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The present work aimed at decorating halloysite nanotubes (HNT) with magnetic Fe

Trace elements are widespread contaminants that can potentially threaten ecosystems and human health. Considering their distribution and toxicity, monitoring their presence in animals represents a priority in environmental risk assessment. Migratory birds have been suggested to be useful biomonitors for trace elements because they can provide information on contaminants even from remote areas that they may exploit during their life cycle. The aim of this study was to analyse the contamination fingerprint of trace elements of African non-breeding staging grounds and European breeding areas in a long-distance migratory passerine bird, the barn swallow (Hirundo rustica). We collected feathers grown in the African non-breeding grounds and those grown in the breeding areas of Northern Italy and measured the levels of 12 trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn) by DRC-ICP-MS. Multivariate analysis showed that elemental profiles of feathers grown in African non-breeding areas and in the Italian breeding ones clearly differed, with feathers grown in Africa showing higher concentrations of Al, Cu, Fe, Mn and Ni, but lower concentrations of As, Se and Zn, compared to those grown in Italy. In addition, levels of trace elements were age-dependent, with higher levels in older individuals than in younger ones. Our results add to the growing evidence that feathers of long-distance migratory birds are useful tools to monitor trace elements contamination profiles across continents. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-020-11597-z.

The photodegradation process of seven glucocorticoids (GCs), cortisone (CORT), hydrocortisone (HCORT), betamethasone (BETA), dexamethasone (DEXA), prednisone (PRED), prednisolone (PREDLO) and triamcinolone (TRIAM) was studied in tap and river water at a concentration close to the environmental ones. All drugs underwent sunlight degradation according to a pseudo-first-order decay. The kinetic constants ranged from 0.00082 min&minus, 1 for CORT to 0.024 min&minus, 1 for PRED and PREDLO. The photo-generated products were identified by high-pressure liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The main steps of the degradation pathways were the oxidative cleavage of the chain 17 for CORT, HCORT and the rearrangement of the cyclohexadiene moiety for the other GCs. The acute and chronic toxicity of GCs and of their photoproducts was assessed by the V. fischeri and P.subcapitata inhibition assays. The bioassays revealed no significant differences in toxicity between the parent compounds and their photoproducts, but the two organisms showed different responses. All samples produced a moderate acute toxic effect on V. fisheri and no one in the chronic tests. On the contrary, evident hormesis or eutrophic effect was produced on the algae, especially for long-term contact.

Two different zinc-based metal-organic frameworks (MOFs) were investigated to remove one of the most used fluoroquinolone antibiotic, Ofloxacin (OFL), from polluted water. The most common zeolitic imidazolate framework-8 (ZIF-8) and the green Zn(II) and benzene-1,3,5-tri-carboxylate (Zn3(BTC)2) were prepared through a facile synthetic route and characterized by means of Fourier-Transform Infrared (FT-IR) Spectroscopy, X-ray Powder Diffraction (XRPD), and Scanning Electron Microscopy (SEM) analyses. The two MOFs were compared in terms of both adsorption and kinetic aspects under real conditions (tap water, natural pH). Results showed that OFL was adsorbed in remarkable amounts, 95 ± 10 and 25.3 ± 0.8 mg g−1 on ZIF-8 and Zn3(BTC)2, respectively, following different mechanisms. Specifically, a Langmuir model well described the ZIF-8 profile, while for Zn3(BTC)2, cooperative adsorption occurred. Moreover the kinetic results were quite different, pseudo-second-order and sigmoidal, respectively. The suitability of ZIF-8 and Zn3(BTC)2 as adsorbent phases for water depollution was tested on tap water samples spiked with OFL 10 µg L−1. The obtained removal efficiencies, of 88% for ZIF-8 and 72% for Zn3(BTC)2, make these materials promising candidates for removing fluoroquinolone antibiotics (FQs) from polluted waters, notwithstanding their limited reusability in tap water, as demonstrated by in-depth characterization of the two MOFs after usage.

The concentration of 12 elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) has been investigated in the feathers of three species of Ardeidae, namely the Grey Heron Ardea cinerea, the Little Egret Egretta garzetta, and the Cattle Egret Bubulcus ibis, all breeding at a colony located in the southern Padana Plain (NW Italy). This study is a first step for an evaluation of possible direct effects of these elements on chicks&rsquo, survival and growth rate. Fe, Zn, Cu, and Mn were in the range 7&ndash, 69 mg Kg&minus, 1, while lower levels of Pb, Ni, As, and Se (0.27&ndash, 1.45 mg Kg&minus, 1) were measured. Co, Cd, and Cr were close to the method detection limits (MDLs) in all the species. The measured concentrations of the most abundant trace elements, such as Zn and Cu, seem to reflect the geochemical pattern of the background (running water and soil), while Hg concentration is lower and it appears to be biomagnified, particularly in Grey Heron feathers. Its concentration is higher in adults than in chicks, and it differs among the three species, as it is closely related to the fish-based dietary pattern. The measured trace elements&rsquo, concentrations are below the threshold levels in all the heron species, and consequently, harmful and acute effects on the local population are unlikely, the conservation status of herons populations in northern Italy is probably more affected by other factors, such as climate changes, altered aquatic environment, and, consequently, food quality.

