Abstract In this article, a novel and simple microextraction method, termed ionic liquid/ionic liquid dispersive liquid–liquid microextraction (IL/IL‐DLLME), has been designed and developed for the rapid enrichment and analysis of environmental pollutants. Instead of using hazardous organic solvents, two kinds of ILs, hydrophobic IL and hydrophilic IL, were used as extraction solvent and disperser solvent in IL/IL‐DLLME step, respectively. Permethrin and biphenthrin, two of the often‐used pyrethroid pesticides, were used as model compounds. Factors that may affect the enrichment efficiencies were investigated and optimized in detail. Under optimum conditions, permethrin and biphenthrin exhibited a wide linear relationship over the range 1–100 μg/L. For permethrin and biphenthrin, the precisions were 4.65–7.78%, and limits of detection were found to be 0.28 and 0.83 μg/L, respectively. Satisfactory results were achieved when the present method was applied to analyze the target compounds in real‐world water samples with spiked recoveries over the range 84.1–113.5%. All these facts indicated that IL/IL‐DLLME is a simple and rapid alternative for the enrichment and analysis of environmental pollutants and will have a wide application perspective in the future.
Abstract In this paper, solid‐phase extraction (SPE) in combination with dispersive liquid–liquid microextraction (DLLME) has been developed as a sample pretreatment method with high enrichment factors for the sensitive determination of amide herbicides in water samples. In SPE–DLLME, amide herbicides were adsorbed quantitatively from a large volume of aqueous samples (100 mL) onto a multiwalled carbon nanotube adsorbent (100 mg). After elution of the target compounds from the adsorbent with acetone, the DLLME technique was performed on the resulting solution. Finally, the analytes in the extraction solvent were determined by gas chromatography–mass spectrometry. Some important extraction parameters, such as flow rate of sample, breakthrough volume, sample pH, type and volume of the elution solvent, as well as salt addition, were studied and optimized in detail. Under optimum conditions, high enrichment factors ranging from 6593 to 7873 were achieved in less than 10 min. There was linearity over the range of 0.01–10 μg/L with relative standard deviations of 2.6–8.7%. The limits of detection ranged from 0.002 to 0.006 μg/L. The proposed method was used for the analysis of water samples, and satisfactory results were achieved.
Perfluorinated alkyl substances (PFASs) are persistent, toxic, ubiquitously distributed, and bioaccumulated substances, which have attracted increasing concern. To investigate the environmental effects of PFASs, there is a need to develop a sensitive, rapid, and efficient method for detecting trace level PFASs. In this study, a conjugated microporous polymer (CMP) with loading of fluorine, fabricated by Sonogashira–Hagihara cross-coupling, was exploited as a solid-phase extraction (SPE) adsorbent. The prepared fluorine-functionalized CMP (FCMP), which showed a large surface area of 1089 m 2 ·g −1 , high porosity, and good chemical stability, was used to extract PFASs from water samples. The adsorption mechanism was investigated using a sorption isotherm model, and the main interactions were fluorous and hydrophobic affinity. The FCMP-based SPE combined with high-performance liquid chromatography-tandem mass spectrometry achieved low limits of detection (0.19–0.97 ng·L −1 ), wide linear range (2–1600 ng·L −1 ), and good reproducibility (3.4%–12.9%) under the optimal conditions. Furthermore, the approach was utilized for the analysis of three water samples (snow, river water, and irrigation water) to evaluate its reliability, and satisfactory recovery (70.5%–127.5%) was obtained. Thus, FCMP was feasible SPE adsorbents for the selective extraction of PFASs.
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