Determination of hexavalent chromium in textiles of daily use by ion chromatography and dermal risk assessment.

The determination of hexavalent chromium in textiles and clothes is challenging since during extraction, the original oxidation state should not be altered. Since, as a matter of fact, current analytical methods are focused only on total chromium determination, the purpose of this research is to develop a reliable analytical method for the determination of Cr(VI) in textiles and tissues of daily use for a reliable application of risk analysis models, which are usually based on total Cr data. After optimization, a 0.0025 M Na3PO4 extraction solution was selected for the extraction of Cr(VI) from textiles. This solution minimizes possible interconversion redox reactions and interference, and provides good extraction recoveries (88.4 ± 2.5% - 105.5 ± 0.6 %, according to Cr(VI) concentration) and quantitation limits (0.017 mg/kg), fully complying the current limits set for Cr(VI) in textiles in contact with skin, and for leachable Cr(VI). The developed method was validated investigating intra-day repeatability (n = 10) and inter-day repeatability (n = 30) which were below 12%, and matrix effect which was below 6% confirming the precision of the method and the negligibility of a matrix interference during the whole analysis. The method, which was proved to be suited also for bioaccessibility studies in saliva and sweat, was applied to the analysis of tank top, coloured paper napkin, polyamide tights, panties, highlighting Cr(VI) content in the panties only at very low concentration (0.028 mg/kg). As verified by ECHA and US EPA approaches, this amount does not pose a non-carcinogenic risk for human health. As regards carcinogenic risk, considering both adult and child exposure, the dermal contact with the panties poses an acceptable risk (R ≤ 10-6).

Feasibility of a Heterogeneous Nanoscale Zero-Valent Iron Fenton-like Process for the Removal of Glyphosate from Water.

Glyphosate is a widely used herbicide, and it is an important environmental pollutant that can have adverse effects on human health. Therefore, remediation and reclamation of contaminated streams and aqueous environments polluted by glyphosate is currently a worldwide priority. Here, we show that the heterogeneous nZVI-Fenton process (nZVI + H2O2; nZVI: nanoscale zero-valent iron) can achieve the effective removal of glyphosate under different operational conditions. Removal of glyphosate can also take place in the presence of excess nZVI, without H2O2, but the high amount of nZVI needed to remove glyphosate from water matrices on its own would make the process very costly. Glyphosate removal via nZVI--Fenton was investigated in the pH range of 3-6, with different H2O2 concentrations and nZVI loadings. We observed significant removal of glyphosate at pH values of 3 and 4; however, due to a loss in efficiency of Fenton systems with increasing pH values, glyphosate removal was no longer effective at pH values of 5 or 6. Glyphosate removal also occurred at pH values of 3 and 4 in tap water, despite the occurrence of several potentially interfering inorganic ions. Relatively low reagent costs, a limited increase in water conductivity (mostly due to pH adjustments before and after treatment), and low iron leaching make nZVI-Fenton treatment at pH 4 a promising technique for eliminating glyphosate from environmental aqueous matrices.

Microwave-assisted extraction and gas chromatographic determination of thirty priority micropollutants in biowaste fraction derived from municipal solid waste for material recovery in the circular-economy approach.

European and national waste directives prioritize recycling of wastes, as well as material and energy recovery from wastes themselves. Bio-waste fraction can be converted into new resources whose quality is strictly dependent upon that of waste feedstock. Methods to evaluate the contamination from organic micropollutants in bio-waste are rarely investigated. The aim of this work was to develop an innovative analytical method for the extraction and quantification of 16 polycyclic aromatic hydrocarbons (PAHs) and 14 polychlorinated biphenyls (PCBs, including dioxin-like compounds) in bio-waste. Through a full-factorial experimental design, a microwave-assisted extraction technique was optimized to extract the thirty targeted micropollutants, studying the effect of cyclohexane and dichloromethane as extraction solvents with or without acetone, and of extraction temperature. Purification of the extract was obtained by a silica-based solid-phase extraction cartridge, followed by a sulfuric acid treatment. The analysis was carried out by gas chromatography coupled with mass spectrometry. The optimized method, validated directly in the bio-waste matrix fortified with isotopically marked surrogates, is characterized by good extraction recoveries, included within 47 and 106% (relative standard deviations <10%), by satisfactory intra-day (<1.1%) and inter-day (<9.3%) precision, and by low matrix effect (<17%), despite the complexity of the matrix. The optimized procedure, applied to the analysis of PAHs and PCBs in a bio-waste sample collected from a local anaerobic digestion and composting plant, showed a total PAHs content of 562 µg/kg. As regards PCBs, the dioxin-like congener PCB 118 was the only compound quantified (25 ± 6 µg kg-1).

