Low‐density extraction solvent based solvent‐terminated dispersive liquid–liquid microextraction for quantitative determination of ionizable pesticides in environmental waters

Abstract

A rapid, efficient, and new solvent terminated dispersive liquid-liquid microextraction technique coupled with HPLC was developed for selective extraction and analysis of s-triazine herbicides from environmental water samples. Important parameters influencing the extraction process including type and volume of extraction and disperser solvent, extraction time, sample pH, ionic strength, and extraction temperature were successfully optimized. Under the optimal conditions, there are excellent linear relationships between the analytical results and concentration in the range of 10-400 mg/L for atrazine, propazine, prometryn, and terbutryn. LOD and LOQ ranged from 0.60 to 2.33 μg/L and 2.0 to 7.7 μg/L, respectively. Performance of the analytical technique was evaluated by carrying out the repeatability and reproducibility analyses that were ranged from 2.86 to 5.66% and 4.64 to 5.89% for 100 μg/L of each target analyte, respectively. The proposed method has been successfully applied to the analysis of real water samples and acceptable relative recoveries over the range of 65.93-101.46%, with RSDs ≤ 8.80%, were obtained. The overall results have been compared with the literature values. Thus, the method developed could efficiently be used for selective extraction of the target analytes from complex matrices, particularly environmental waters.

Multi-Residue Method for Determination of Thirty-Five Pesticides, Pharmaceuticals and Personal Care Products in Water Using Ionic Liquid-Dispersive Liquid-Liquid Microextraction Combined with Liquid Chromatography-Tandem Mass Spectrometry

“…A likely explanation for this would be that larger amounts of the extraction solvent decrease the polarity of the aqueous sample due to dissolution of the extraction solvent in the aqueous phase which leads to a decrease in the partition coefficient of analytes which can lead to decreased recoveries. 40 A statistical test was performed to evaluate if there were significant differences between the area values in the volume evaluation of [C 6 MIM][PF 6 ]. There was a significant difference (p < 0.05) in the extraction solvent volume for all compounds.…”

Ultrasound Vortex Assisted Dispersive Liquid-Liquid Microextraction (Usvadllme) Applied to the Determination of the Triazole Flutriafol and Triazines and Triazinones Pesticides in Water

“…Alguns autores também têm destacado a contribuição da estrutura aromática do tolueno na extração de analitos insaturados. [21][22][23] Também foi observado que os analitos com os menores valores de Kow (Tabela 1), ou seja, os mais solúveis em água, foram menos extraídos. …”

“…Resultados semelhantes foram obtidos por Tolcha, Merdassa e Mergessa, 21 que também avaliaram o efeito da força iônica na extração desta classe de agrotóxicos em água por DLLME.…”

Probing trace levels of prometryn solutions: from test samples in the lab toward real samples with tap water

“…This highlights the usefulness of projection techniques not only to handle the data but also to optimize the sensing performance. The performance of SERS-based detection is competitive with a few works in the literature for detection of pesticides in real samples, most of them based on extraction and size exclusion methods in chromatography techniques [8,[34][35][36]. Koeber et al were able to detect triazine herbicides in river samples with a detection limit of 3.3 9 10 -10 mol/L for simazine by combining column size exclusion and adsorption chromatography [31].…”

“…Only a few analytical methods are available that can reach such level of dilution, most of which involve chromatography experiments [7,8]. Electrochemical techniques are also employed in detecting prometryn, although electrochemical sensors based on mercury electrodes [9][10][11] have negative environmental implications.…”