The purpose of this study was to set up a sensitive method for the simultaneous determination of phycotoxins and cyanotoxins&mdash, emerging pollutants with different structures and harmful properties (hepatotoxicity, neurotoxicity and cytotoxicity)&mdash, in environmental waters. Due to the low concentrations detected in these samples, a pre-concentration step is required and here it was performed in a single step with a commercial cartridge (Strata&trade, X), achieving enrichment factors up to 200 and satisfactory recovery (R = 70-118%) in different aqueous matrices. After solid-phase extraction (SPE), toxins were separated and quantified by High Performance Liquid Chromatography- Heated ElectroSpray Ionisation Tandem Mass Spectrometry (HPLC-HESI-MS/MS) in Multiple Reaction Monitoring (MRM) mode. An analytical evaluation of the proposed method was done based on the analytical figures of merit, such as precision and trueness, linearity, selectivity, and sensitivity, and it turned out to be a robust tool for the quantification of ng L-1 levels, phycotoxins and cyanotoxins in both freshwater and saltwater samples.

Aim and novelty of this work are the development of a simple and straightforward analytical procedure for multiclass determination of steroid hormones in human plasma. The method entails a single pre-treatment step based on solid-phase extraction using a recently proposed sorbent phase (HA-C@silica). This is easily prepared with good reproducibility via pyrolysis of humic acids onto silica, and not yet tested in biological fluids. It proved to be advantageous as it showed poor affinity for the protein matrix constituents while quantitatively extracting and pre-concentrating the target analytes. Indeed, as demonstrated in bovine serum albumin solution, up to ca. 90% protein is not retained by the sorbent, similarly to the behaviour of restricted access carbon nanotubes, tested for comparison. The high albumin exclusion allowed a satisfactory clean-up avoiding protein precipitation and centrifugation before extraction. The extraction procedure, optimized by a chemometric approach (23 experimental design) in BSA solution, provided quantitative recovery (76–119%, n = 3) for all steroids working with 1:8-diluted plasma (2 mL) and 100 mg HA-C@silica. Before analytes elution by 1 mL methanol-acetonitrile (1:1, v/v), selective washings (2% v/v formic acid and 30% v/v methanol) were applied to remove the small fraction of retained proteins, thus obtaining very clean SPE extracts to be analyzed by HPLC-ESI-MS/MS. This allowed identification/quantification (MRM mode) at few ng mL−1 by a single chromatographic run. The procedure was verified in blank-certified foetal bovine serum (spikes 10–100 ng mL−1), obtaining good recovery and suitable inter-day precision (RSDs

This work focuses on the extraction and determination of contaminants of environmental concern belonging to the classes of benzotriazoles and benzothiazoles from tap and raw river water samples. The sorbent, recently proposed by this research group, prepared by pyrolysis of humic acids (HAs) onto silica microparticles (HA-C@silica), was tested for fixed-bed SPE of benzotriazole and benzothiazole compounds by modulating its sorption affinity through the carbon loading. This was successfully increased from 10 to 20 wt% HAs and the obtained material, characterized by different techniques, provided quantitative adsorption at the sample native pH (7.5–8), for 50–250 mL samples spiked with each compound at the micrograms per litre levels. After extraction, the analytes were simultaneously desorbed by 4 mL methanol, even more reducible to small volume before HPLC–HESI-MS/MS analysis. Recovery was satisfactory for all compounds, ranging from 70 to 114%, with RSD values ≤ 16% (n = 3). The developed procedure allows quantitation of benzotriazoles at concentrations far below the environmental trigger limits. HA-C@silica turned out to be appealing in comparison with the commercial sorbents in terms of cost, recovery and pre-concentration for determination of such pollutants in actual surface waters. Good reproducibility was observed on independent HA-C@silica preparations.

Oxidized graphitic carbon nitride (o-g-C3N4) and Evonik AEROXIDE® P25 TiO2 were compared for lab-scale photocatalytic H2 evolution from aqueous sacrificial biomass-derivatives, under simulated solar light. Experiments in aqueous starch using Pt or Cu–Ni as the co-catalysts indicated that H2 production is affected by co-catalyst type and loading, with the greatest hydrogen evolution rates (HER) up to 453 and 806 μmol g−1 h−1 using TiO2 coupled with 3 wt% Cu–Ni or 0.5 wt% Pt, respectively. Despite the lower surface area, o-g-C3N4 gave HERs up to 168 and 593 μmol g−1 h−1 coupled with 3 wt% Cu–Ni or 3 wt% Pt. From mono- and di-saccharide solutions, H2 evolution was in the range 504–1170 μmol g−1 h−1 for Pt/TiO2 and 339–912 μmol g−1 h−1 for Cu–Ni/TiO2, respectively; o-g-C3N4 was efficient as well, providing HERs of 90–610 μmol g−1 h−1. The semiconductors were tested in sugar-rich wastewaters obtaining HERs up to 286 μmol g−1 h−1. Although HERs were lower compared to Pt/TiO2, a cheap, eco-friendly and non-nanometric catalyst such as o-g-C3N4, coupled to non-noble metals, provided a more sustainable H2 evolution.

