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In the present study, two novel molecularly imprinted polymers (MIPs) with remarkable recognition properties for metformin and its transformation product, guanylurea, have been prepared for their selective, enrichment, isolation and removal from aqueous media. The prepared adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and swelling experiments. The performance of the prepared MIPs was evaluated by various parameters including the influence of pH, contact time, temperature and initial compound concentration. The effects on the adsorption behavior of the removal process parameters were studied and the equilibrium data were fitted by the Langmuir and Freundlich models. Due to the imprinting effect, adsorption performance of MIPs was always superior to its corresponding NIP (non-imprinted polymer), with maximum adsorption capacity ∼80 mg g(-1) for both MIPs. Stability and reusability of the MIPs up to the 5th cycle meant that they could be applied repeatedly without losing substantial removal ability. In the next step, the prepared MIP nanoparticles were evaluated as sorbents in a dispersive solid phase extraction (D-SPE) configuration for selective enrichment and determination of metformin and guanylurea in different aqueous matrices. Under the working extraction conditions, the D-SPE method showed good linearity in the range of 50-1000 ng L(-1), repeatability of the extractions (RSD 2.1-5.1%, n=3), and low limits of detection (1.5-3.4 ng L(-1)). The expanded uncertainty of the data obtained was estimated following a bottom-up approach. The proposed method combined the advantages of MIPs and D-SPE, and it could become an alternative tool for analyzing the residues of METF and its transformation product GUA in complex water matrices, such as wastewaters., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In recent years, there has been a drive towards making pretreatment approaches more environmentally sustainable and eco-friendly, with the introduction of microextraction techniques, advanced materials, innovative solvents, automated setups, and technological advancements. In this context, there is a particular focus on the exploration and integration of new sorbents into microextraction techniques. Hydrogels, among the emerging materials, have garnered significant interest due to their unique features, including polymeric three-dimensional sorptive networks of hydrophilic chains, enhanced porosity, open-structure geometry, and valuable mechanical properties. They are amenable to various chemical modifications to acquire specific physicochemical properties and integrate advanced materials like carbon and magnetic nanoparticles, boosting their sorbent and application potential for diverse targets. Herein, the majority of demonstrated hydrogel-based sample preparation approaches for extracting organic analytes, coupled with liquid-chromatographic-(LC) or gas-chromatographic-(GC) methods, are presented, with a focus on the key role of the hydrogel and the environmentally-friendly characteristics of the methods. • Hydrogels are innovative porous materials with a high sorptive potential. • Hydrogels integrate improvements in novel materials and microextraction techniques. • All recent hydrogel-based extraction methods for organic compounds are presented. • Hydrogel-based methods are green, in particular when incorporating biopolymers. [ABSTRACT FROM AUTHOR]

Abstract: A monitoring study was carried out for the four seasons over 1-year monitoring period (March 2006–March 2007) to investigate the residues of 11 pharmaceuticals and personal care products (PPCPs) belonging to various therapeutic categories. The selected areas of the study were the municipal and hospital wastewater treatment plants (WWTPs) of Ioannina city, located in Western Greece. The most common pre-treatment technique for pharmaceuticals, solid-phase extraction (SPE), was used for the isolation and pre-concentration of the target analytes. The samples were screened using gas chromatography mass spectrometry (GC–MS). The results of the monitoring study, showed the occurrence of all target compounds in the wastewater samples. Concentrations in the municipal WWTP ranged between 0.3 and 164.4μg/L in the influent and between 0.5 and 13.9μg/L in the effluent. In the hospital WWTP concentrations ranged between 0.6 and 70.1μg/L in the influent and between 0.5 and 14.6μg/L in the effluent. Mean removal efficiencies ranged between 13% and 97% and between 9% and 87% for municipal and hospital WWTPs, respectively. Removal efficiencies were higher in the municipal WWTP than in the hospital WWTP. [Copyright &y& Elsevier]

