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[Display omitted] • Optimized capsule phase microextraction for the determination of PCBs. • Reusable CPME extraction device for PCBs analysis in water samples. • Simple and efficient extraction device in environmental analysis. Due to the adverse effects of polychlorinated biphenyls (PCBs) on human health and ecosystems, their careful monitoring is necessary. In this work, capsule phase microextraction (CPME) combined with gas chromatography-tandem mass spectrometry (GC–MS/MS) was used to extract and determine eight PCBs in water samples. As an extraction device for the CPME procedure, two permeable microporous polypropylene tubes were employed. They contained sol–gel carbowax 20 M (sol–gel CW 20 M) sorbent and a cylindrical magnet. The adsorption and desorption conditions (i.e., type of capsule, sample volume, extraction time, stirring rate, ionic strength, type and volume of eluent, and desorption time) of the microextraction procedure were studied. Under optimum conditions, the extraction was achieved within 20 min using 20 mL of sample at a stirring rate of 1000 rpm, while the elution was performed by immersing the CPME device in 500 μL of acetone for 5 min. Accordingly, the analytical method was validated in terms of linearity, sensitivity, selectivity, enhancement factor, accuracy, and precision, and its greenness and applicability were evaluated. The obtained limits of quantification were equal to 0.010–0.050 μg L−1. The relative recoveries were equal to 91.4 and 110.6 % for intra-day and 88.0–111.2 % for inter-day study, while the relative standard deviation values were better than 10.9 %. Finally, the developed method was used for the analysis of real water samples, proving good fitness-for-purpose. [ABSTRACT FROM AUTHOR]

[Display omitted] • COF-COOH supports the layer of surface molecularly imprinted polymer. • Dummy template in MIP synthesis reduces MET leakage during extraction. • COF-COOH@MIP exhibits fast mass transfer and wide linear range for MET. • COF-COOH@MIP SPE column demonstrates reusability for up to 6 cycles. • HPLC-SPE method with COF-COOH@MIP enables sensitive metamitron analysis in water. Metamitron (MET) is a selective herbicide widely used in agriculture but can persist in the environment and potentially contaminate water resources. This study reports the successful synthesis of a composite adsorbent, COF-COOH@MIP, specifically designed for MET preconcentration via solid-phase extraction (SPE) before high-performance liquid chromatography (HPLC) analysis. COF-COOH@MIP integrates the advantages of covalent organic frameworks (COFs) with their high surface area and stability and molecularly imprinted polymers (MIP) with their tailored recognition cavities. The adsorbent achieved a maximum adsorption capacity of 4.67 μg mg−1. The SPE column packed with COF-COOH@MIP demonstrated excellent reusability, with recovery rates of MET around 100 % after six consecutive cycles. The limit of detection (LOD) and limit of quantification (LOQ) of the established method were remarkably low, at 2.94 ng mL−1 and 9.80 ng mL−1, respectively. The linearity was credible within 0.03-400 μg mL−1 (R2 = 0.9999). The method's applicability to real-world samples was validated by analyzing water from a farm, a ditch, and a river. This method offers a valuable tool for environmental monitoring programs to safeguard water quality from MET pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • SFOD–based air–assisted LLME method for trace pesticide residues was developed. • Extraction and preconcentration of multiclass pesticides was found efficient. • Analysis of pesticides in water samples and soft drinks confirmed reliability. • Determination of multiclass pesticides residues was achieved by HPLC–DAD. • Simple, sensitive and efficient method with high extraction recovery was developed. A fast, simple, efficient and selective surface floating organic droplet–based air–assisted liquid–liquid microextraction method coupled with high performance liquid chromatograph–diode array detector was developed for simultaneous extraction of six multiclass pesticides. The developed method was validated for the extraction, enrichment and quantitative determination of trace level multiclass pesticides from environmental water, mineral water and soft drink samples. The effect of experimental parameters such as type and volume of extraction solvent, addition of salt, solution pH and extraction number were successfully optimized. Under the optimum conditions, the method showed good linearity for all the six multiclass pesticide residues with coefficient of determination within the range of 0.9979–0.9994. The limit of detection and quantification were in the range 0.01 to 0.07 µg L−1 and 0.03 to 0.25 µg L−1, respectively. The reproducibility and repeatability study in terms of %RSD were in the range of 0.88–5.28 and 1.35–6.08, respectively, indicating good precision of the method. The method exhibited acceptable mean relative recovery (%RR) in the range of 71.82 to 110.16 % with %RSDs (n = 3) less than 8 % for all the samples. Thus, the developed method could be utilized as selective extraction and preconcentration of multiclass pesticides from environmental water samples, mineral water and soft drink samples, as well as samples with similar matrices. [ABSTRACT FROM AUTHOR]

Rapid and sensitive detection of hydrogen sulfide (H 2 S) is of great importance for the environmental monitoring. Near-infrared fluorescent probes are recently developed for the sensitive H 2 S detection thanks to their low background interference, while often hampered by relatively long response time (around 30 min). In this work, we reported a fast response (within 5 min), highly sensitive near-infrared (NIR) fluorescent probe (DCM-OCN) for H 2 S. The rapid nucleophilic reaction between cyanate moiety and H 2 S endowed fast response of the NIR probe. The influence of experimental parameters (including CTAB concentration, reaction time, pH value etc.), interference study, and possible mechanism were investigated in detail. The fluorescence increment was linear with H 2 S concentration in 1–10 μM with a detection limit of 0.28 μM (3σ). The probe was successfully applied to environmental water samples including river water, tap water, lake water, mineral water and artificial wastewater. Image 1 • A near-infrared DCM-based fluorescent probe for hydrogen sulfide was reported. • The probe was fast-response, highly sensitive and selective toward H 2 S. • The probe was successfully applied to detect H 2 S in natural waters. [ABSTRACT FROM AUTHOR]

Abstract In this work, for the first time, a revolving solvent bar microextraction (RSBME) system was introduced as an efficient alternative method to conventional SBME. The setup proposed for RSBME provides a stable and repeatable method to increase the preconcentration factor. In order to provide the maximum extraction capacity of the organic acceptor phase, four-hollow fibers were applied. In this setup, an electrical motor driving rotator was employed as mechanical support for the hollow fibers and also to stir the donor phase during extraction time. The applicability of this technique was assessed by preconcentration-determination of ammonia in the environmental water samples. The effective factors on the RSBME efficiency were examined and optimized. Under the optimized RSBME conditions, ammonia was quantified by microcell UV–Vis spectrophotometry, with extensive linearity ranging from 15 to 1000 µg L−1 (R2 = 0.9972), and RSD values less than 3.5%. A preconcentration of 372-fold with the detection limit of 4.5 µg L−1 was achieved. The green character of this technique was evaluated based on the analytical Eco-Scale tool and compared with a reference method. The setup proposed can be applied for the simultaneous extraction of acidic and basic compounds from biological and environmental samples in the near future. Graphical abstract fx1 Highlights • An alternative new method for conventional SBME. • Revolving solvent bar micro-extraction (RSBME) setup with four-hollow fibers geometry. • The extraction system repeatable and stable with high extraction efficiency. • Trace determination of ammonia in the environmental water samples. [ABSTRACT FROM AUTHOR]

• Simultaneous detection of Pb2+ and Cd2+ in water matrix by Fe 3 O 4 @G2-PAD/MCPE was investigated. • Dendritic macromolecule is used as a chelating agent in stripping analysis of heavy metal ions. • The proposed sensor shows well-defined stripping peaks and broad linear ranges. In the present study, second-generation polyamidoamine dendrimer functionalized magnetic nanoparticles (Fe 3 O 4 @G2-PAD) were synthesized and applied for the measuring of Pb2+ and Cd2+ ions in environmental waters. The square wave anodic stripping voltammetry (SWASV) was applied for simultaneous determination of analyte cations after closed-circuit mode. The influence of experimental variables on the performance of the modified magnetic electrode was investigated and optimized. Under optimum conditions, the resulting sensor depicted a linear response to Pb2+ and Cd2+ over a concentration range from 0.5 to 80 ng mL−1. Low detection limits of 0.17 ng mL−1 for Pb2+ and 0.21 ng mL−1 for Cd2+ were obtained following 140 s accumulation time, which are well below than the World Health Organization (WHO) guideline (3 ng mL−1 for cadmium and 10 ng mL−1 for lead) in drinking water. The prepared sensor was successfully applied to the detection of Pb2+ and Cd2+ in the presence of some potentially interfering ions. In addition, the electrochemical sensor was employed for the determination of both heavy metal ions in the real water samples (river water, wastewater and lake water) and the obtained results were satisfactory compared with graphite furnace atomic absorptions spectrometry (GF-AAS) protocol. [ABSTRACT FROM AUTHOR]

