Nanofluid of zinc oxide nanoparticles in ionic liquid for single drop liquid microextraction of fungicides in environmental waters prior to high performance liquid chromatographic analysis

Abstract

a b s t r a c tUsing a nanofluid obtained by dispersing ZnO nanoparticles (ZnO NPs) in 1-hexyl-3-methylimidazolium hexafluorophosphate, new single drop microextraction method was developed for simultaneous extraction of three fungicides (chlorothalonil, kresoxim-methyl and famoxadone) in water samples prior to their analysis by high performance liquid chromatography (HPLC-VWD). The parameters affecting the extraction efficiency such as amount of ZnO NPs in the nanofluid, solvent volume, extraction time, stirring rate, pH and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.13-0.19 ng/mL, the precision of the method assessed with intra-day and inter-day relative standard deviations were <4.82% and <7.04%, respectively. The proposed method was successfully applied to determine the three fungicides in real water samples including lake water, river water, as well as effluent and influent of wastewater treatment plant, with recoveries in the range of 74.94-96.11% at 5 ng/mL spiking level. Besides to being environmental friendly, the high enrichment factor and the data quality obtained with the proposed method demonstrated its potential for application in multi residue analysis of fungicides in actual water samples.

Ionic liquid-based zinc oxide nanofluid for vortex assisted liquid liquid microextraction of inorganic mercury in environmental waters prior to cold vapor atomic fluorescence spectroscopic detection

“…Dispersing the NPs in the IL enhanced the extraction efficiency which is in line with our recent report [18] and this might be attributed to the higher coefficient of mass transfer due to Brownian motion [20,21,29,30]. The high extraction efficiency at lower ZnO NPs composition may be attributed to saturation of the ILs at higher composition [18,31] which may prevents the extraction of the Hg-APDC complex. Therefore, 0.005% (m/m) ZnO-NF was selected as a proper solvent in the subsequent experiments.…”

“…7). However, at higher which was also observed in our previous work [18]. Therefore, no salt was added in the optimized experiments.…”

“…The two-step method, preparation of the nanoparticles and then dispersion in base fluid, was used in preparation of the nanofluid [18]. In brief, known amount of ZnO NPs, prepared and characterized in our recent report [18] (data not shown here) was dispersed in [HMIM] [PF 6 ], base fluid, and homogeneously distributed and then sonicated for about 90 min to break up any potential clusters of the NPs.…”

“…In brief, known amount of ZnO NPs, prepared and characterized in our recent report [18] (data not shown here) was dispersed in [HMIM] [PF 6 ], base fluid, and homogeneously distributed and then sonicated for about 90 min to break up any potential clusters of the NPs. Nanofluids with various ZnO NPs compositions were prepared and employed as extraction solvent.…”

“…However, avoiding the consumption of toxic solvents, using relatively green reagents, further reducing solvent consumption, minimizing waste generation, extraction time and labor are still of interesting from GAC point of view. Very recently, we reported the use of ionic liquidbased zinc oxide nanofluid (IL-ZnO-NF) as alternative environmentally benign solvent for single drop microextraction of selected fungicides from environmental waters [18]. Nanofluids, obtained from suspension of nanoparticles (size, o100 nm) in base fluids [19], have got great attention in the field of analytical chemistry because of their ability to enhance the mass transfer coefficient in extraction processes [20][21][22].…”