Abstract: A simple and reliable sample methodology based on simultaneous ultrasonic extraction, sulfuric acid clean-up and headspace solid-phase microextraction (SPME)–gas chromatography–mass spectrometry has been developed as an advantageous analytical tool for the determination of seven polychlorinated biphenyl congeners in bird livers at low levels. The influence of several parameters on the efficiency of the proposed method was systematically investigated. The clean-up efficiency of sulfuric acid treatment was tested and compared with those of column chromatography (Flosiril, silica gel and alumina) and solid-phase extraction (SPE) (Supelclean ENVI-Carb cartridge) procedures. The use of sulfuric acid in the clean-up step prior to headspace solid-phase microextraction analysis allows the removal of interfering matrix compounds present in the liver extracts that would otherwise cause severe ionization suppression of the polychlorinated biphenyls (PCBs) during the ionization process. The optimized method had good linearity (R 2 >0.99) over the range studied (5–500ng/g wet weight) and showed satisfactory level of precision, with RSD values lower than 10.6%. The obtained relative recoveries ranged between 63 and 94%. The limits of detection (0.06–0.63ng/g wet weight) were low enough to check for harmful levels of polychlorinated biphenyls in biological samples, and were well below most of the restrictive limits established by European Union regulations. The method was found to be reliable under the operational conditions proposed and was applied successfully to the analysis of individual polychlorinated biphenyls in liver tissues. The results obtained from five bird species from Greece revealed the presence of the target compounds in all samples analyzed, at levels ranging between 0.54 and 39.45ng/g wet weight. [Copyright &y& Elsevier]

Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and selected ion monitoring (SIM) was used for the analytical determination of priority pesticide residues. Fibers coated with a 65-µm film thickness of polydimethylsiloxane divinylbenzene (PDMS-DVB) were used to extract 31 pesticides of different chemical groups. The quality parameters of the method demonstrated a good precision with detection limits of 1-56 ng/L. Linearity was controlled in the range of 0.1-50 µg/L. The proposed method was applied for the trace-level determination of the target pesticides in surface water samples including three rivers and one lake at the Epirus region (north-west Greece) for a period of one year. The results demonstrate the suitability of the SPME-GC-MS approach for the analysis of multi-residue pesticides in environmental water samples. [ABSTRACT FROM AUTHOR]

The partitioning behavior of organic biocides onto humic organic matter (Fluka humic acids) was investigated. Solid-phase microextraction (SPME) was used in both direct and headspace approaches to measure the freely dissolved proportion of the target analytes rather than the proportion bound to the polymer. Data obtained with direct and headspace modes are very similar. Results indicated that Irgarol 1051 had the strongest adsorption characteristics and was found to bind more strongly to humic acids than Sea Nine 211. Obtained values are in good agreement with previously reported data, showing that these biocides are transported mainly in the dissolved phase of marine waters. [ABSTRACT FROM AUTHOR]

A headspace solid-phase microextraction (HS-SPME) method in combination with GC–MS was used for the extraction and quantification of diazinon, fenitrothion, fenthion, parathion ethyl, bromophos methyl, bromophos ethyl and ethion. The method was developed using a 100-μm poly(dimethylsiloxane) fiber. The obtained results showed higher responses of the insecticides after addition of aliquots of water and solvent to the fruit samples. Calibration curves that were constructed for the analytes spiked into strawberry and cherry samples followed linear relationships with good correlation coefficients (R2>0.986). Linearity range was between 50 and 500 μg/kg and the precision was found to be lower than 15% when applying the optimized HS-SPME procedure to fruit samples. Limits of detection in both strawberry and cherry samples using GC–MS (selected ion monitoring mode) were below 13 μg/kg. Moreover, the HS-SPME method was applied to the analysis of fruit samples and compared with liquid–liquid extraction. Results obtained in this study were in good agreement with those obtained using liquid–liquid extraction demonstrating that the recommended procedure was a fast, accurate and stable sample pretreatment method obtaining good efficiency for the extraction of organophosporus insecticides from strawberries and cherries. [Copyright &y& Elsevier]