Silica-supported pyrolyzed lignin (pLG@silica) was investigated as a solid sorbent for the pre-concentration of rare earth elements (REE) from natural waters followed by inductively coupled plasma mass spectrometry (ICP-MS) analysis. The carbon-based material was easily prepared by pyrolytic treatment of lignin at 600 °C after its adsorption onto silica micro-particles. pLG@silica was characterized by scanning electron microscopy (SEM), surface area measurements (BET method), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), point of zero charge measurement, and X-ray photoelectron spectroscopy (XPS). The as-prepared material (50 mg) was tested as fixed-bed sorbent for the solid-phase extraction (SPE) of tap, river, and sea water samples spiked with REE in the 10–150 ng L−1 range, followed by ICP-MS analysis. A quantitative adsorption was observed for all REE with recoveries in the range of 72–118%. A suitable inter-day precision (RSDs 5–12%, n = 3) was obtained. Sample volumes up to 250 mL provided enrichment factors up to 100. The method detection and quantification limits (MDLs and MQLs) were in the range of 0.4–0.6 ng L−1 and 1–2 ng L−1, respectively. The batch-to-batch reproducibility was verified on four pLG@silica independent preparations. As remarkable advantages, pLG@silica proved to be of easy preparation using a waste material, inexpensive, and reusable for at least 20 SPE cycles.

Chemically modified g-C3N4 for the photocatalytic H2 evolution from water was explored. Bulk g-C3N4 was treated in hot HNO3 aqueous solution to obtain the oxidized material (o-g-C3N4), tested in water containing glucose as model water-soluble sacrificial biomass, using Pt as co-catalyst, under simulated solar light. The behaviour of o-g-C3N4 was studied in relation with catalyst amount, Pt loading, glucose concentration. Results showed that H2 production is favoured by increasing glucose concentration up to 0.1 M and Pt loading up to 3 wt%, and it resulted strongly enhanced using small amount of o-g-C3N4 (0.25 g L−1). o-g-C3N4 possesses superior photocatalytic activity (∼26-fold higher) compared to pristine g-C3N4, with H2 evolution further improved by ultrasound-assisted exfoliation and evolution rates up to ca. 1370 μmol h−1 per gram of catalyst, with excellent reproducibility (RSD

In this work, red mud (RM) and spinel iron oxide nanoparticles (SPIONs) were added to pure silica/alumina sources (SAs) and fly ash (FA) with the aim of synthesizing and investigating the magnetic behavior of different zeolites. SAs were used to synthesize zeolite with LTA topology (zeolite A) with the addition of both red mud and spinel iron oxide nanoparticles. FA and RM were mixed to synthesize sodalite whereas only FA with the addition of SPIONs was used to form zeolite with FAU-topology (zeolite X). All the synthetic products showed magnetic properties. However, zeolites with spinel iron oxide nanoparticles (zeolites A and X) showed ferromagnetic-like behavior. Sodalite was characterized by a reduction in saturation magnetization, whereas zeolite A with red mud displayed antiferromagnetic behavior. For the first time, all the synthetic products were tested for polluted water remediation by a persistent emerging contaminant, ofloxacin (OFL) antibiotic. The four zeolite types showed good adsorption affinity towards OFL under actual conditions (tap water, natural pH). All materials were also tested for OFL removal in real waters spiked with OFL 10 µg L−1. Satisfactory recoveries (90–92% in tap water, 83–87% in river water) were obtained for the two zeolites synthesized from industrial waste materials.

This work shows a novel analytical method for the simultaneous extraction of environmental emerging contaminants as benzenesulfonamides (BSAs), benzotriazoles (BTRs), and benzothiazoles (BTs) from water samples. Pristine multi-walled carbon nanotubes (MWCNTs), not yet tested for such analytes, are here employed as the sorbent phase for dispersive solid-phase extraction (d-SPE) followed by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-HESI-MS/MS). Quantitative sorption is gained by treating 50 mL sample with 100 mg MWCNTs (2 g L-1) in 10 min contact, both in tap and raw river water. After sorption, the analytes are quantitatively desorbed by microwaves (20 min, 160 °C, 250 W) by using 5 mL methanol-ethylacetate-acetic acid (10:70:20, v/v), according to the indications obtained by a chemometric study. The extract is reduced to small volume before analysis, thus reaching overall enrichment factors up to 400. Recovery of the entire procedure, evaluated on tap and surface water samples spiked with 0.1/0.5-50 μg L-1 of each analyte, was in the range 70-116%, with excellent inter-day precision (RSD

TiO2 sepiolite and zeolite composites, as well the corresponding N-doped composites, synthesized through a sol&ndash, gel method, were tested for the photocatalytic degradation of a widespread fluoroquinolone antibiotic (ofloxacin) under environmental conditions. The catalysts were characterized by X-ray diffraction (XRD), Brunauer&ndash, Emmett&ndash, Teller (BET), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS) analyses. A complete drug degradation occurred in 10&ndash, 15 min in the presence of both TiO2 sepiolite and zeolite catalysts, and in 20&ndash, 30 min with the N-doped ones. Sepiolite proved to be a better TiO2 support compared to the most common zeolite both in terms of adsorption capacity and photocatalytic efficiency in pollutants degradation. The influence of nitrogen doping (red shift from 3.2 to 3.0 eV) was also investigated. Although it was blurred by a marked increase of the particle dimension and thus a decrease of the specific surface area of the doped catalysts, it allowed a faster drug removal than direct photolysis. The photochemical paths and photoproducts were investigated, too.