Abstract Increasing use of TiO 2 nanoparticles (NPs) leads to an accumulation in environment and a risk to human. In this work, an on-line monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) method was developed for sensitive determination of TiO 2 NPs in environmental water samples. With the presence of citric acid, TiO 2 NPs can be selectively adsorbed on the poly(acrylamide)-vinylpyridine-methylene bis-(acrylamide) (poly(AA-VP-Bis)) monolithic column at pH 1, whereas Ti ions cannot be adsorbed. Factors affecting the extraction efficiency such as sample pH, concentration of citric acid and elution conditions were carefully investigated. Under the optimum conditions, a detection limit of 0.63 μg L−1 for TiO 2 NPs and a sample throughput of 6 h−1 were achieved. The method can be applied to the determination of TiO 2 NPs in the size range of 5–100 nm. The developed method was then applied to the analysis of TiO 2 NPs in the East Lake water and Yangtze River water, and recoveries of 84–109% were obtained for spiked samples. Compared with other reported methods for the determination of metal oxide NPs, the developed on-line monolithic CME-ICP-MS has the merits of simple operation, high throughput and no need for digestion before ICP-MS detection. Graphical abstract fx1 Highlights • An on-line monolithic CME-ICP-MS method was developed for sensitive analysis of TiO 2 NPs in water. • TiO 2 NPs of 5–100 nm can be extracted and distinguished from Ti ions with the presence of citric acid. • The method is simple, high throughput and no digestion required before ICP-MS detection. [ABSTRACT FROM AUTHOR]

Abstract In the present study, the author describe a method for magnetic solid phase extraction (MSPE) combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the quantitation of seven non-steroidal anti-inflammatory drugs (NSAIDs) in environmental water samples. Core-shell Fe 3 O 4 @MIL-100(Fe) as the adsorbent in the MSPE was novelly synthesized and successfully applied for the first time. Several experimental parameters, including the effect of pH value of aqueous solution, the amount of the adsorbent, ionic strength, adsorption time, desorption solvent and its volume, and desorption time, were investigated. Under the optimal conditions, the linear ranges were 0.1–10 µg L−1 for meloxicam, carprofen, indometacin, and tolfenamic acid, 0.2–20 µg L−1 for diclofenac, and 0.3–30 µg L−1 for naproxen and mefenamic acid with the regression coefficients (r) from 0.9987 to 0.9995, respectively. The limits of detection were between 0.02 and 0.09 µg L−1. The method also exhibited excellent precision (RSD ≤ 9.6%), repeatability (RSD ≤ 9.3%), and recovery (75.2–105.2%). The method presented the advantages of simplicity, rapidly, less solvent consumption, and higher sensitivity. It's promising for the core-shell Fe 3 O 4 @MIL-100(Fe) to be used as the adsorbent of MSPE for detecting and removing residues in the environment. Graphical abstract fx1 Highlights • Core-shell magnetic Fe 3 O 4 @MIL-100(Fe) nanoparticles were synthesized by a modified method for the first time. • Core-shell Fe 3 O 4 @MIL-100(Fe) was applied for the efficient enrichment of the trace residual drugs for the first time. • Simplicity, rapidly, less solvent consumption, and higher sensitivity were achieved in the present analytical method. [ABSTRACT FROM AUTHOR]

Abstract A novel method for AuNPs/total Au speciation based on the combination of magnetic solid phase extraction and graphite furnace atomic absorption spectrometry (GFAAS) is described. Ascorbic acid enabled the quantitative extraction of both AuNPs and Au(III) by naked Fe 3 O 4 NPs, whereas a selective extraction of AuNPs was achieved in the presence of sodium thiosulfate. Experimental parameters influencing the extraction of both AuNPs and total Au, namely Fe 3 O 4 NPs mass, L -ascorbic acid concentration, pH, extraction time, sample volume, Na 2 S 2 O 3 concentration and re-dispersion volume of magnetic solid phase prior to introduction in the graphite tube, were evaluated. Under optimal conditions, the proposed method yielded detection limits of 19.5 and 19.7 ng L−1 for AuNPs and Au(III), respectively. Intraday repeatability and inter-day reproducibility were lower than 5.3% (N = 6) and 7.6% (N = 4) for both species, respectively. Enrichment factors over 196, corresponding to extraction efficiencies higher than 98%, were obtained for both species. Remarkably, non-significant differences in the extraction of AuNPs over a wide range of AuNPs sizes and morphologies with different capping agents were observed. The reported method was applied to the analysis of superficial waters, groundwater, seawater and artificial wastewater with good recoveries. The method represents a suitable alternative to other reported methodologies for AuNPs quantification in environmental waters at (ultra)trace levels. Graphical abstract fx1 Highlights • A novel method for AuNPs/Total Au speciation at ultra-trace level was developed. • The method involves the use of naked Fe 3 O 4 NPs in combination with L -ascorbic acid. • Direct analysis of the magnetic solid phase by GFAAS was performed. • No elution or digestion steps were needed. • The method was successfully applied to environmental waters. [ABSTRACT FROM AUTHOR]

Highlights • Synthesis of magnetic β-cyclodextrin-carbon nanotube composite. • Micro solid-phase extraction based on inclusion complex formation. • Extraction of polycyclic aromatic hydrocarbons from environmental water samples. • Good reusability of nanocomposite up to 12 times for the extraction of analytes. Abstract Previous studies have demonstrated the excellent capability of the cyclodextrins in pre-concentration of the organic pollutants from the aqueous solutions. In this work, β-cyclodextrin- multiwalled carbon nano-tube composite was produced from the reaction of oxidized carbon nano-tube with cyclodextrin in the presence of the hydrazine hydrate, and subsequently attaching this composite to the iron oxide nano-particles. Prepared magnetic nano-composite was characterized by the attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), the thermogravimetric analysis (TGA), the field emission scanning electron microscopy (FESEM), and the X-ray diffraction (XRD). This composite was applied to extract seven polycyclic aromatic hydrocarbons (PAHs) from the environmental water samples as follows: naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and benzo[a]pyrene. Analytes analysis was performed using the gas chromatography (GC) followed by the flame ionization detection (FID), and the predominant parameters influencing the extraction efficiency were investigated thoroughly. Under the optimized extraction conditions, the enrichment factor (EF) was ranging from 41.3 to 49.3 (EF max = 50.0), and a suitable linearity was obtained (R2 = 0.992–0.997) within the range of 2.0–1000 ng/mL. The limits of the quantification and detection were 2.0–10.0 and 0.6–3.0 ng/mL, respectively. Finally, the synthesized magnetic sorbent and method were successfully utilized for the analysis of rain, well and agricultural water samples. The relative recoveries were ranging from 75.3–107.0% with an acceptable precision (5.5–8.3%) for PAHs extraction. [ABSTRACT FROM AUTHOR]

In this work, a nanocomposite structured magnetic metal–organic framework named as Fe 3 O 4 @UiO-66-NH 2 was prepared via a simple hydrothermal approach. The as-mentioned nanocomposite was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and the Brunauer–Emmett–Teller (BET) techniques. Using the Fe 3 O 4 @UiO-66-NH 2 as a nanosorbent, an easy and highly effective approach was developed to preconcentrate nine organic UV filters before gas chromatography–mass spectrometry (GC–MS) analysis. Different conditions influencing the extraction efficiency encompassing the sorbent amount, nature and volume of desorption solvent, desorption time, pH of the sample, and extraction time, were examined. Under the optimal experimental parameters, the Fe 3 O 4 @UiO-66-NH 2 -based magnetic solid phase extraction and GC–MS (MSPE–GC–MS) demonstrated linearity in the range of 0.03–1500 ng/L (R2 ≥ 0.9974) and the reproducibility, expressed as RSD, was ≤7.5%. The limits of detection ranged between 0.01 and 0.07 ng/L and limits of quantification were in the range of 0.03–0.4 ng/L. Finally, the suggested approach was satisfactorily utilized to determine nine organic UV filters in different water samples (analytical recoveries between 86.5% and 104.2%). [Display omitted] • Fe 3 O 4 @UiO-66-NH 2 was successfully synthesized via simple hydrothermal approach. • Fe 3 O 4 @UiO-66-NH 2 was used as a MSPE nanosorbent for the enrichment of organic UV filters in environmental water samples. • A new analytical method for the GC–MS detection of 9 organic UV filters in water is provided. • The approach has been proposed and validated demonstrating good analytical features. • The developed method has been effectively applied to analyze various environmental water. [ABSTRACT FROM AUTHOR]