[Display omitted] • Comprehensive analysis of 10 OPFRs in two WWTPs in Thessaloniki. • Highest detection frequencies were calculated for TBEP, TCCP and TEP in influents and effluents. • All OPFRs exhibited low to moderate average removal efficiencies. • Mass loads indicated an increase in usage trends during spring. • All the compounds exhibited insignificant chronic risk to the three trophic levels. Exploring the occurrence pattern of organophosphate flame retardants (OPFRs) in environmental samples has attracted increasing attention lately. In the conventional wastewater treatment plants (WWTPs), OPFRs are not sufficiently removed and therefore are discharged to the aquatic environment. However, concerns arise from their release regarding the potential risk posed to organisms. Consequently, closely monitoring this group of emerging contaminants, along with the evaluation of the associated ecological risk are matters of utmost importance. Given the aforementioned information, influents and effluents from two WWTPs (WWTP-A and WWTP-S) in Thessaloniki were gathered during a 36-month sampling initiative spanning from 2020 to 2023 in order to evaluate the occurrence and concentration levels of OPFRs. The collected samples underwent solid-phase extraction and then preceded to analysis with a Q Exactive Focus Orbitrap mass analyzer. In the present study, except for the implementation of the target analysis approach, removal efficiencies and mass loads were further calculated. TBEP (tris-2-butoxyethylphosphate) and TEP (triethyl phosphate) were detected in all influent samples (%DF = 100 %) in WWTP-A while in WWTP-S only TCPP (tris-1-chloro-2-propyl phosphate) was omnipresent. In effluents of both WWTPs, only TEP maintained the same detection frequency (%DF = 100 %). The highest mean concentration levels in WWTP-S influents were calculated for TEP (327 ng/L) followed by TCPP (277 ng/L) while in WWTP-A the highest mean concentrations in influents were detected for TCPP (405 ng/L) and TDCP (Tris(1,3-dichloro-2-propyl)phosphate) (124 ng/L). In effluents, the highest mean concentration was reported for TCPP, in both WWTPs, reaching 295 ng/L and 240 ng/L in WWTP-S and WWTP-A respectively. Generally, OPFRs exhibited low to moderate average removal efficiencies. Positive and negative removal efficiencies were also noticed during the monitoring campaign. The average mass load in WWTP-S was as high as 10.1 mg/day/1000 inhabitants and in WWTP-A, 11 mg/day/1000 inhabitants in effluents. Finally, different mathematical tools were employed for the assessment of the risk posed to algae, invertebrates and fish. For the toxicity assessment in these three trophic levels the worst-case scenario was taken into consideration. Generally, all the target analytes presented low or medium values in all trophic levels for acute and chronic toxicity. [ABSTRACT FROM AUTHOR]

Olive fruit fly Dacus oleae is a well-known pest infecting the bark of olive fruit, leading to reduction of extracted olive oil properties. Among chemicals proposed for Dacus oleae population control, pheromone 1,7-dioxaspiro(5.5)undecane (DSU), Dacus pheromone, is considered as a promising agent, which is added in several traps. However, all proposed systems manage to sufficiently deliver DSU for only two weeks. Furthermore, an additional problem is the limited available amount of pheromone to use in such systems. To overcome this, in the present study, a novel synthetic procedure of DSU is described, including only five steps. Intermediate products were studied by High Resolution Mass Spectroscopy Electrospray Ionization (HRMS-ESI) (m/z), while the resulting DSU was further characterized by 1H and 13C-NMR. Synthesized DSU was further encapsulated in poly(L-lactic acid) (PLLA) microparticles in three different concentrations; 5, 10 and 20% w/w. Its successful incorporation was studied by FT-IR, XRD and differential scanning calorimeter (DSC) while two procedures, liquid extraction and solid phase microextraction, followed by GC-MS analysis, was used for quantification of pheromone to microparticles. It was found that microparticles loading was over 85% for all three formulations. Its release showed a prolonged profile for microparticles containing 20% w/w DSU, lasting four weeks, while the quantity of DSU released reached 100%. These microparticles could be appropriate to control Dacus oleae population. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molecularly imprinted polymers (MIPs) synthesized using penconazole as template molecule and N-Isopropylacrylamide (NIPAM) as functional monomer show good recognition properties toward the triazole ring. • Widely employed triazole pesticides can be efficiently isolated from complex matrices (i.e. juices, surface water) by the strategy of dispersive solid phase extraction using the developed MIPs as selective sorbents (MIP-d-SPE). • Plackett-Burman design of experiment is a useful tool to screen the effect of different combinations of functional monomers and cross linkers as well as the effect of different extraction conditions. In the present study, novel molecularly imprinted polymers were prepared using penconazole as template and different combinations of functional monomers (acrylic acid (AA) and N-isopropylacrylamide (NIPAM)) and cross-linkers (ethylene glycol dimethacrylate (EGDMA) and trimethylolpropane trimethacrylate (TRIM)), according to a Plackett-Burman design of experiments. Materials were fully characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and nitrogen adsorption analysis. Rebinding behaviors in solution were studied both at the equilibrium (Langmuir, Freundlich and Temkin models), and at the non-equilibrium (pseudo-first, pseudo-second order kinetics). Materials were further tested as sorbents for dispersive solid phase extraction (d-SPE) on apple juice for multicomponent recovery of triazole fungicides at trace level, testing several variations of extraction parameters (juice pH, amount of sorbent, adsorption time, desorption solvent, desorption time) leading to the selection of the best materials and simultaneously of the best extraction conditions. MIPs synthesized with NIPAM showed significatively higher affinity for triazole pesticides in apple juice than the ones synthesized with AA, while no differences emerged for the two cross-linkers employed (EGDMA, TRIM). Selectivity was also assessed, testing MIPs as d-SPE sorbents in undiluted apple juice spiked with triazole pesticides concurrently with other interfering compounds. The newly developed NIPAM-based penconazole-imprinted MIPs showed an excellent recognition mechanism towards compounds containing the triazole ring, and significatively lower recoveries for other compounds. The developed analytical procedure based on molecularly imprinted polymer dispersive solid phase extraction and liquid chromatography coupled with mass spectrometry (MIP-d-SPE-LC-MS) was validated for selective enrichment and determination of triazole compounds in apple juice samples and river water samples with good recoveries (94.67%–109.03% for river water, 89.79%–110.23%, for apple juice), high repeatability (RSD% < 3.97 for river water, RSD% < 4.85 for apple juice), and reproducibility (RSD% < 5.95 for river water and RSD% < 7.14 for apple juice). [ABSTRACT FROM AUTHOR]

