow better interaction with samples, aiming to improve the reproducibility of analytical results. In the inverse dispersive liquid-liquid microextraction (I-DLLME), samples of deionized water or freshwater enriched with DEET and permethrin isomers (trans = PERM-1) and (cis = PERM-2) were injected over the extractant-dispersant solvents using a micro-syringe. Both DLLME and I-DLLME were optimized using a factorial design and multi-response optimization (desirability function) to establish the condition that provides higher enrichment factor (EF) and reproducibility, denoted by lower relative standard deviations (RSD). Preconcentrated samples were analyzed using a High Performance Liquid Chromatography with Diode Array Detector (HPLC-DAD) method. Under the optimum I-DLLME-HPLC-DAD condition (50 mu L of chloroform as dispersant, 600 mu L of acetonitrile as extractant, 0.007 mol/L of NaCl, and pH = 3), the EF for DEET, PERM-1 and PERM 2 were respectively 67, 170 and 179 with considerable gains in reproducibility (RSDs <= 12%, n = 6). Quantification limits for DEET, PERM-1 and PERM-2 for deionized water and freshwater were respectively 50.0, 4.42 and 2.88 mu g/L, and 33.06, 12.62 and 6.45 mu g/L, without matrix effect. The apparent recovery for freshwater varied between 93% and 103% (RSDs 2.3-12%). The IDLLME-HPLC-DAD method scored 0.61, considering the 12 principles of green analytical chemistry from a unified 0-1 scale. (AU)

• FAPESP's process: 16/06271-4 - Development of adsorbents from yeast biomass residue from industrial fermentation processes to remove emerging contaminants from water and effluents
• Grantee: Geórgia Christina Labuto Araújo
• Support Opportunities: Regular Research Grants