Highlights • The carboxylated magnetic graphene oxide nano-sorbent was synthetized. • The distribution of −COOH and amount on the CMGO surface was determined. • The CMGO-MSPE was developed for the concentration of amine-based organic pollutants. • The CMGO showed good extraction efficiency for sulfonamides from real-world waters. Abstract A magnetic nano-adsorbent material was prepared by functionalizing carboxylic group onto the granule surface of magnetic graphene oxide nanoparticles (CMGO), using in-situ co-precipitating method. The surface morphology was characterized by SEM and TEM. The CMGO was selected as the adsorbent for the magnetic solid phase extraction (MSPE) of sulfonamides (SAs) from environmental water samples, and the eluted analytes were determined by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A series of experimental parameters were optimized to improve the extraction efficiency such as amount of CMGO, extraction time, pH, ionic strength of the sample solution and desorption conditions. When the pH of water sample was 4.00, the extraction recoveries (ERs) for SAs were over 82.0% with 15.0 mg CMGO adsorption for 20 min. Under the optimized extraction conditions, linear range was obtained with coefficients of determination (R2)≥0.9983. The limits of detection for this proposed method were in the range of 0.49–1.59 ng/L, and the enrichment factors were 1320-1702 for eight SAs. The newly developed method was successfully applied to the analysis of trace SAs in real-world water samples, which provided satisfactory ERs in the range of 82.0–106.2% with RSDs less than 7.2%. Overall, it shows a great potential for the concentration of trace amine organic pollutions in complex matrices. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel COF-functionalized composite was prepared via self-assembly method. • The COF@PS-GMA sorbent exhibited great extraction capability for NSAIDs. • Rapid and sensitive method for the determination of NSAIDs was developed. Abstract The growing use of non-steroidal anti-inflammatory drugs (NSAIDs) has seriously affected human health and ecosystems, as a result, the World Health Organization (WHO) has regarded them as emerging contaminants. NSAID’s polar nature and trace amount present in wastewater make their extraction and determination challenging in modern analytical science. Therefore, regarding the need, we herein report a rapid, sensitive and selective in-syringe solid-phase extraction (SPE) method coupled with ultrahigh performance liquid chromatography and UV detector for the determination of seven NSAIDs in environmental water samples. Specifically, the NSAIDs in water samples were directly extracted by using synthesized porous covalent organic framework functionalized poly (styrene-divinyl benzene-glycidylmethacrylate) composite (COF@PS-GMA) without further cleanup procedures. The adsorption of NSAIDs on COF@PS-GMA sorbent was investigated by using adsorption isotherms and kinetic studies. Various parameters, including amount of sorbent, pH of the samples, the volume of desorption solvent, and desorption time that were involved in in-syringe SPE were optimized. Under the optimized conditions, good linearity was observed at 0.005–5.0 μg mL−1 with method quantification limits (LOQs) estimated between 0.54–2.74 μg L−1. The recoveries of the seven NSAIDs at the level of 0.5, 5.0 and 20.0 μg L−1 were ranging from 84.3% to 99.6%. [ABSTRACT FROM AUTHOR]

A novel method for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in environmental water samples was developed using column clean-up (CCU) coupled with continuous flow single drop microextraction (CF-SDME) prior to the determination by gas chromatography-mass spectrometry (GC–MS). In this method, purification, extraction and enrichment were carried out in a single step, which reduced the effect of most organic interferents on the determination of target analytes, greatly simplified the operation process and shortened the whole pre-treatment time. The CCU-CF-SDME system was first used, and shortcomings such as long extraction time, instability of suspended microdrop of the traditional SDME system were overcome. The influences of several experimental parameters, including the type and amount of column packing material, the type and volume of extraction solvent, the flow rate of sample solution, extraction temperature, pH and ionic strength of sample solution, on the extraction efficiency were investigated. Under the optimal experimental conditions, the good linearities were obtained in the concentration range of 0.02–10 μg L −1 with correlation coefficients ranging from 0.9912 to 0.9995 for all the analytes. The limits of detection and quantification of the analytes were in the range of 0.0012–0.0101 μg L −1 and 0.0041–0.0336 μg L −1 , respectively. The pre-concentration factors in the range of 777–978 for the PAHs were obtained. The proposed method was applied on the analysis of environmental water samples, and the recoveries of target analytes were in the range of 81.8–105.8% with the relative standard deviations ranging from 0.5% to 6.4%. The results showed that the developed method was a simple, quick and feasible method for the determination of PAHs in environmental water samples. [ABSTRACT FROM AUTHOR]

In this work, poly(1-vinylimidazole-ethyleneglycol dimethacrylate) (poly(VI-EDMA)) monolith coated stir bars were synthesized by one-pot polymerization, and they exhibited higher extraction efficiency and faster extraction dynamics for selected PFAAs than commercial ethylene glycol modified silicone (EG-silicone) and polydimethylsiloxane (PDMS) coated stir bars. Taking eleven PFAAs as target analytes, including C4-C12 perfluoroalkyl carboxylates (PFCAs) and C6, C8 perfluoroalkane sulfonates (PFSAs), a method combining monolith-based stir bar sorptive extraction (SBSE) with high performance liquid chromatography (HPLC) − electrospray tandem mass spectrometry (ESI–MS/MS) was proposed for the determination of multiplex PFAAs in environmental water samples. Under the optimized conditions, low limits of detection (0.06–0.40 ng/L) and wide linear range (0.6–400 ng/L) were obtained for target PFAAs with. The developed method was then applied for the analysis of target PFAAs in environmental water samples, and recoveries of 80.1–117% and 80.3–122% were obtained for target PFAAs in spiked Yangtze River and East Lake water samples respectively. [ABSTRACT FROM AUTHOR]

In this study, SPE method using a carbon aerogel(CA)-based sorbent was developed and evaluated for the simultaneous extraction of sulfur mustard (HD) degradation products from environmental water samples. Applied CAs proved to be very promising materials for use as SPE sorbents, due to their high porosity, very low density and a large specific surface area. 10 degradation products of HD, both aliphatic and cyclic (thiodiglycol (TDG), TDG sulfoxide, TDG sulfone, 3,5-dithia-1,7-heptanediol, 3,6-dithia-1,8-octanediol, 1,4-thioxane, 1,3-dithiolane, 1,4-dithiane, 1,2,5-trithiepane, and 1,4,5-oxadithiepane) were extracted on a CA-based SPE cartridge. The concentrations of target analytes in the eluate were determined by HPLC-DAD and CE-DAD. Several parameters affecting the extraction efficiency, including the kind and volume of the eluting solvent, sample loading flow rate, volume and ionic strength as well as the reusability of the cartridge, were investigated and optimized to achieve the best performance for the analytes. A series of quantitative parameters such as linear range, coefficient of determination, LOD, LOQ and precision were examined under the optimized conditions. High sensitivity (LODs 0.17–0.50 μM) and high precision (intraday RSD = 2.0–7.7% and interday RSD = 2.7–9.9%) for all the analytes were achieved. The performance of the CA-based sorbent was compared with that of commonly used SPE sorbents. Applied for the analysis of spiked pore water samples collected from the Bornholm Basin, one of the largest chemical warfare dumping sites in the Baltic Sea, the proposed method allowed high SPE recoveries of all the analytes ranging from 83.5 to 99.7% to be obtained. [ABSTRACT FROM AUTHOR]

In this study, the nanometer-sized ferrous-ferric oxide magnetic nanocomposite (Fe 3 O 4 @MnO 2 @Al 2 O 3 @Au) was successfully synthesized using co-precipitation and sol gel methods The structural, morphological and magnetic properties of the nanocomposite material were characterized by FTIR, BET, XRD, SEM/EDS, Zeta-potential measurements, TEM and VSM. The nanocomposite was applied as a sorbent for preconcentration of As via ultrasound assisted magnetic solid phase extraction (UA-MSPE). The preconcentrated arsenic was quantified using ICP-MS. A 2 5−1 fractional factorial design was used as a tool for optimizing the developed analytical methodologies. Under optimized conditions, the limit of detection and quantification were 8.6 and 28.5 ng L −1 respectively. The intraday (n = 15) and interday (n = 5) precisions of the developed UA-MSPE method expressed in terms of relative standard deviation (%RSD) were 4.1 and 6.2% and the enrichment factor was found to be 95. The extraction efficiency of the current method was greater than 95%. The developed UA-MSPE method was successfully applied in the preconcentration of arsenic in environmental water samples and nanocomposites modified with MnO 2 , Al 2 O 3 , Au and their application for preconcentration of arsenic in river water sample and the concentration ranged from 0.13–0.18 μg L −1 . The Fe 3 O 4 @MnO 2 @Al 2 O 3 @Au nanoadsorbent combined the advantages of magnetic separability and high affinity toward arsenic adsorption. [ABSTRACT FROM AUTHOR]