In the present study, a molecularly imprinted solid-phase microextraction fiber (MIP-SPME f ) was synthesized and applied for the selective removal and extraction of the antiviral drug, abacavir (ABA). Morphology and structure characterization of fibers were performed by scanning electron microscopy and Fourier transform infrared spectra, respectively. The effects on the adsorption behavior of the process parameters were studied and the equilibrium data were fitted by the Langmuir, Freundlich and Langmuir-Freundlich models. The maximum adsorption capability (Q max ) was determined by Langmuir- Freundlich model and was 149 mg/g for MIP-SPME f . In the next step, SPME methodology followed by liquid desorption and liquid chromatography with mass spectrometry (LC/MS) has been developed and evaluated for the determination of the target compound in environmental and biological matrices (surface waters, wastewaters and urine). Parameters that could influence SPME efficiency were investigated. Then, optimization of stirring speed, extraction time and salt content was carried out by using a central composite design (CCD) and response surface methodology (RSM). A quadratic model between dependent and independent variables was built. Under the optimum conditions (extraction time 40 min, stirring rate 650 rpm and salt content 0.3% NaCl w/v) the validated method presented a high sensitivity and selectivity with LODs and LOQs in the range of 10.1–13.6 and 33.3–43.9 ng/L, respectively. The developed method was successfully applied to the analysis of ABA in real samples. The percentage extraction efficiency ranged from 88 to 99% revealing good accuracy and absence of matrix effects. [ABSTRACT FROM AUTHOR]

[Display omitted] • HRMS-based target/suspect analysis workflow for PFAS in 5 environmental matrices. • Data-dependent 'discovery' acquisition enabled the unequivocal identification of suspect PFAS. • Method quantification limits reached the pg L−1 scale for L-PFBS, L-PFHpS, L-PFNS, L-PFDS. • Suspect screening workflow enabled matching scores > 80% with the data-dependent Discovery Mode. • PFOS was found 1.5 ng L−1 in tap water, 394.4 ng L−1 in effluents. Per- and polyfluoroalkyl substances (PFASs) are a man-made diverse group of highly fluorinated aliphatic molecules, entailing risks to the ecosystems and human health. Herein, a streamlined, single-shot, HRMS-based analytical workflow for the quantitation and suspect screening of various PFAS was developed. Sample preparation was based on weak-anion exchange solid phase extraction, while instrumental analysis was performed by highly sensitive liquid chromatography Orbitrap–high-resolution mass spectrometry. The target method was optimized and validated for drinking water, surface water, and wastewater, while it was also modified to be efficient for leachates. Method performance was excellent in terms of linearity (R2 > 0.99), detection/quantification limits (reaching even at pg L−1 scale), recoveries (70–108 %, for most of the compounds), and precision (<20%). Isotopically labelled internal standards and matrix-matched calibration curves were used for quantification. The suspect analysis performed on a single-stage HRMS method operating in data-dependent 'discovery' mode. Thus, content-rich spectra were acquired and once combined with suspect screening features such as peak picking, feature alignment, and compound annotation enabled the putative annotation of the tested PFAS with high confidence. After evaluation, the presented fully elaborated workflow was applied to real samples to explore the putative annotation of the tested PFAS with high confidence for the first time in Greece for five different matrices, revealing maximum concentrations for PFOS 1.5 ng L−1 in tap water and 394.4 ng L−1 in effluent wastewater, and PFHxA 4284.8 ng L−1 in leachates. [ABSTRACT FROM AUTHOR]