Integrated ultrasound-assisted magnetic solid-phase extraction for efficient determination and pre-concentration of polycyclic aromatic hydrocarbons from high-consumption soft drinks and non-alcoholic beers in Iran.

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for the extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05%-95.56%) and enrichment factor (90.65-106.38) were obtained at adsorbent mass: 10 mg, adsorption time: 30 min, salt addition: sodium chloride 10% w/v, desorption time: 20 min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 µl. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200 ng/ml with a coefficient of determination > 0.993, the limit of detection = 0.09-0.21 ng/ml, the limit of quantitation = 0.3-0.7 ng/ml, and relative standard deviation < 8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45% with a standard deviation < 6.05%. The proposed method is effective, sensitive, and reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples.

Development and application of metal organic framework/chitosan foams based on ultrasound-assisted solid-phase extraction coupling to UPLC-MS/MS for the determination of five parabens in water.

In this work, a variety of highly porous metal organic framework/chitosan (MOF/CS) foams (MIL-53(Al)/CS, MIL-53(Fe)/CS, MIL-101(Cr)/CS, MIL-101(Fe)/CS, UiO-66(Zr)/CS, and MIL-100(Fe)/CS) were designed and prepared by an ice-templating process. The introduction of MOFs made these foams achieve excellent inherent characters in terms of strength, stability, and adsorption ability. The MOFs incorporated in the foams retained their unique properties. Additionally, the foams were durable and their adsorption abilities had only a little loss after being recycled several times. MIL-53(Al)/CS foam was selected as an adsorbent candidate to develop an ultrasound-assisted solid-phase extraction (UA-SPE) method for the first time, owing to its particularly noteworthy performance among the prepared MOF/CS foams. The method was then successfully applied to extract trace amount of five parabens (methylparaben, ethylparaben, propylparaben, butylparaben, benzylparaben) in water samples, followed by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) detection. Several experimental parameters were investigated. Under the optimal conditions, the linear ranges were 0.5-200 µg/L with regression coefficients (r2) from 0.9948 to 0.9983. The method detection limits were between 0.09 and 0.45 µg/L. The recoveries ranged from 78.75 to 102.1% with relative standard deviations (RSDs) < 7.4%. Furthermore, the molecular interactions and free binding energies between MOFs and parabens were calculated by means of molecular docking to explain the adsorption mechanism deeply. The novel method proposed in this work exhibited many benefits such as easy operation, high enrichment efficiency, less solvent consuming, and higher sensitivity. Such a strategy would expand the application prospect of MOFs in sample pretreatment. Graphical abstract ᅟ.

Cu2O-CuO ball like/multiwalled carbon nanotube hybrid for fast and effective ultrasound-assisted solid phase extraction of uranium at ultra-trace level prior to ICP-MS detection.

Multiwalled carbon nanotube/Cu2O-CuO ball like hybrid material (MWCNTs/Cu2O-CuO) synthesized using of a green hydrothermal process was evaluated as a new sorbent for solid phase extraction of uranium with inductively coupled plasma mass spectrometry (ICP-MS). According to our best knowledge, this new material was synthesized and used as solid phase extraction adsorbent for the first time in the literature. The characterization of new hybrid material was carried out using Raman spectroscopy, X-ray diffraction (XRD) and scanning electronic microscopy techniques (SEM, SEM-EDX and SEM-Mapping). The characterization results demonstrated that the new hybrid nanostructure was successfully obtained. The ultrasound-assisted solid phase extraction (UA-SPE) procedure was performed using 100 mg of new hybrid sorbent, 1000 µL of a 0.1% (w/v) solution of α-benzoin oxime and 2000 µL of phosphate buffer at pH 7.0 for separation and preconcentration of uranium. Uranium was eluted with 2 M HCl and the levels of uranium was measured by using ICP-MS. The linearity was observed between 2.5 and 100 ng mL-1 concentration range with a good correlation coefficient (r = 0.999, n = 7). The obtained limit of detection and quantitation values were 0.52 and 1.70 ng mL-1, respectively. Under optimum conditions, the preconcentration factor (PF) was calculated as 13.3. The accuracy of the developed method was assessed by analyzing of TMDA-62.2, TMDA-70.2 (Environment Canada) and GBW-07423 certified reference water and soil materials. The proposed UA-SPE-ICP-MS procedure developed with MWCNTs/Cu2O-CuO hybrid material was successfully applied to the analysis of uranium at ultra-traces levels in environmental water and geological rock samples.