In this work, a novel kind of magnetic, core-shell structured and surface molecularly imprinted polymers (MMIPs) for the recognition of salicylic acid (SA) was facilely synthesized through a surface imprinting and sol-gel polymerization approach. The as-synthesized MMIPs exhibit uniform core-shell structure and favorable magnetic properties with a saturation magnetization of 22.8 emu g −1 . The binding experiments demonstrated that MMIPs possessed high binding and specific recognition capacity, as well as fast binding kinetics and phase separation rate. The maximum binding capacity of MMIPs is around 36.8 mg g −1 , nearly 6 times that of the magnetic non-imprinted polymers (MNIPs). Moreover, the selectivity experiments show that all the relative selectivity coefficients towards SA over its structure analogs are higher than 18, further indicating the markedly enhanced binding selectivity of MMIPs. Furthermore, the MMIPs were successfully applied for the determination of SA in environmental water samples with the recovery rates ranging from 94.0 to 108.0 %. This strategy may provide a versatile approach for the fabrication of well-defined molecularly imprinted polymers on nanomaterials for the analysis of complicated matrixes. [ABSTRACT FROM AUTHOR]

Stable and reusable porphyrin-based magnetic nanocomposites were successfully synthesized for efficient extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. Meso-Tetra (4-carboxyphenyl) porphyrin (TCPP), a kind of porphyrin, can connect the copolymer after amidation and was linked to Fe 3 O 4 @SiO 2 magnetic nanospheres via cross-coupling. Several characteristic techniques such as field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, vibrating sample magnetometry and a tensiometer were used to characterize the as-synthesized materials. The structure of the copolymer was similar to that of graphene, possessing sp 2 -conjugated carbon rings, but with an appropriate amount of delocalized π-electrons giving rise to the higher extraction efficiency for heavy PAHs without sacrificing the performance in the extraction of light PAHs. Six extraction parameters, including the TCPP:Fe 3 O 4 @SiO 2 (m:m) ratio, the amount of adsorbents, the type of desorption solvent, the desorption solvent volume, the adsorption time and the desorption time, were investigated. After the optimization of extraction conditions, a comparison of the extraction efficiency of Fe 3 O 4 @SiO 2 -TCPP and Fe 3 O 4 @SiO 2 @GO was carried out. The adsorption mechanism of TCPP to PAHs was studied by first-principles density functional theory (DFT) calculations. Combining experimental and calculated results, it was shown that the π-π stacking interaction was the main adsorption mechanism of TCPP for PAHs and that the amount of delocalized π-electrons plays an important role in the elution process. Under the optimal conditions, Fe 3 O 4 @SiO 2 -porphyrin showed good precision in intra-day (<8.9%) and inter-day (<13.0%) detection, low method detection limits (2–10 ng L −1 ), and wide linearity (10–10000 ng L −1 ). The method was applied to simultaneous analysis of 15 PAHs with acceptable recoveries, which were 71.1%-106.0% for ground water samples and 73.7%–107.1% for Yangtze River water samples, respectively. [ABSTRACT FROM AUTHOR]

Salbutamol (SAL) has potential hazardous effects on health, and has been found in natural water globally. To protect consumers from risks related to SAL residues, a fast and highly sensitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of SAL in environmental water samples. SAL hapten was synthesized and conjugated to proteins to be used as the immunogen for producing polyclonal antibodies. Under optimized conditions, the ELISA showed a 50% inhibitory concentration (IC 50 value) of 0.466 μg/L, with a limit of detection (LOD, IC 10 value) of 0.021 μg/L. The LOD of the ELISA was 5-fold lower than the maximum residue limits. The average recoveries of SAL from environmental samples, including tap water, river water and wastewater, ranged from 80.1 to 115.6%, which is well within the requirements of residue detection. Moreover, the results of the ELISA correlated well with high-performance liquid chromatography results, with a correlation coefficient of 0.988. These results suggest that the proposed ELISA method has potential application for the monitoring of SAL residues in environmental water samples. [ABSTRACT FROM AUTHOR]

A mesoporous silica Santa Barbara Amorphous-15 (SBA-15) has been first functionalized with 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (a silane with three amines) and then reacted with an excess of phenyl glycidyl ether to generate a mixed-mode anion-exchanger containing both anion-exchange (three amines) and reversed-phase (multiple ether-linked phenyls) functionalities in a single branched ligand. The resulting material has been characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, Fourier-transform infrared spectroscopy, and elemental analysis. The results obtained indicated a BET specific surface area (S BET ) of 362.5 m 2 g −1 , a pore volume of 0.70 cm 3 g −1 with a narrow pore size distribution centered at 6.6 nm, and carbon and nitrogen contents of 28.30% and 2.84%, respectively. The dimensions of these particles (∼5 μm diameter, ∼60 μm length), their large surface areas, their high-density functionalities and anion-exchange mixed-mode characteristics make them very attractive for highly effective solid phase extraction (SPE) of acidic nonsteroidal anti-inflammatory drugs (NSAIDs). The important parameters on extraction efficiency including sample pH, breakthrough volume, type and volume of eluent were optimized. A simple and sensitive analytical method based on mixed-mode SPE coupled to high-performance liquid chromatography with ultraviolet detection (HPLC-UV) was developed and successfully applied to the analysis of four NSAIDs (ketoprofen, naproxen, diclofenac, and ibuprofen) in spiked real water samples with satisfactory recoveries (80.6–110.9%) and repeatability (relative standard deviation <11.3%, n = 3). The limit of detections of four NSAIDs were 0.006–0.070 μg L −1 for tap water, and 0.014–0.16 μg L −1 for river water and wastewater, with the enrichment factors of 806–1109-fold. [ABSTRACT FROM AUTHOR]

The crystal phase influences the electrochemical activity of electrode materials. In particular, mixed phases contain metal ions with different oxidation states which enable conductivity and enhance the electrochemical activity. Moreover, 2D nanomaterials enhance the adsorption of target molecules owing to their surface properties. Based on that, the nanocomposite of mixed spinel metal oxide [Co, Mn oxides (CMO NPs)]/and functionalized boron nitride (f-BN) was prepared first time for the electrochemical sensor applications towards herbicide diuron determination. The CMO NPs/f-BN composite has been confirmed by various spectroscopic and microscopic analyses such as p-XRD, FT-IR, FE-SEM, and HR-TEM techniques. p-XRD and FTIR analysis proved the formation of mixed spinel of Co, Mn oxides. Interestingly, morphological investigations revealed that CMO NPs formed as an irregular cubic shape with ± 120 nm in size and f-BN existed in lateral flake-like morphology. FT-IR exhibits, that functionalization promotes the transmittance of functional groups (-OH) of h-BN. The CMO NPs/f-BN/GCE exhibits the well-resolved DU oxidation peak in the CV experiments, owing to the synergetic effect between the CMO NPs and well-functionalized f-BN. In addition, CMO NPs/f-BN/GCE exhibits a low detection limit of 13 nM along with a sensitivity of 0.323 μA µM−1 cm−2 between the two linear ranges of 0.01–419 µM and 569–1770 µM. The proposed sensor showed good repeatability, reproducibility, and stability in DPV analysis. The fabricated DU sensor was successfully applied to real sample analysis in environmental water samples with acceptable recovery results, suggesting CMO NPs/f-BN composite as a beneficial electrode material for the determination of DU. [Display omitted] [ABSTRACT FROM AUTHOR]

Synthetic cathinones have become popular in recent years, which would explain why their determination in influent sewage samples has already been documented. In the present study a method based on solid-phase extraction followed by liquid chromatography and high resolution mass spectrometry is developed, validated and applied to determine twelve cathinones and one of their metabolites in different environmental samples including influent and effluent sewage and river water. Two cation-exchange sorbents (Oasis MCX and Oasis WCX) were compared, with better results achieved with Oasis WCX in terms of apparent recoveries (70–100%) and matrix effects (lower than −34%). The method was validated with effluent sewage samples providing suitable figures of merit, with method quantification limits ranging from 1 ng/L to 5 ng/L and method detection limits from 0.1 ng/L to 0.5 ng/L for all the compounds. Of the different cathinones studied, three, namely methylone, mephedrone metabolite and methylenedioxypyrovalerone, were quantified at concentration levels of low ng/L in each of the different samples analysed, while a number of the other cathinones were also detected in some of the samples. [ABSTRACT FROM AUTHOR]

Technetium-99 ( 99 Tc) determination at trace level by inductively coupled plasma mass spectrometry (ICP-MS) is challenging because there is no readily available appropriate Tc isotopic tracer. A new method using Re as a recovery tracer to determine 99 Tc in fresh water samples, which does not require any evaporation step, was developed. Tc(VII) and Re(VII) were pre-concentrated on a small anion exchange resin (AER) cartridge from one litre of water sample. They were then efficiently eluted from the AER using a potassium permanganate (KMnO 4 ) solution. After the reduction of KMnO 4 in 2 M sulfuric acid solution, the sample was passed through a small TRU resin cartridge. Tc(VII) and Re(VII) retained on the TRU resin were eluted using near boiling water, which can be directly used for the ICP-MS measurement. The results for method optimisation, validation and application were reported. [ABSTRACT FROM AUTHOR]

