Hydrophobic and aromatic polymer nanofibers for a spin-filter micro solid phase extraction of polycyclic aromatic hydrocarbons in river water

Porphyrin-based magnetic nanocomposites for efficient extraction of polycyclic aromatic hydrocarbons from water samples

The differences in effectiveness of multi-walled carbon nanotubes (MWCNTs) as the dispersive solid-phase extraction (dSPE) sorbent for the selective extraction of polycyclic aromatic hydrocarbons (PAHs) were explained on the basis of theoretical study. It was observed that for low molecular weight PAHs, the recoveries using non-helical and helical MWCNTs were similar. In contrary, for PAHs containing five or more aromatic rings, the extraction efficiency was higher using HMWCNTs than for non-helical ones. Principle component analysis (PCA) as well as providing structural parameters and interaction energies for adsorption processes (PAH + CNT → PAH-CNT) have been used for this purpose. All the PAH + CNT → PAH-CNT adsorption processes considered were found to be thermodynamically favorable. However, the adsorption energies (Eads) for PAHs and the helical carbon nanotube surface estimated for the B(a)P-HCNT and I(1,2,3-cd)P-HCNT are substantially less negative than those observed for PAH molecules interacting with the non-helical CNT. Namely, the Eads calculated in simulated aqueous environment for the B(a)P-MWCNT(6,2) and I(1,2,3-cd)P-MWCNT(6,2) were respectively − 43.32 and − 59.98 kcal/mol, while values of only − 7.75 kcal/mol (B(a)P-HCNT) and − 9.13 kcal/mol (I(1,2,3-cd)P-HCNT) were found for the corresponding PAH-HCNT systems. Therefore, we conclude that the replacement of MWCNTs with HCNTs leads to PAH-HCNT systems in which the interaction energies are much smaller than those estimated for the corresponding PAH-MWCNT systems. HMWCNTs are therefore recommended as the dSPE sorbent phase for the extraction of both low and high molecular weight PAHs from water samples.

A supercritical fluid extraction (SFE) method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) from fresh and fallen pine needles. Toluene-modified CO2 was used as the extracting fluid, and the extracted PAHs were analyzed by GC-MS. Using a two-stage extraction procedure, a static extraction at 180 degrees C and a dynamic extraction at 60 degrees C, and an in-cell silica gel plug plus a post-oven silica gel column, the extraction and fractionation of PAHs can be accomplished in one step. Over a seven month period, a significant variation was observed for PAHs in urban samples, while PAHs in mountain samples were at much lower levels (by a factor of approximately 8) and showed little seasonal change. Although dry fallen needles and fresh needles contained similar amounts of PAHs, in the fallen needles the lower molecular weight PAHs were partially lost while the higher molecular weight PAHs were slightly enriched. Pollution in urban areas was found to be highly localized, and buildings and trees are believed to be important factors in the restriction of atmospheric PAHs.

Naphthyl functionalized magnetic nanoparticles (Fe3O4@SiO2@Nap) was prepared and successfully applied for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from river water samples.

New cold-fiber headspace solid-phase microextraction device for quantitative extraction of polycyclic aromatic hydrocarbons in sediment

Laser-excited Shpol'ski spectrometry has been utilized for the direct determination of polycyclic aromatic hydrocarbons (PAH) in high-temperature extracts of particulate matter. Quantitative data on seven PAH present in two national Bureau of Standards standard reference materials (SRM 1649 and 1650) are reported.

A novel covalent organic framework based magnetic adsorbent was developed for magnetic solid phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs). Covalent organic framework-LZU1 (= Lan Zhou University-1) was covalently immobilized onto polyethyleneimine-functionalized magnetic nanoparticles (COF-LZU1@PEI@Fe3O4), and the resulting material was characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The effects of the pH value of sample solution, percentage of acetonitrile, extraction time and sampling volume on MSPE of six PAHs were investigated. The COF-LZU1@PEI@Fe3O4 displays high extraction efficiency for the PAHs such as pyrene, benzo[a]pyrene, fluoranthene, benz[a]anthracene, benzo[a]fluorathene and dibenz[a,h]anthracene. Following desorption with acetonitrile, the PAHs were quantified by HPLC. The MSPE-HPLC method shows low limit of detection (0.2–20 pg mL−1), wide linear range and good reproducibility (relative standard deviations <4.4% for intra-day and inter-day precision). The method was successfully applied to determine PAHs in environmental samples. Good recoveries were obtained, ranging from 90.9 to 107.8% for water samples and 85.1 to 105.0% for soil samples.

