Polyaniline-dicationic ionic liquid coated with magnetic nanoparticles composite for magnetic solid phase extraction of polycyclic aromatic hydrocarbons in environmental samples

Polyamidoamine dendrimer decorated nanoparticles as an adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol from environmental water samples

Polyamidoamine dendrimer decorated Fe₃O₄ magnetic nanoparticles were successfully synthesized by Michael addition with methyl acrylate and amidation with ethylenediamine. The decorated magnetic particles were utilized as an effective adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol at trace levels from environmental water samples. A number of parameters such as generation number, ionic strength, adsorbent dosage, eluent, adsorption time, elution volume, elution time, pH, humic acid and sample volume were optimized. Under the optimal conditions, a wide linearity was achieved in the range of 0.1-500 μg L^-1 of the analytes with the correlation coefficients (R²) of 0.9985-0.9995. The limits of detection were approximately 0.011 μg L^-1 of tetrabromobisphenol A and 0.017 μg L^-1 of 4-nonylphenol. Satisfactory average recoveries of the analytes ranged from 93.2% to 101.1%. The results indicated that the decorated magnetic nanoparticles can be suitable for extraction of phenols from environmental water samples. The proposed method was sensitive, effective, practical and robust for the determination of tetrabromobisphenol A and 4-nonylphenol in environmental water samples.

Fabrication of calixarene-grafted bio-polymeric magnetic composites for magnetic solid phase extraction of non-steroidal anti-inflammatory drugs in water samples

Calixarene framework functionalized bio-polymeric magnetic composites (MSp-TDI-calix) were synthesized and utilized as magnetic solid-phase extraction (MSPE) sorbent for the extraction of non-steroidal anti-inflammatory drugs (NSAIDs), namely indoprofen (INP), ketoprofen (KTP), ibuprofen (IBP) and fenoprofen (FNP), from environmental water samples. MSp-TDI-calix was characterized by FT-IR, XRD, FESEM, EDX, VSM and BET analysis, and the results were compared with Sp-TDI and Sp-TDI-calix. To maximize the extraction performance of MSp-TDI-calix decisive MSPE affective parameters such as sorbent amount, extraction time, sample volume, type of organic eluent, volume of organic eluent, desorption time and pH were comprehensively optimized prior to HPLC-DAD determination. The analytical validity of the proposed MSPE method was evaluated under optimized conditions and the following figures of merit were acquired: linearity with good determination coefficient (R² ≥ 0.991) over the concentration range of 0.5–500 µg/L, limits of detection (LODs) ranged from 0.06–0.26 µg/L and limits of quantitation (LOQ) between 0.20–0.89 µg/L. Excellent reproducibility and repeatability under harsh environment with inter-day and intra-day relative standard deviations were obtained in the range of 2.5–3.2% and 2.4–3.9% respectively. The proposed method was successfully applied for analysis of NSAIDs in tap water, drinking water and river water with recovery efficiency ranging from 88.1–115.8% with %RSD of 1.6–4.6%.

New sporopollenin-based β-cyclodextrin functionalized magnetic hybrid adsorbent for magnetic solid-phase extraction of nonsteroidal anti-inflammatory drugs from water samples

A magnetic solid-phase extraction (MSPE) procedure on the newly synthesized magnetic β-cyclodextrin functionalized with toluene diisocyanate (TDI) as a linker and further modified with bio-polymeric spores of sporopollenin (MSp-TDI-βCD), was developed for the extraction of nonsteroidal anti-inflammatory drugs (NSAIDs), namely, indoprofen (INP), ketoprofen (KTP), ibuprofen (IBP) and fenoprofen (FNP) from water samples prior to their HPLC-DAD determination. The newly synthesized MSp-TDI-βCD was comprehensibly characterized using FT-IR, XRD, SEM-EDX, BET and VSM analyses. The separation of selected NSAIDs on MSp-TDI-βCD from aqueous solution was simply achieved by applying an external magnetic field via a permanent magnet. The MSPE parameters affecting extraction performance, i.e. sorbent dosage, sample volume, extraction and desorption time, type of organic eluent and volume and solution pH were investigated and optimized. The proposed method showed linear range between 0.5 and 500 ng ml-1, low limit of detection at S/N = 3 (0.16-0.37 ng ml-1) and limit of quantification at S/N = 10 (0.53-1.22 ng ml-1). The inter-day (n = 15) and intra-day (n = 5) precision for the proposed methods given by relative standard deviation (RSD%) was in the range of 2.5-4.0 and 2.1-5.5, respectively. The extraction recoveries of NSAIDs from environmental samples (tap, drinking and river water) ranged from 92.5% to 123.6%, with satisfactory precision (RSD% less than 12.4%).

Magnetic halloysite nanotube/polyaniline/copper composite coupled with gas chromatography-mass spectrometry: A rapid approach for determination of nitro-phenanthrenes in water and soil samples

A fast, sensitive and reliable ultrasound-assisted magnetic dispersive solid-phase microextraction (UAMDSPME) setup was developed and evaluated for the enrichment of nitro- phenanthrenes compound in environmental samples prior to GC-MS determination. A new type of nanocomposite sorbent was made based on halloysite nanotubes (HNTs). HNTs is a type of natural material, have attracted great interest because of their large surface area and high chemical and thermal stability. The hybrid nanocomposite (magnetic HNT@PANI@Cu) was obtained by coating the magnetic HNTs by polyaniline (PANI) and afterwards decorating with metalic copper. Its morphology and surface properties were characterized using Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy dispersive spectroscopy and vibrating sample magnetometry. In this work several factors that may affect the extraction efficiencies such as desorption solvent type and its volume, sonication times for extraction and desorption, sorbent amount, organic modifier content, salt concentration and matrix effect were investigated in detail. Under the optimal conditions, the limit of detection (S/N = 3) was 0.25 ng L^-1 and the linearity was in the range of 0.01-100 μg L^-1. The method precision expressed as relative standard deviations (RSDs%) were 4.6-6.1% (intra-day), and 7.2-9.6% (inter-day). Finally, the presented method was successfully applied to the rapid determination of trace levels of nitro-phenanthrenes in spiked water and soil samples.

Polyaniline modified magnetic nanoparticles coated with dicationic ionic liquid for effective removal of rhodamine B (RB) from aqueous solution

Polyaniline (PANI) modified magnetic nanoparticle (MNP) nanocomposites coated with newly synthesized dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesized as a potential material for the removal of Rhodamine B (RB) from water samples. The synthesized material was successfully characterized using a few techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and transmission electron microscopy (TEM) analysis. Several parameters have been optimized to enhance the efficiency of the removal process. The adsorption kinetics were investigated and the results showed that MNP-PANI-DICAT was best fitted to a pseudo-second order model for the adsorption of RB. As for the isotherm studies, Temkin's model was found to fit well with the adsorption isotherm of RB on MNP-PANI-DICAT. Other than that, thermodynamics results showed negative values of ΔG° for the adsorption of RB, which indicated that the process is thermodynamically feasible, spontaneous and chemically controlled at lower temperature. The negative value of enthalpy ΔH° (−40.41) indicated that the adsorption was an exothermic process. The percentage removal of RB was found to be 94.7% by MNP-PANI-DICAT under optimized conditions.

Schematic diagram of the removal procedure of RB on MNP-PANI-DICAT.