title: Dispersive liquid-liquid microextraction of silver nanoparticles in water using ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate.
abstract: Using the ionic liquid (IL) 1-octyl-3-methylimidazolium hexafluorophosphate as the extractant and methanol as the dispersion solvent, a dispersive liquid-liquid microextraction method was developed to extract silver nanoparticles (AgNPs) from environmental water samples. Parameters that influenced the extraction efficiency such as IL concentration, pH and extraction time were optimized. Under the optimized conditions, the highest extraction efficiency for AgNPs was above 90% with an enrichment factor of >90. The extracted AgNPs in the IL phase were identified by transmission electron microscopy and ultraviolet-visible spectroscopy, and quantified by inductively coupled plasma mass spectrometry after microwave digestion, with a detection limit of 0.01μg/L. The spiked recovery of AgNPs was 84.4% with a relative standard deviation (RSD) of 3.8% (n=6) at a spiked level of 5μg/L, and 89.7% with a RSD of 2.2% (n=6) at a spiked level of 300μg/L, respectively. Commonly existed environmental ions had a very limited influence on the extraction efficiency. The developed method was successfully applied to the analysis of AgNPs in river water, lake water, and the influent and effluent of a wastewater treatment plant, with recoveries in the range of 71.0%-90.9% at spiking levels of 0.11-4.7μg/L.
authors.affiliation: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China. Electronic address: shachen68@163.com.
authors.forename: Sha
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China; Chemical Metrology and Analytical Science Division, National Institute of Metrology, Beijing 100031, China.
authors.forename: Yuanjing
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Chemical Metrology and Analytical Science Division, National Institute of Metrology, Beijing 100031, China. Electronic address: chaojb@nim.ac.cn.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Chao
authors.affiliation: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Jingfu
authors.initials: J
authors.lastname: Liu
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D060106:Lakes / Q000032:analysis; D059627:Liquid Phase Microextraction; D053768:Metal Nanoparticles / Q000032:analysis*; D045483:Rivers; D012834:Silver / Q000032:analysis*; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; D012834:Silver; D062065:Wastewater; D014874:Water Pollutants, Chemical; C446740:1-octyl-3-methylimidazolium hexafluorophosphate
keywords: 1-Octyl-3-methylimidazolium hexafluorophosphate; Dispersive liquid–liquid microextraction; Ionic liquid; Silver nanoparticle