A rapid, accurate and sensitive method, using the stable isotope labeling (SIL), microwave-assisted dispersive liquid-liquid micro extraction (MADLLME) and the ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), was developed and validated for the determination of hydroxyl UV Filters in environmental water samples. A pair of new isotopic tags D 0 -/D 3 -1-methylindole-3-acetic acid (D 0 -/D 3 -MIAA) is synthesized, with which a simple yet efficient pretreatment MADLLME-SIL is developed. Under the optimized conditions (80 ℃, 240 W, 180 s), the sample pretreatment including analyte extraction, pre-concentration and isotope labeling can be finished conveniently in only 9 min. D 0 -/D 3 -MIAA labeling improves the chromatographic retention by strengthening the hydrophobicity and enhances the MS response for 3–4 orders of magnitude. Excellent linearity is established by the H/D ratios of 1/10–10/1 with the correlation coefficients >0.9990. The quite low detection limits (0.54–1.79 ng/L) are achieved, ensuring the trace detection. This method is successfully applied to a series of environmental water samples. The recoveries (93.2%~103.5%) are significantly improved and the analysis time is largely reduced (<15 min). The excellent sensitivity, accuracy, recovery, and efficiency demonstrate this MADLLME-SIL-LC-MS/MS method a superior alternative for the analysis of UV filters in water samples. [ABSTRACT FROM AUTHOR]

In this study, covalent triazine framework-1 (CTF-1) was adopted as solid phase extraction (SPE) sorbents, and a method of SPE inline coupled with high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for trace analysis of three nitroimidazolaes (including metronidazole, ronidazole and dimetridazole) in porcine liver and environmental water samples. CTF-1 has rich π-electron and N containing triazine, thus can form π–π interaction and intermolecular hydrogen bond with three target polar nitroimidazoles, resulting in high extraction efficiency (87%–98%). Besides, CTF-1 has large specific area, which benefits rapid mass transfer and low column pressure, leading to fast adsorption/desorption dynamics. Several parameters affecting inline SPE including pH, sample flow rate, sample volume, desorption reagents, elution flow rate, elution volume, and ionic strength were investigated. Under the optimal experimental conditions, the limits of detection (S/N = 3) were found to be in the range of 0.11-0.13 μg/L. The enrichment factors (EFs) ranged from 52 to 59 fold (theoretical EF was 60-fold). The relative standard deviations were in the range of 4.3–9.4% (n = 7, c = 1 μg/L), and the linear range was 0.5–500 μg/L for three target analytes. The sample throughput is 7/h. The proposed method was successfully applied to the analysis of nitroimidazoles in porcine liver and environmental water samples with good recoveries for the spiked samples. [ABSTRACT FROM AUTHOR]

A novel dual-emission ratiometric fluorescent sensor Eu3+/CDs@UiO-66 was synthesized by post-synthesis modifying of UiO-66, a zirconium-based MOF formed by 1,4-phthalic acid (PTA) and Zr4+ , with europium ion (Eu3+) and carbon dots (CDs) and utilized for the determination of Cu2+ ions. The prepared composites not only maintain the excellent optical properties of CDs and Eu3+ but also have good stability in an aqueous solution. At the excitation wavelength of 299 nm, Eu3+/CDs@UiO-66 has two distinct emission peaks at 394 nm and 615 nm, respectively. More interestingly, when the material was dispersed in an aqueous solution containing Cu2+ ions, the characteristic peak of Eu3+ at 615 nm decreased significantly, while the characteristic peak of CDs at 394 nm remained unchanged. In the range of 0–500 μM, the relative fluorescence intensity ratio (F 394 /F 615) linearly increased with increasing Cu2+ ion concentration, and the detection limit was calculated to be 51 nM (3S b /K sv). At the same time, the material can also be effectively applied to the detection of Cu2+ in environmental water samples. So Eu3+/CDs@UiO-66 can be developed as a potential ratiometric fluorescent sensor to detect Cu2+ ions. [Display omitted] • A novel dual-emission ratiometric fluorescent sensor is fabricated for Cu2+ sensing • CDs is prepared with environmentally friendly Pinellia pinellia as raw material. • This method is beneficial for copper visual analysis. [ABSTRACT FROM AUTHOR]

A novel sorbent material employing magnetic nanoparticles (MNPs) coupled to graphene oxide (GO) functionalized with 4-aminobenzenesulfonic acid (M@GO-ABS) has been synthesized and applied to develop an inexpensive and automatic method for Cr(III) and Cr(VI) speciation in environmental samples; the developed method combines inductively coupled plasma optical emission spectrometry (ICP-OES) with on-line magnetic solid phase extraction (MSPE). Two magnetic-knotted reactors containing M@GO-ABS were installed in the eight-port injection valve of a flow injection (FI) manifold. Two different eluents were used, one for Cr(VI) (the most toxic chromium species) and one for total Cr concentration. Cr(III) concentration was calculated by the difference between Cr(VI) concentration and total Cr concentration. The optimized method presented detection limits (LOD, peak height) of 0.1 μg L−1 for chromium (VI) and 0.08 μg L−1 for total chromium, and enrichment factors of 15 and 23, respectively. Certified reference materials (TMDA 54.5 fortified lake water and SPS-SW2 surface water) and spiked aqueous samples were used to validate the developed method. The developed method was fruitfully applied to chromium speciation in environmental water samples such as seawater, well water and tap water collected in Málaga (Spain). The obtained values were in good agreement with the certified values, and the recoveries were found in the range of 91–108% for the spiked samples. [Display omitted] • A new magnetic chelating sorbent has been designed for chromium speciation and determination. • The M@GO-ABS system was optimized by two central composite designs (CCD). • The M@GO-ABS allows the preconcentration of Chromium(VI) and total Chromium in enviromental waters. • The method offers simplicity, accuracy, reproducibility and low cost. • The system can be applied in saline water, such as seawater samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dispersive micro solid-phase extraction was developed for extracting paclitaxel and vinorelbine. • MIL-88B@MIL-88A@chitosan was synthesized as a green DµSPE sorbent. • The percentage of three sorbent components was optimized using an optimal mixture design. • Effective factors in the DµSPE were optimized with a Plackett-Burman design and a Box-Behnken design. • Real water and urine samples were analyzed to determine the anti-cancers with the procedure. Dispersive micro solid phase extraction based on a novel and green sorbent was introduced to extract two anti-cancers (paclitaxel and vinorelbine) from environmental water and urine samples. The new composite containing chitosan, MIL-88B and MIL-88A was synthesized as a green sorbent using hydrothermal and chemical procedures. For this purpose, a MOF-on-MOF was prepared based on growing MIL-88B on MIL-88A as a sorbent core. Then, MIL-88B@MIL-88A was coated with chitosan to prepare the sorbent (MIL-88B@MIL-88A@chitosan). The sorbent's ability to extract paclitaxel and vinorelbine was compared with the sorbent components, indicating that coating MIL-88B@MIL-88A with chitosan leads to a significant increase in the analytes' recoveries. A Plackett-Burman design and a Box-Behnken design were utilized for screening the factors and optimizing the significant factors in the microextraction procedure, respectively. The method exhibits a linear range between 0.11 and 217.4 and 0.12–234.8 ng mL−1 with R2 higher than 0.9931 for determining paclitaxel and vinorelbine, respectively. The limit of detection for the measurement of paclitaxel and vinorelbine were 0.03 ng mL−1. The intra-day and inter-day RSDs were in the range of 3.1–3.8 % and 3.7–4.2 % for triplicate determination of paclitaxel and vinorelbine, respectively. Besides, the method was utilized to analyze river water, well water, and two urine samples. The relative recoveries of paclitaxel and vinorelbine for analyzing these real water samples were in the ranges of 88–97.6 % and 90.0–97.8 %, with relative standard deviations between 3.7 and 6.7 %, respectively. [ABSTRACT FROM AUTHOR]