Untreated rice husk (RH) was evaluated as solid-phase extraction (SPE) sorbent for Fluoroquinolone antibiotics (FQs). This natural material, made of cellulose, hemicellulose, lignin and silica, and containing various functional groups, i.e., carboxyl, hydroxyl, and amidogen residues, is a potential sorbent material for polar aromatics like FQs. First, the RH capability to adsorb FQ species from water was studied by batch sorption experiments in tap and river waters, and the experimental data, fitted by the Langmuir model, gave adsorption capacities up to 32 mg g−1. Then, RH was tested as column-packed sorbent for pre-concentration of tap and not tampered river waters spiked with six widely employed FQs, i.e., Ciprofloxacin, Danofloxacin, Enrofloxacin, Levofloxacin, Marbofloxacin, and Norfloxacin. The analytes were quantitatively adsorbed on the RH cartridge at the native pH, simultaneously eluted by NH3–MeOH mixture, separated in an 8 min ultrahigh-performance liquid chromatography run and quantified/confirmed by electrospray ionization tandem mass spectrometric detection in single reaction monitoring mode. Recoveries in the range 71–120% were observed (RSD

The article describes a carbon-based material for solid-phase extraction (SPE) of fluoroquinolones from waters. It was obtained by pyrolytic deposition of Kraft lignin (LG) on silica particles. Marbofloxacin (MAR) and enrofloxacin (ENR) were chosen as model contaminants. The material was prepared by first adsorbing LG onto silica microparticles, this followed by pyrolytic treatment at 1200 °C for 2 h. Silica-supported carbon was characterized by scanning electron microscopy, surface area measurement (by BET), thermogravimetric analysis, and electron paramagnetic resonance. The carbon-coated silica particles were then tested as a column packing for SPE of MAR and ENR from spiked tap and river waters. Quantitative adsorption was observed at pH values of ~7.5 for both drugs. They were eluted with a 70:30 mixture of aqueous tetrabutylammonium hydroxide and acetonitrile and then quantified by HPLC coupled to fluorescence detection. Samples spiked with MAR and ENR in the range from 10 to 1000 ng·L−1 gave recoveries ranging from 70 to 116% (for n = 3). Good inter-day precision (with RSDs between 7 and 16%) was observed for 20–1000 ng·L−1 spikes, also in natural river water. Sample volumes up to 500 mL provided enrichment factors up to 125, and this makes this material useful for determination of the two drugs at environmentally significant levels which are as low as a few ng·L−1. The batch-to-batch reproducibility was verified for 3 preparations. The sorbent was successfully applied to the determination of these drugs in environmental waters.

Sepiolite is studied as sorbent for removal of Fluoroquinolone (FQ) contaminants from water. Marbofloxacin (MAR) and Enrofloxacin (ENR) were chosen as model FQs since they are the two most commonly employed veterinary FQs in livestock farming in northern Italy. Adsorption experiments on two sepiolites (SP-1 and SSE16) were carried out in tap water at pH 7.5 to better mimic real conditions. The sorption experimental data were fitted by Freundlich, Langmuir and S-Logistic1 models. The latter better described MAR and ENR adsorptions. Adsorption capacities of SP-1 and SSE16, respectively, were 132 mg g(-1) and 121 mg g(-1) for MAR, and 112 mg g(-1) and 93 mg g(-1) for ENR. X-ray powder diffraction, performed on clay samples enriched with each FQ and on the pristine clays, showed no substantial differences between the two sepiolites and evidenced no significant structural changes after FQs uptake, as also verified by infrared spectroscopy. This indicates that adsorption occurs only on the external surface of the mineral and not in the intracrystalline microporosity, likely due to the interaction between the FQ carboxylic group and the sepiolite surface. For the first time solid-state photodegradation of the adsorbed FQs was investigated for regenerating the sorbent. Results showed that the adsorbed drugs are effectively photodegraded by solar light, thus allowing sepiolite to be reused. The efficiency of this material for remediation of contaminated water was proved on ditch water, collected downstream a swine farm, containing some tens of ng L(-1) of MAR and ENR.

This paper provides a review of the latest applications of carbon-based materials for magnetic solid-phase extraction (MSPE), an advantageous sample pre-treatment increasingly adopted in analytical chemistry. In particular, this review focuses on the pre-concentration procedures developed for the determination of various classes of pollutants in environmental matrices. Beside the recent advances in the application of carbon nanotubes (CNTs), the newest carbonaceous materials have been considered, namely differently arranged nanocarbons (NCs), graphene (GN) and graphitic carbon nitride (g-C3N4). The analytical performance of the magnetic composites was critically discussed in relation to the physical–chemical properties resultant from the synthetic routes. The new sorbents generally afforded high extraction efficiency, good selectivity in complex matrices and durability for tens adsorption/desorption cycles, mainly due to high surface area, chemical stability, dispersibility in aqueous solution and, importantly, multi-type interaction. In particular, this was greatly enhanced by combining magnetic GN with other substrates or using derivatized GN, obtaining mixed-mode sorbents. The ease of preparation, durability and high enrichment factor make this new generation of MSPE carbon-based sorbents a valid alternative to the commercial solid phases.