Hydrophobic polymer tethered magnetic zirconium-based metal-organic framework as advance and recyclable adsorbent for microwave-assisted extraction of polycyclic aromatic hydrocarbons from environmental water samples

An organic-inorganic hybrid monolithic column doped with gold nanorods (AuNRs) was prepared and evaluated for solid phase extraction (SPE) of polycyclic aromatic hydrocarbons (PAHs). Excellent dispersibility of AuNRs in binary green porogen system consisting of 1-hexyl-3-methylimidazolium tetrafluoroborate and deep eutectic solvents (DESs) was confirmed by energy dispersive spectrometry (EDS). The particle size of the resulting AuNRs (70-90nm) was thoroughly examined by a transmission electron microscopy (TEM). The redox system including ammonium persulfate (APS) and tetramethylethylenediamine (TEMED) was used to initiate in situ polymerization at 4°C to prepare the hybrid monolith. The mesoporous structure of the AuNR hybrid monoliths was confirmed by scanning electron microscopy (SEM) and nitrogen adsorption. With enrichment factors (EFs) of 150- to 292-fold, the developed method was successfully applied to the determinationof 10 PAHs in wastewater samples. The recoveries at a spiked level were in the range 84.9 to 99.5% with limit of detections (LODs) and relative standard deviations (RSDs) ranging from 0.02 to 0.10μgL-1 and 1.5 to 4.2%, respectively. The correlation coefficients (R2) for the calibration functionobtained were better 0.9991 for the target compounds. Compared tothe AuNR-free monolith, the extraction efficiency of the AuNR-incorporated monolith ismore than two timeshigher. The results indicated that thedoping ofAuNRs is an effective approach to obtain the hybrid monolithic column with good separation ability for PAHs. Graphical abstract.

Environmentally friendly etching of stainless steel wire for plunger-in-needle liquid-phase microextraction of polycyclic aromatic hydrocarbons

Frits coated with nano-structured conducting copolymer for solid-phase extraction of polycyclic aromatic hydrocarbons in water samples and liquid chromatographic analysis.

On-line coupling of immunosorbent and liquid chromatographic analysis for the selective extraction and determination of polycyclic aromatic hydrocarbons in water samples at the ng l −1 level

A new immunoaffinity solid-phase extraction (SPE) methodology based on antigen-antibody interactions was evaluated and optimized for the selective extraction of polycyclic aromatic hydrocarbons (PAHs) in various complex environmental matrices. This immunosorbent (IS) consists of anti-pyrene antibodies immobilized on a silica support and is used as a classical SPE sorbent. The cross-reactivity of the antibodies for analytes structurally related with pyrene allows the simultaneous extraction of the priority PAHs included in the European Union and/or U.S. EPA priority lists. In addition, extraction, trace enrichment, and cleanup are achieved in one step due to the selectivity of the antigen-antibody interaction. For aqueous samples, limitation of unwanted adsorption of the PAHs on vessels or tubing due to their high hydrophobicity is obtained by adding acetonitrile in samples before percolation. Losses due to the volatility of the two- or three-ring PAHs are avoided by coupling on-line the extraction using the anti-pyrene IS with LC. From a sample volume of 80 mL, the sensitivity of the fluorescence associated with the selectivity of the IS allows the quantification of individual PAHs in contaminated or surface water below the 0.02 μg/L level and therefore the fulfillment of the EU regulation for monitoring contaminated surface water used as a source for drinking water. The presence of several PAHs at 0.02 μg/L could be confirmed by spectral identification using the diode array detector. Off-line extraction procedures were also set up for the extraction of PAHs from complex solid environmental matrices such as sludge or mussel extracts. The whole off-line procedure was validated using a sewage sludge reference material containing several PAHs at a concentration varying from 0.5 to 2.2 mg/kg of dry sludge. The high selectivity provided by the antibodies permitted extraction of the PAHs and elimination of the great number of interferents in only one step, so that identification of compounds could be achieved using UV diode array detection.

Fe3O4@ionic liquid@methyl orange nanoparticles as a novel nano-adsorbent for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons in environmental water samples

Spent tea leaves as an adsorbent for micro-solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from water and food samples prior to GC-FID analysis