A paper-based polymeric ionic liquid (p-Poly-(MMA-IL)) was successfully developed by grafting the polymeric ionic liquid on the surface of commercial filter paper (FP) by using the dipping method, presenting a new cost-effective film. The newly developed p-Poly-(MMA-IL) FP was then applied as a paper-based thin-film microextraction (p-TFME) analytical device to extract 14 compounds as representative of five groups of antibiotic drugs, which were sulfonamides, tetracyclines, fluoroquinolones, penicillin and macrolides in environmental water samples. Besides, p-Poly-(MMA-IL) FP, p-Poly-(MMA) FP, and unmodified filter paper were successfully characterised by FTIR, NMR, FESEM, TGA, and XRD techniques. They underwent significant parameters optimisation, which affected the extraction efficiency. Under optimal conditions, the proposed (p-Poly-(MMA-IL) FP-TFME) device method was evaluated and applied to analyse multi-class antibiotic drugs in environmental water samples by using a liquid chromatography-mass spectrometry (LC-MS). The validation method showed that a good linearity (0.1 μg L−1 - 500 μg L−1) was noted (R2 > 0.993, n = 3). Detection and quantification limits were within 0.05 μg L−1 – 4.52 μg L−1 and 0.15 μg L−1 – 13.6 μg L−1, respectively. The relative standard deviation (RSD) values ranged at 1.4%–12.2% (intra-day, n = 15) and 4.4%–11.0% (inter-day, n = 10). The extraction recoveries of environmental water samples ranged from 79.1% to 126.8%, with an RSD of less than 15.4% (n = 3). The newly developed paper-based polymeric ionic liquid (p-Poly-(MMA-IL) FP) for analysis of multi-class antibiotic drugs under the p-TFME analytical device procedure was successfully achieved with limited sample volume and organic solvent, fast extraction, and feasible in daily analysis. The detection concentration and relative RSD of multi-class antibiotics determined in various environmental water samples by the proposed method (n = 5) were within 0.44 μg L−1 – 54.41 μg L−1 and 0.69%–15.56%, respectively. These results signified the potential of the p-Poly-(MMA-IL) FP-TFME device as an efficient, sensitive and environmentally friendly approach for analysing antibiotics. Schematic illustration of p-Poly-(MMA-IL) FP-TFME analytical device procedure for multi-class antibiotic drugs analysis. [Display omitted] • New promising paper-based polymer ionic liquid adsorbent for multi-class of antibiotic drugs analysis. • The sample preparation of the p-TFME analytical device method compliance with green analytical chemistry. • Extraction of multi-class antibiotics in the environmental water samples prior to liquid chromatography-mass spectrometry. [ABSTRACT FROM AUTHOR]

A rapid, sensitive and accurate method for the simultaneous extraction and determination of five types of trace phthalate esters (PAEs) in environmental water and beverage samples using magnetic molecularly imprinted solid-phase extraction (MMIP–SPE) coupled with gas chromatography–mass spectrometry (GC–MS) was developed. A novel type of molecularly imprinted polymers on the surface of yolk-shell magnetic mesoporous carbon (Fe 3 O 4 @void@C–MIPs) was used as an efficient adsorbent for selective adsorption of phthalate esters based on magnetic solid–phase extraction (MSPE). The real samples were first preconcentrated by Fe 3 O 4 @void@C–MIPs, subsequently extracted by eluent and finally determined by GC–MS after magnetic separation. Several variables affecting the extraction efficiency of the analytes, including the type and volume of the elution solvent, amount of adsorbent, extraction time, desorption time and pH of the sample solution, were investigated and optimized. Validation experiments indicated that the developed method presented good linearity (R 2 >0.9961), satisfactory precision (RSD<6.7%), and high recovery (86.1–103.1%). The limits of detection ranged from 1.6 ng/L to 5.2 ng/L and the enrichment factor was in the range of 822–1423. The results indicated that the novel method had the advantages of convenience, good sensitivity, and high efficiency, and it could also be successfully applied to the analysis of PAEs in real samples. [ABSTRACT FROM AUTHOR]

In this study, the superparamagnetic attapulgite/Fe 3 O 4 /polyaniline (ATP/Fe 3 O 4 /PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe 3 O 4 formed by the redox reaction between aniline and Fe (III). The ATP/Fe 3 O 4 /PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry. Various experimental parameters affecting the ATP/Fe 3 O 4 /PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe 3 O 4 /PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r 2 ) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02–0.43 μg L −1 , and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52–5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78–6.86% and 1.66–8.41%, respectively. Finally, the proposed ATP/Fe 3 O 4 /PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs. [ABSTRACT FROM AUTHOR]

A new method by coupling surfactant assisted dispersive liquid liquid microextraction (SA-DLLME) with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was proposed for the analysis of gold nanoparticles (AuNPs) in environmental water samples. Effective separation of AuNPs from ionic gold species was achieved by using sodium thiosulphate as a complexing agent. Various experimental parameters affecting SA-DLLME of AuNPs, such as the organic solvent, organic solvent volume, pH of the sample, the kind of surfactant, surfactant concentration, vortex time, speed of centrifugation, centrifugation time, and different coating as well as sizes of AuNPs were investigated carefully. Furthermore, the interference of coexisting ions, dissolved organic matter (DOM) and other metal nanoparticles (NPs) were studied. Under the optimal conditions, a detection limit of 2.2 ng L − 1 and an enrichment factor of 152-fold was achieved for AuNPs, and the original morphology of the AuNPs could be maintained during the extraction process. The developed method was successfully applied for the analysis of AuNPs in environmental water samples, including tap water, the East Lake water, and the Yangtze River water, with recoveries in the range of 89.6–102%. Compared with the established methods for metal NPs analysis, the proposed method has the merits of simple and fast operation, low detection limit, high selectivity, good tolerance to the sample matrix and no digestion or dilution required. It provides an efficient quantification methodology for monitoring AuNPs' pollution in the environmental water and evaluating its toxicity. [ABSTRACT FROM AUTHOR]

This paper describes for the first time the use of a new extraction technique, based on fabric phase sorptive extraction (FPSE). This new mode proposes the extraction of the analytes in dynamic mode in order to reduce the extraction time. Dynamic fabric phase sorptive extraction (DFPSE) followed by liquid chromatography-tandem mass spectrometry was evaluated for the extraction of a group of pharmaceuticals and personal care products (PPCPs) from environmental water samples. Different parameters affecting the extraction were optimized and best conditions were achieved when 50 mL of sample at pH 3 was passed through 3 disks and analytes retained were eluted with 10 mL of ethyl acetate. The recoveries were higher than 60% for most of compounds with the exception of the most polar ones (between 8% and 38%). The analytical method was validated with environmental samples such as river water and effluent and influent wastewater, and good performance was obtained. The analysis of samples revealed the presence of some PPCPs at low ng L −1 concentrations. [ABSTRACT FROM AUTHOR]

In this work, the thermo-responsive polymer PNIPAM tethered to Fe 3 O 4 @SiO 2 @MOF core-shell magnetic microspheres was first synthesized by a surface-selective post-synthetic strategy and underwent highly efficient magnetic solid-phase extraction (MSPE) of alkylphenols from aqueous samples. Alkylphenols, including 4- tert -octylphenol (OP) and 4- n -nonylphenol (NP), were selected as target compounds. The sample quantification was carried out using LC–MS/MS in multiple reaction monitor (MRM) mode. Under optimal working conditions, the developed method showed good linearity in the range of 5–1000 ng L −1 , a low limit of detection (1.5 ng L −1 ), and good repeatability (relative standard deviation, <8%, n = 5) for NP and OP. Owning to the hydrophilic/hydrophobic switchable properties of the nanocomposite, high recoveries (78.7–104.3%) of alkylphenols were obtained under different extraction conditions. The levels of OP and NP in environmental samples collected from local river, lake and pond waters were analyzed using the developed method. It was believed that the synthesized material with the thermo-responsive coating, large surface areas and magnetic properties should have great potential in the extraction and removal of alkylphenols from environmental samples. [ABSTRACT FROM AUTHOR]

A novel method based on high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed for the sensitive determination of glyphosate and its major degradation product, AMPA in environmental water samples. The method involves the use of MS compatible mobile phases (0.1% formic acid in water and acetonitrile) for HPLC and direct analysis of water samples without sample derivatization. The method has been validated in different types of water matrices (drinking, surface and groundwater) by accuracy and precision studies with samples spiked at 0.1, 7.5 and 90 ppb. All mean accuracy values ranged from 85% to 112% for glyphosate and AMPA using both primary and secondary quantitative ion transitions (RSD ≤ 10%). Moreover, both primary and secondary ion transitions for glyphosate and AMPA can achieve the quantitation limits at 0.1 ppb. The linear dynamic range of the calibration curves were from 0.1 to 100 ppb for each analyte at each ion transitions with correlation coefficient higher than 0.997. [ABSTRACT FROM AUTHOR]