Two different zinc-based metal-organic frameworks (MOFs) were investigated to remove one of the most used fluoroquinolone antibiotic, Ofloxacin (OFL), from polluted water. The most common zeolitic imidazolate framework-8 (ZIF-8) and the green Zn(II) and benzene-1,3,5-tri-carboxylate (Zn3(BTC)2) were prepared through a facile synthetic route and characterized by means of Fourier-Transform Infrared (FT-IR) Spectroscopy, X-Ray Powder Diffraction (XRPD), and Scanning Electron Microscopy (SEM) analyses. The two MOFs were compared in terms of both adsorption and kinetic aspects under real conditions (tap water, natural pH). Results showed that OFL was adsorbed in remarkable amounts, 95 ± 10 and 25.3 ± 0.8 mg g−1 on ZIF-8 and Zn3(BTC)2, respectively, following different mechanisms. Specifically, a Langmuir model well described the ZIF-8 profile, while for Zn3(BTC)2, cooperative adsorption occurred. Moreover the kinetic results were quite different, pseudo-second-order and sigmoidal, respectively. The suitability of ZIF-8 and Zn3(BTC)2 as adsorbent phases for water depollution was tested on tap water samples spiked with OFL 10 µg L−1. The obtained removal efficiencies, of 88% for ZIF-8 and 72% for Zn3(BTC)2, make these materials promising candidates for removing fluoroquinolone antibiotics (FQs) from polluted waters, notwithstanding their limited reusability in tap water, as demonstrated by in-depth characterization of the two MOFs after usage.

Photocatalysis by semiconductors is considered one of the most promising advanced oxidation processes (AOPs) and TiO2 is the most well-studied material for the removal of contaminants from the aquatic system. Over the last 20 years, pharmaceuticals have been the most investigated pollutants. They re-enter the environment almost unmodified or slightly metabolized, especially in the aquatic environment, since the traditional urban wastewater treatment plants (WWTPs) are not able to abate them. Due to their continuous input, persistence in the environment, and unpleasant effects even at low concentrations, drugs are considered contaminants of emerging concern (ECs). Among these, we chose fluoroquinolone (FQ) antibiotics as an environmental probe for assessing the role of TiO2 photocatalysis in the degradation of recalcitrant pollutants under environmental conditions and detoxification of surface waters and wastewaters. Due to their widespread diffusion, their presence in the list of the most persistent pollutants, and because they have been deeply investigated and their multiform photochemistry is well-known, they are able to supply rich information, both chemical and toxicological, on all key steps of the oxidative degradation process. The present review article explores, in a non-exhaustive way, the relationship among pollution, toxicity and remediation through titanium dioxide photocatalysis, with particular attention to the toxicological aspect. By using FQs as the probe, in depth indications about the different phases of the process were obtained, and the results reported in this paper may be useful in the improvement of large-scale applications of this technology, and—through generally valid methods—they could be deployed to other pharmaceuticals and emerging recalcitrant contaminants.

Nanosized titanium dioxide immobilized on silica gel was synthesized and used as fixed-bed phase for V(V) pre-concentration, followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Three different sorbents were prepared by sol–gel method starting from a mixture of titanium isopropoxide, 2-propanol and water, and characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and BET analysis. V(V), the most stable and toxic oxidation state of the element, present in water and beverages samples, was selectively sorbed, pre-concentrated, quantitatively eluted by 0.1 M HCl and analyzed by ICP-OES. The effectiveness of the procedure was first assessed on tap water enriched with 1 μg L−1 of V(V) obtaining recoveries up to 92% (n = 4). The pre-concentration step was then optimized for complex matrices such as tea infusions and red and white wines. The reliability of the procedure was assessed on the same beverages samples spiked with 20–250 μg L−1. Quantitative recoveries (82–95%, n = 4) were assured avoiding any sample pre-treatment, generally essential in such complex matrices, obtaining good precision (RSD

Benzotriazoles (BTRs), benzothiazoles (BTs) and benzenesulfonamides (BSAs), compounds largely used in industrial and household applications, are ubiquitous emerging contaminants. In this work a novel, straightforward procedure for the simultaneous determination of two BTRs (1H-benzotriazole, 5-methyl-1H-benzotriazole), three BTs (benzothiazole, 2-hydroxybenzothiazole, 2-methylthiobenzothiazole) and two BSAs (benzenesulfonamide, toluenesulfonamide) in soil has been developed. The target analytes were extracted from soil by a single low-pressurized microwave-assisted extraction (MAE) cycle (120°C, 10min) and quantified by high-performance liquid chromatography with UV detection. For all the seven analytes, quantitative extraction yields (72-119%, n=4) were observed from recovery tests on soil samples (1g) spiked with 5, 10 and 50mg kg(-1), using 4mL water-methanol (85:15) as extracting solution. For the lower concentrations levels (100, 250 and 500μg kg(-1)), the analytes were extracted from soil samples (2-3g) using 6mL methanol, and the extract was pre-concentrated by evaporation before analysis; recoveries in the range 70-117% were obtained (n=4). Suitable intra-day and inter-day precision were observed, with values of relative standard deviation generally below 6% and 11% (n=4), respectively. Linearity was evaluated in the concentration range 0.5-10mg L(-1) by matrix-matched standards, obtaining r(2)>0.9996. The experimental method quantification limit (MQL) was 100μg kg(-1). The entire procedure has been successfully applied to the analysis of real impacted soil samples.

This work presents the results obtained in using olive mill wastewater (OMW) as sacrificial agent for the photocatalytic H 2 evolution from water, at ambient temperature and pressure. The effects of irradiation time, catalyst amount, pH, and OMW concentration have been investigated. Under the best experimental conditions (4 h UV-A irradiation, 2 g L −1 Pt/TiO 2 , OMW 3.3% v/v, COD 944 mg L −1 , pH 3) up to 44 μmol H 2 were generated from aqueous samples. Consecutive irradiation cycles (4 × 4 h) on the same sample provided ca. 280 μmol H 2 , corresponding to 82% of the yield observed, under the same conditions and COD value, by using glucose as test sacrificial agent. H 2 evolution was strongly improved (+81%) by pre-treating OMW with magnesium silicate (125 g L −1 , 6 h contact), achieving a production of ca. 80 μmol H 2 by 4 h UV-A irradiation. The possibility to exploit sunlight in the photocatalytic process was gained by using Eosin Y/Pt/TiO 2 . Under solar light the H 2 yield resulted to be 66% with respect to that obtained by UV-A radiation. Beside some general mechanistic aspects of the photocatalytic process, benefits and drawbacks in recycling OMW for photocatalytic H 2 evolution from water have been highlighted.

Fluoroquinolone antibiotics (FQs) are important “emerging” micropollutants, and their environmental diffusion is an issue of great concern. In this study, the photochemical degradation of marbofloxacin (MAR) and enrofloxacin (ENR) adsorbed on montmorillonite (MMT) and kaolinite (KAO) clays was investigated. Being FQs photosensitive molecules, the sunlight-induced degradation of clay-adsorbed FQs and of their photoproducts was monitored as function of irradiation time. The photoproducts were identified by high performance liquid chromatography electrospray tandem mass spectrometry (HPLC-ESI-MS/MS) and the photochemical pathways have been elucidated. X-ray diffraction (XRD) has been employed to deeply study the solid-state photodegradation process of MAR and ENR on MMT. Interestingly, the XRD results clearly evidenced a significative variation of the interlayer spacing of MMT not only as function of FQs adsorbed amounts, but also in relationship with their photodegradation, not investigated by means of XRD as yet. The results confirmed that FQs adsorption is a bulk phenomenon that occurs in the interlayer spacing of the MMT structure; moreover, it was proved that sunlight largely degraded the adsorbed FQs, both on the external surface and in the interlayer spacing.

Pristine humic acids (HAs) were thermally condensed onto silica microparticles by a one-pot, inexpensive and green preparation route obtaining a mixed-mode sorbent (HA-C@silica) with good sorption affinity for glucocorticoids (GCs). The carbon-based material, characterized by various techniques, was indeed applied as the sorbent for fixed-bed solid-phase extraction of eight GCs from river water and wastewater treatment plant effluent, spiked at different concentration levels in the range 1–400 ng L−1. After sample extraction, the target analytes were simultaneously and quantitatively eluted in a single fraction of methanol, achieving enrichment factor 4000 and 1000 in river water and wastewater effluent, respectively. Full recovery for all compounds, was gained in the real matrices studied (80–125% in river water, 79–126% in wastewater effluent), with inter-day precision showing relative standard deviations (RSD) below 15% and 18% (n = 3), for river and wastewater effluent, correspondingly. The high enrichment factors coupled with high-performance liquid chromatography tandem mass spectrometry quantification (MRM mode) provided method quantification limits of 0.009–0.48 ng L−1 in river water and 0.06–3 ng L−1 in wastewater effluent and, at the same time, secure identification of the selected drugs. As also evidenced by comparison with literature, HA-C@silica proved to be a valid alternative to the current commercial sorbents, in terms of extraction capability, enrichment factor, ease of preparation and cost. The batch-to-batch reproducibility was assessed by recovery tests on three independently prepared HA-C@silica powders (RSD lower than 7%).