A novel online approach involving in-syringe magnetic stirring assisted dispersive liquid–liquid microextraction and derivatization coupled to gas chromatography–mass spectrometry has been developed for the determination of seven UV filters extensively used in cosmetic products in environmental water samples. The effect of parameters such as the type and volume of extraction solvent, dispersive solvent and derivatization agent, pH, ionic strength and stirring time, was studied using multivariate experimental design. Extraction, derivatization and preconcentration were simultaneously performed using acetone as dispersive solvent, N , O -bis(trimethylsilyl)trifluoroacetamide (BSTFA) as derivatization agent and trichloroethylene as extraction solvent. After stirring during 160 s, the sedimented phase was transferred to a rotary micro-volume injection valve (3 μL) and introduced by an air stream into the injector of the GC through a stainless-steel tube used as interface. The detection limits were in the range of 0.023–0.16 μg L −1 and good linearity was observed up to 500 μg L −1 of the studied UV filters, with R 2 ranging between 0.9829 and 0.9963. The inter-day precision expressed as relative standard deviation (n = 5) varied between 5.5 and 16.8%. Finally, the developed method was satisfactorily applied to assess the occurrence of the studied UV filters in seawater and pool water samples. Some of the studied UV filters were found in these samples and an add-recovery test was also successfully performed with recoveries between 82 and 111%. [ABSTRACT FROM AUTHOR]

In this work, covalent triazine frameworks (CTFs) were introduced in stir bar sorptive extraction (SBSE) and a novel polydimethylsiloxane(PDMS)/CTFs stir bar coating was prepared by sol–gel technique for the sorptive extraction of eight phenols (including phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p -chloro- m -cresol and 2,4-dichlorophenol, 2,4,6-trichlorophenol) from environmental water samples followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The prepared PDMS/CTFs coated stir bar showed good preparation reproducibility with the relative standard deviations (RSDs) ranging from 3.5 to 5.7% ( n = 7) in one batch, and from 3.7 to 9.3% ( n = 7) among different batches. Several parameters affecting SBSE of eight target phenols including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N = 3) were found to be in the range of 0.08–0.30 μg/L. The linear range was 0.25–500 μg/L for 2-nitrophenol, 0.5–500 μg/L for phenol, 2-chlorophenol, 4-nitrophenol as well as 2,4-dimethylphenol, and 1–500 μg/L for p -chloro- m -cresol, 2,4-dichlorophenol as well as 2,4,6-trichlorophenol, respectively. The intra-day relative standard deviations (RSDs) were in the range of 4.3–9.4% ( n = 7, c = 2 μg/L) and the enrichment factors ranged from 64.9 to 145.6 fold (theoretical enrichment factor was 200-fold). Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/CTFs stir bar showed better extraction efficiency for target phenol compounds. The proposed method was successfully applied to the analysis of phenols in environmental water samples and good relative recoveries were obtained with the spiking level at 2, 10, 50 μg/L, respectively. [ABSTRACT FROM AUTHOR]

A novel method based on aeration-assisted homogeneous liquid–liquid microextraction using high density solvent is presented, which is combined with inductively coupled plasma-mass spectroscopy in which simultaneous preconcentration and determination of thorium and uranium with arsenazo III as the chelating reagent is carried out. To achieve optimum conditions, several parameters such as pH, concentration of arsenazo III, extraction and homogenous solvent types and their volumes, salt concentration and extraction time were investigated. Under which, the calibration graphs were linear in the range of 0.5–600.0 ng L −1 for thorium and 0.3–550.0 ng L −1 for uranium. Good linearities were obtained for both analytes with R 2 values larger than 0.9990. The limits of detection (LOD, 3 S b / m , n =5) of this method were 0.12 and 0.09 ng L −1 , and the enrichment factors were estimated to be 370 and 410 for thorium and uranium, respectively. The proposed method was applied to determine the thorium and uranium in human hair and different environmental water samples. Acceptable recoveries ranged from 99.4% to 100.7% with standard deviation of 0.05 to 0.17. [ABSTRACT FROM AUTHOR]

A convenient method was developed for rapid determination of Pu in environmental water samples. The analytical procedure involves preconcentration of Pu using TEVA extraction chromatography implemented in a vacuum box setup, and measurement of 239 +240 Pu by low background liquid scintillation counter (LSC). Chromatographic behaviors of plutonium, uranium, thorium, and americium were investigated, and the size of chromatographic column, concentration and flow rate of uploaded medium/washing liquid, and composition of eluent of Pu(Cl − ) 6 2 − -on TEVA column were explored. The results show that all the above factors affect the adsorption and desorption of Pu(Cl − ) 6 2 − -on TEVA column. Decontamination factors of more than 1 × 10 4 for uranium and 1 × 10 3 for thorium and americium were achieved. Chemical yields of plutonium in the overall procedure range from 70% to 98% and a detection limit of 6 × 10 − 3 Bq L − 1 in 60 min counting time for 5 L of water samples were obtained. The method has been successfully applied for rapid and effective determination of low level Pu in water samples. The analytical results show a good agreement with the values obtained using the conventional method. Compared with the conventional analytical procedure, the time consumption and labor intensiveness of the new procedure were greatly reduced and the analysis throughput was greatly increased with low analysis cost. The method is applicable to routine and emergency radiometric assays. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new hydrogel sorbent was synthetized by using acrylic polymer and amylodextrin. • The sorbent was prepared through facile strategy by low cost and biocompatible materials. • The sorbent was used in pipette-tip micro solid phase extraction of triazole fungicides. • The extraction procedure was followed by ion mobility spectrometry as a fast detection method. • The proposed method indicated excellent extraction recoveries and favorable figures of merit. Triazole compounds have been globally used for controlling fungal diseases such as rusts, powdery mildew, and many leaf-spotting fungi. These compounds also have adverse effects on the environment and human health. In the present work, a hydrogel-based sorbent was synthesized by a combination of hydrophilic acrylic polymer and biodegradable amylodextrin. The sorbent was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) surface area, elemental CHN analysis, field emission scanning electron microscopy (FE-SEM), and zeta potential. The synthesized hydrogel was used as a green sorbent in the pipette-tip micro-solid phase extraction procedure for extraction and quantification of triazole fungicides (penconazole, hexaconazole, and tebuconazole) in environmental water samples. The corona discharge-ion mobility spectrometry (CD-IMS) was used as a rapid and sensitive detection technique. The effects of important variables on the extraction efficiency were optimized by response surface methodology (RSM). The proposed method provided good linearity (r2 ≥ 0.995) over a concentration range of 0.5–1000 ng/mL, acceptable intra-day RSD (≤ 5.7%, n = 5) and inter-day RSD (≤ 8.7%, n = 5), low limits of detection (0.10–0.20 ng/mL), good preconcentration factors (16.9–17.9 times), and high extraction recoveries (93.1–98.3%) under optimum extraction conditions. The extraction conditions were as follows: the amount of sorbent: 6.0 mg, pH of sample solution: 7.5, the flow rate of sample solution: 2.0 mL/min, adsorption time: 16.5 min, volume of desorption solvent: 1.1 mL, the flow rate of desorption solvent: 0.5 mL/min, and desorption time: 11.7 min. Finally, the proposed method was successfully applied for the quantification of triazoles in river and agricultural water samples. [ABSTRACT FROM AUTHOR]

[Display omitted] In the present study, electrospun zeolitic imidazolate framework-8/poly(lactic acid) nanofibers were successfully synthesized and characterized as a potential nanosorbent for the pipette-tip micro-solid phase extraction of chlorpropham, pirimicarb, carbaryl, and methiocarb carbamate insecticides from environmental water samples. The extraction procedure was followed by gas chromatography/mass spectrometry separation and determination of the target analytes. All the effective parameters of the extraction procedure were optimized through the one variable at-a-time method. Thanks to the very simple extraction procedure as well as the application of electrospun nanofibers with high surface area, the four analytes were efficiently extracted with as lowest extraction times as practicable. Under the optimal conditions, the calibration plots of the analytes were obtained within broad linear dynamic ranges of 0.5 – 150 ng mL−1 for chlorpropham and pirimicarb plus 1.0 – 175 ng mL−1 for carbaryl and methiocarb, respectively. Besides, limits of detection as low as 0.2 and 0.15 ng mL−1 for chlorpropham and pirimicarb, respectively, as well as 0.5 ng mL−1 for carbaryl and methiocarb indicate the favorable sensitivity of the analytical procedure. The applicability of the developed method was evaluated by quantitative determination of the target analytes in four different environmental water samples. Relative recoveries higher than 88.0% shows the acceptable accuracy of the method in the quantitative determination of the four carbamate insecticides. [ABSTRACT FROM AUTHOR]

After the formation of dithizone with metal ion complexes, a selective Raman detection method for the Zn 2+ ions in aqueous solutions was developed by observing the intensity change of the ring mode peaks at ∼1585 cm −1 on gold nanoparticles (AuNPs). At high concentrations of Zn 2+ ions, the conformation of the dithizone complex may have different orientations on AuNPs to yield the spectral changes at ca. ∼510 and ∼1585 cm −1 . The concentration dependent spectra changes indicated that a detection limit would be in the submicromolar region of Zn 2+ ions. The other ions of Mg 2+ , K + , Fe 3+ , Hg 2+ , Co 2+ , Fe 2+ , Pb 2+ , Cu 2+ , Ni 2+ , Cr 3+ , NH 4 + , Cd 2+ , Na + , Ca 2+ , and Mn 2+ at micromolar concentrations of 1 μM did not produce such spectral changes. The detection limit based on the Raman band intensities was estimated to be as low as 500 nM of Zn 2+ ion in aqueous solutions. The three real samples of tap, river, and seawater were tested under the interference of the commonly existing interfering ions. Despite the presence of highly concentrated Na, Ca, Mg, and K, our interfacial spectroscopic methodology of Zn 2+ determination could be applied in the environmental water samples. [ABSTRACT FROM AUTHOR]