Adsorption and photocatalytic removal from water of marbofloxacin (MAR) and enrofloxacin (ENR), two fluoroquinolone (FQ) antibiotics widely present in surface waters, were investigated on zeolite Y derivatized with three different TiO2 catalysts (P25 Degussa and TiO2 obtained by optimization of a sol–gel method). The prepared materials were characterized by X-rays powder diffraction (XRPD), scanning electron microscopy (SEM), BET analysis and diffuse reflectance spectroscopy (DRS). TiO2-derivatization improved the adsorption capacities of zeolite Y for FQs and promoted the sunlight-induced degradation of FQs adsorbed (solid-state photodegradation), not investigated in literature yet. A large FQs removal (3 mg g−1) occurred in about 2 h (residual adsorbed FQs

This is the first-time reporting on the photocatalytic production of hydrogen gas (H2) via water splitting in the presence of swine sewage (SS) as sacrificial agent. H2 was evolved upon both UV-A and solar light irradiation in presence of platinised titania as the catalyst. The influences of irradiation time, catalyst amount, pH and SS concentration on the reaction yield were investigated. Under the best conditions, up to 50 μmol of H2 were produced from aqueous SS (1.7% v/v, COD 82 mg L−1), with good within-laboratory reproducibility (RSD

The adsorption of two veterinary fluoroquinolones, Enrofloxacin (ENR) and, for the first time, Marbofloxacin (MAR), was investigated on kaolinite and montmorillonite clays with the aim of evaluating the efficiency of these adsorbents in removing pharmaceuticals from soils and waters. Experiments were carried out at two different pHs in tap water and aqueous salt solution. Adsorption isotherms show that these drugs were adsorbed in remarkable amounts by the three materials examined (STx-1, SWy-1, kaolinite) with different mechanisms, as confirmed by XRD (X-ray diffraction) analysis. Different thermodynamic models have been applied and the best fit was obtained by means of Langmuir interactions models. In order to remove FQs from contaminated wastewaters, the three clays were contacted with water samples collected from ditches near cattle and swine farms obtaining a quantitative removal. The results proved that such minerals are suitable for the remediation of environmental matrices.

This paper presents an overview of the recent applications of molecularly imprinted polymers (MIPs) to sample preparation. The review is thought to cover analytical procedures for extraction of contaminants (mainly illegal/noxious organic compounds) from food and environmental matrices, with a particular focus on the various pre-concentration/cleanup techniques, that is offline and online solid-phase extraction (SPE), dispersive SPE (d-SPE), magnetic SPE (MSPE), solid-phase microextraction (SPME) and stir-bar sorptive extraction (SBSE), applied before instrumental quantification. The selectivity and extraction efficiency of MIP-based sorbent phases are critically discussed, also in relation to the physical-chemical properties resulting from the synthetic procedures. A variety of molecularly imprinted sorbents is presented, including hybrid composites embedding carbon nanomaterials and ionic liquids. The analytical performance of MIP materials in sample preparation is commented as function of the complexity of the matrix, and it is compared to that exhibited by (commercial) aspecific and/or immunosorbent phases.

In the present work, a new photocatalyst based on a new persistent luminescence phosphor, PeLM, and NPs- TiO2 was synthesized and the synthesis was optimized using a chemometric approach. A solid-state synthesis was used to obtain the persistent luminescence material while a sol-gel synthesis was used to obtain anatase NPs-TiO2. Each sample was then characterized by means of XRD, SEM and BET analysis, while the photocatalytic activity was evaluated testing the percent degradation of a methylene blue aqueous solution. Two different kinds of experiments were performed on the optimized sample, using a continuous irradiation or halving it with darkness cycles. It’s been demonstrated that the PeLM acts as an internal source for TiO2, providing the excitation required for the photocatalysis and so allowing to continue photon absorption even in darkness conditions. The two materials were coupled by means of a solid-state synthesis, varying the ratio between the reagents (1, 6), the heating temperature (350, 550°C) and time (1, 6 hours) through a chemometric approach, in order to find the optimized values. Validating the model led to the conclusion that the parameters affecting the synthesis have no significant interactions among them. The obtained results demonstrated the real applicability of this coupled system in the removal of Ofloxacin from water solution as probe of emerging organic pollutants.

This is the first report on the photodegradation of ofloxacin under simulated solar light and in actual environmental matrices in the presence of a g-C

The enhancement of the photocatalytic activity of TiO2 nanoparticles (NPs), synthesized in the presence of a very small amount of magnetite (Fe3O4) nanoparticles, is here presented and discussed. From X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses, the crystallinity of TiO2 nanoparticles (NPs) seems to be affected by Fe3O4, acting as nano-seeds to improve the tetragonal TiO2 anatase structure with respect to the amorphous one. Photocatalytic activity data, i.e., the degradation of methylene blue and the Ofloxacin fluoroquinolone emerging pollutant, give evidence that the increased crystalline structure of the NPs, even if correlated to a reduced surface to mass ratio (with respect to commercial TiO2 NPs), enhances the performance of this type of catalyst. The achievement of a relatively well-defined crystal structure at low temperatures (Tmax = 150 °C), preventing the sintering of the TiO2 NPs and, thus, preserving the high density of active sites, seems to be the keystone to understand the obtained results.

The analytical application of silica-supported graphitic carbon nitride (g-C 3 N 4 @silica) for solid-phase extraction (SPE) of fluoroquinolone (FQ) pollutants from water is presented for the first time. g-C 3 N 4 @silica was easily and quickly prepared by one-pot thermal condensation of dicyandiamide and characterized by powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and surface area measurements. The novel composite was applied as sorbent for SPE of FQs from water prior high-performance liquid chromatography with fluorescence detection. The extraction efficiency of g-C 3 N 4 was tested in tap and surface waters at actual concentrations (10–100 ng L −1 ). Quantitative adsorption was achieved using 100 mg sorbent (20 wt% g-C 3 N 4 ) for pre-concentration of 50–500 mL sample, at the native pH (∼7.5–8). Elution was performed with 25 mM H 3 PO 4 aqueous solution-acetonitrile (80:20), obtaining recoveries in the range 70–114%, enrichment factors up to 500 and inter-day RSDs ≤ 12%. The batch-to-batch reproducibility was assessed on three independently synthesized g-C 3 N 4 @silica preparations (RSD 6–12%). g-C 3 N 4 supported on silica microparticles proved to be of easy preparation, inexpensive, reusable for at least 4 extractions of raw surface waters, and suitable for determination in real matrices.

The widespread presence of fluoroquinolone antibiotics (FQs) in natural ecosystems is a health hazard for humans and other living organisms. The role of sunlight in degrading FQs present in environmental waters has been studied. In particular, the photodegradation of four largely employed FQs, viz. Ciprofloxacin (CIP), Danofloxacin (DAN), Levofloxacin (LEV) and Moxifloxacin (MOX) has been studied in not tampered river water. Degradation rates have been investigated at ppb levels (20–50 μg L−1) under solar light, and the results have been commented critically. The products distribution has been studied by HPLC-ESI-MS/MS analysis and structures have been attributed on the basis of their mass fragmentation spectra. Importantly from the environmental point of view, the (potentially toxic) FQ nucleus remained intact over the early stages of the degradation. Indeed, the photoproducts were proved to possess residual antibacterial activity, as shown from in vitro antibacterial activity tests against different well characterized human and environmental bacterial strains, carried out on the above FQs, as well as for Enrofloxacin (ENR) and Marbofloxacin (MAR).

Here we describe the extraction from soil of the major photo-transformation products (PTPs) of enrofloxacin (ENR) and danofloxacin (DAN), two fluoroquinolones (FQs) widely used in veterinary medicine and of growing environmental concern, because their PTPs have been shown to retain high antibacterial activity. The microwave-assisted extraction (MAE) technique developed previously for determination of FQs, and based on use of an alkaline aqueous solution of Mg(2+) as a complexing agent for the analytes, was applied to agricultural soil samples fortified with different amounts of the PTPs and residues of the parent compounds (53-1000 ng g(-1) for ENR, 24-148 ng g(-1) for DAN). The PTPs, obtained by irradiation of thin layers of the two drugs, were, after extraction, separated and quantified by HPLC-FD. Good recovery (70-130%) and precision (RSDs 1-6% for repeatability and 9-22% for reproducibility) were obtained by use of the overall analytical procedure. The method was applied for the first time to study the in-soil lifecycle of ENR and DAN PTPs, generated in the matrix by irradiation under natural sunlight, at environmentally significant concentrations. Results indicated that soil-adsorbed FQ PTPs are themselves liable to photodegradation and have lifetimes comparable with those of parent compounds.

The photodegradation of some among the most frequently prescribed fluoroquinolone antibacterials (FQs) was investigated in untreated river water under solar light as well as under the same conditions in the presence of suspended TiO2. The drugs considered included ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), levofloxacin (LEV), marbofloxacin (MAR) and moxifloxacin (MOX), the last two belonging to the most recent FQ generation. The experiments were carried out in lab-scale batch reactor at concentrations (20–50 μg L−1) comparable to those actually measured in surface waters, and the course of the reaction was monitored by high pressure liquid chromatography (HPLC) with fluorescence detector (FD). A first order kinetics was obeyed upon both direct photolysis and TiO2 heterogeneous photocatalysis. The photoproduced intermediates were identified by HPLC with electrospray ionization tandem mass spectrometry (ESI-MS/MS) and the degradation paths were identified. It was concluded that direct irradiation caused fluorine substitution and reductive elimination, while photocatalysis caused oxidative degradation of the amine side-chain (most efficient with tertiary amines and five-membered cyclic amines). The latter one was a minor process upon direct photolysis and involved hydrogen abstraction by excited states or photoproduced radicals. Photocatalytic decomposition occurred at a rate from two to five times faster than direct photolysis for all of the drugs, except for CIP, that is roughly proportional to the amine oxidation potential. The kinetic constants ranged from 0.061 to 0.66 min−1 in direct photolysis, from 0.22 to 2.78 min−1 in the presence of TiO2. In the latter process, a 90% abatement of the concentration of these otherwise highly persistent drugs was obtained in ca. 15 min. This supports the contention that TiO2 photocatalysis under solar light is a convenient and efficient method for the remediation of pollutants at the μg L−1 levels despite the presence of other non-target matrix constituents. Noteworthy, TiO2 side-chain photo-oxidation was equally effective in the further degradation of the primary intermediates at a rate comparable to that of the parent compounds. The degradation proceeded further so that it could be expected that the antimicrobial activity, related to the FQ quinolone core more than to the substituent pattern, could be effectively eliminated.