In this study, a stable cadmium(II)-based metal-organic framework (MOF) material was designed and used as a sorbent for the dispersive solid-phase extraction ( d SPE) of polybrominated diphenyl ethers (PBDEs) in environmental water samples. Gas chromatography coupled with triple quadrupole mass spectrometer (GC–MS/MS), working in the negative chemical ionization mode, was used to quantify the target analytes. Characterization of the material was performed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), elementary analyses (EA) and thermogravimetric analyses (TGA). The synthesized rod shape MOF is on the micro level in size and has excellent chemical and solvent stability. The extraction conditions, including the extraction time, temperature and ionic strength, were examined systematically using response surface methodology (RSM). Under optimized conditions, the method that was developed showed an excellent extraction performance. Good linearity ( R 2 > 0.99) within the concentration range of 0.25–250 ng L −1 was obtained. Low limits of detection (0.08–0.15 ng L −1 , signal-to-noise ratio = 3:1) and good precision (relative standard deviation <12%, n = 6) were achieved. The developed method was applied to analyze natural and spiked environmental water samples. [ABSTRACT FROM AUTHOR]

A new sorptive extraction technique, fabric phase sorptive extraction (FPSE), using different coating chemistries: non-polar sol–gel poly(dimethyldiphenylsiloxane) (PDMDPS), medium polar sol–gel poly(tetrahydrofuran) (PTHF), and polar sol–gel poly(ethylene glycol)–block-poly(propylene glycol)–block-poly(ethylene glycol) (PEG–PPG–PEG triblock) and sol–gel Carbowax 20M were evaluated to extract a group of pharmaceuticals and personal care products (PPCPs) with wide range of polarity from environmental aqueous samples. Different parameters affecting FPSE such as sample pH, stirring speed, addition of salt, extraction time, sample volume, elution solvent and desorption time were optimized for each sorbent coated FPSE media. Under optimum conditions, FPSE media coated with sol–gel Carbowax 20M provided the highest absolute recoveries (77–85%) for majority of the analytes with the exception of the most polar ones. Nevertheless, all four sorbents offered better recovery compared to the commercially available coating for stir-bar sorptive extraction based on Ethylene Glycol/Silicone (EG/Silicone). The method based on FPSE with sol–gel Carbowax 20M media and liquid chromatography–(electrospray ionization) tandem mass spectrometry (LC–(ESI) MS/MS) was developed and validated for environmental water samples. Good apparent recoveries (41–80%), detection limits (1–50 ng L −1 ), repeatability (%RSD<15%, n =5) and reproducibility (%RSD<18%, n =5) were achieved. [ABSTRACT FROM AUTHOR]

Cisplatin is still widely used for treatment of numerous types of tumours. Different speciation methods have been applied to study behaviour of the intact drug and its individual biotransformation species in various clinical samples. These methods are mainly based on electrophoresis, size exclusion (SEC) or ion chromatography (IC) techniques coupled to inductively coupled plasma mass spectrometry (ICP–MS). Hydrophilic interaction liquid chromatography (HILIC), which is a common technique for separation of polar substances, was rarely applied for separation of cisplatin and its hydrolysed metabolites. There is also a lack of information available on the occurrence of cisplatin and its hydrolysed complexes in the environmental waters. In the present study the concentrations of Pt were determined in hospital wastewaters by ICP–MS. A procedure for separation of cisplatin and its aqueous hydrolysed complexes by the use of HILIC column was optimized. Quantification of separated Pt species was performed by isotope dilution (ID)–ICP–MS procedure. Low limits of detection (LODs) and quantification (LOQs) were obtained for cisplatin and its hydrolysed complexes ranging from 0.0273 to 0.1726 ng Pt/mL and from 0.0909 to 0.5753 ng Pt/mL, respectively. Good repeatability of the procedure with relative standard deviation (RSD) lower than ±2.3% was obtained. The column recoveries, which ranged from 95 to 101%, indicated that the procedure developed enabled quantitative speciation analysis of aqueous cisplatin complexes. The ZIC-HILIC–ID–ICP–MS procedure was successfully applied in speciation of cisplatin in spiked hospital wastewater samples. [ABSTRACT FROM AUTHOR]

The nitrogen donor ligand was functionalized with polarable mesoporous silica as composite adsorbent, by a cost-effective and environmentally friendly procedure, for highly selective copper (Cu(II)) ions detection and removal from water. The nitrogen donor ligand of N , N (octane-1,8-diylidene)di(2-hydroxy-3,5-dimethylaniline) was synthesized to be specific to Cu(II) ions. The composite adsorbent permitted fast and specific Cu(II) ions capturing via colorimetric naked-eye detection based on stable complexation [Cu(II)–ligand] n + mechanism. The effect of pH value, interferential metal ions, initial Cu(II) concentration, and contact time on adsorption capability were investigated systematically. The adsorbent was selective toward Cu(II) as shown by a light yellow to green color change. This was characterized by UV–vis spectroscopy and the color change was observed for the visual detection of Cu(II) ions. The ions selectivity of the adsorbent toward Cu(II) was determined by changes in UV–vis reflectance spectra. However, the presence of competing ions showed no interference for the detection of Cu(II) ion by the composite adsorbent. The results demonstrated that the composite adsorbent exhibited excellent sorption performance for Cu(II) ions. The low detection limit and sorption capacity of the adsorbent were 0.10 μg/L and 200.80 mg/g, respectively. The adsorbed Cu(II) was eluted with suitable eluent and simultaneously regenerated into the initial form for next operation without significant deterioration in its nanostructure case cavities. The data also confirmed that the adsorbent is a cost-effective and environmentally friendly procedure for Cu(II) treatment. Therefore, the composite adsorbent can be considered as a potential adsorbent for Cu(II) ions monitoring and removal from wastewater. [ABSTRACT FROM AUTHOR]

This study reports a deep eutectic solvent based dispersive liquid-liquid microextraction (DES-DLLME) to extract aromatic amines (4-chloroaniline, 3-nitroaniline, 2-naphtylamine) in environmental water samples before their HPLC-UV determination. The hydrophobic deep eutectic solvent (DES) was prepared by mixing bis(2-ethylhexyl) phosphate (BEHP) as a hydrogen bond acceptor and phenol as a hydrogen bond donor. Affecting factors on the extraction of the aromatic amines were investigated and optimized. Optimum conditions were: DES type: BHHP-Ph ratio: 1 to 2; pH of solution: 8.0; DES volume: 80 µL, salt amount: 10% (w/v). Under optimum conditions, the developed method showed a wide linear range of 0.2–200 µg L−1 (R2 ≥ 0.99) with satisfactory recoveries (≥90.0%). The limit of detections (LODs) and limit of quantifications (LOQs) were in the range of 0.07–0.17 µg L−1 and 0.2–0.5 µg L−1, respectively. The enrichment factors were 170, 180 and 190 for 4-chloroaninile, 3-nitroaniline, 2-naphtylamine, respectively. Based on obtained results, the proposed method is straightforward, efficient, sensitive, and eco-friendly for the extracting and determining of the aromatic amines in environmental water samples. [ABSTRACT FROM AUTHOR]

A new solid phase extractor named silica gel immobilized indapamide (4-chloro-N-(2-methyl-2,3-dihydroindol-1-yl)-3-sulfamoylbenzamide) (SG-INDP) was synthesized by microwave free-solvent technique as a new environmentally friendly modification method. This new phase was investigated for removal of copper ions from aqueous media. It was characterized by the FT-IR, scan electron microscope and X-ray diffraction analyses. The effects of sample pH, time of equilibrium, sorbent weight, copper ions concentrations and interfering ions were studied and optimized using batch technique at room temperature. The maximum percentage of extraction of Cu(II) (99.90 ± 0.1%) using SG-INDP was achieved. The fast adsorption equilibrium could be reached within 20 min and the kinetic data were fitted well by a pseudo-second-order equation ( r 2 = 0.999). Results of sorption isotherms of the sorbent were better fitted with the Langmuir ( r 2 = 0.994) and Freundlich ( r 2 = 0.985) models. The new synthesized solid phase extractor was applied for removal of Cu(II) from natural water samples. [ABSTRACT FROM AUTHOR]