Biochars intended for water filtration: A comparative study with activated carbons of their physicochemical properties and removal efficiency towards neutral and anionic organic pollutants.

Seven biochars (BCs) obtained from pyrolysis or gasification of different vegetal feedstocks were thoroughly characterized in comparison with three commercial activated carbons (ACs) routinely used in drinking water treatment plants. BCs and ACs characterization included the determinations of ash, iodine and methylene blue adsorption indexes, and the release of metals and polycyclic aromatic hydrocarbons, which were performed according to international standards applied for adsorption media to be used in drinking waters. Total specific surface area, micropore and mesopore specific surface area, pH of the point of zero charge, and the release of polychlorinated biphenyls were also determined in all chars. Principal component analysis and cluster analysis were performed in order to summarize the complex set of information deriving from the aforementioned characterizations, highlighting the BC most similar (BC6 from high temperature gasification of woody biomass) and most different (BC7 from low-temperature pyrolysis of corn cob) from ACs. These BCs were studied for their adsorption in ultrapure water towards diiodoacetic acid (an emergent disinfection by-product), benzene, and 1.2-dichlorobenzene, in comparison with ACs, and results obtained were fitted by linearized Freundlich equation. Overall, BC6 showed higher sorption performances compared to BC7, even though both BCs were less performing sorbents than ACs. However, the sorption properties of BCs were maintained also in real water samples collected from drinking water treatment plants.

A Review on the Degradation of Pollutants by Fenton-Like Systems Based on Zero-Valent Iron and Persulfate: Effects of Reduction Potentials, pH, and Anions Occurring in Waste Waters.

Among the advanced oxidation processes (AOPs), the Fenton reaction has attracted much attention in recent years for the treatment of water and wastewater. This review provides insight into a particular variant of the process, where soluble Fe(II) salts are replaced by zero-valent iron (ZVI), and hydrogen peroxide (H2O2) is replaced by persulfate (S2O82-). Heterogeneous Fenton with ZVI has the advantage of minimizing a major problem found with homogeneous Fenton. Indeed, the precipitation of Fe(III) at pH > 4 interferes with the recycling of Fe species and inhibits oxidation in homogeneous Fenton; in contrast, suspended ZVI as iron source is less sensitive to the increase of pH. Moreover, persulfate favors the production of sulfate radicals (SO4•-) that are more selective towards pollutant degradation, compared to the hydroxyl radicals (•OH) produced in classic, H2O2-based Fenton. Higher selectivity means that degradation of SO4•--reactive contaminants is less affected by interfering agents typically found in wastewater; however, the ability of SO4•- to oxidize H2O/OH- to •OH makes it difficult to obtain conditions where SO4•- is the only reactive species. Research results have shown that ZVI-Fenton with persulfate works best at acidic pH, but it is often possible to get reasonable degradation at pH values that are not too far from neutrality. Moreover, inorganic ions that are very common in water and wastewater (Cl-, HCO3-, CO32-, NO3-, NO2-) can sometimes inhibit degradation by scavenging SO4•- and/or •OH, but in other cases they even enhance the process. Therefore, ZVI-Fenton with persulfate might perform unexpectedly well in some saline waters, although the possible formation of harmful by-products upon oxidation of the anions cannot be ruled out.

Characterization Techniques as Supporting Tools for the Interpretation of Biochar Adsorption Efficiency in Water Treatment: A Critical Review.

Over the past decade, biochar (BC) has received significant attention in many environmental applications, including water purification, since it is available as a low-cost by-product of the energetic valorisation of biomass. Biochar has many intrinsic characteristics, including its porous structure, which is similar to that of activated carbon (AC), which is the most widely used sorbent in water treatment. The physicochemical and performance characteristics of BCs are usually non-homogenously investigated, with several studies only evaluating limited parameters, depending on the individual perspective of the author. Within this review, we have taken an innovative approach to critically survey the methodologies that are generally used to characterize BCs and ACs to propose a comprehensive and ready-to-use database of protocols. Discussion about the parameters of chars that are usually correlated with adsorption performance in water purification is proposed, and we will also consider the physicochemical properties of pollutants (i.e., Kow). Uniquely, an adsorption efficiency index BC/AC is presented and discussed, which is accompanied by an economic perspective. According to our survey, non-homogeneous characterization approaches limit the understanding of the correlations between the pollutants to be removed and the physicochemical features of BCs. Moreover, the investigations of BC as an adsorption medium necessitate dedicated parallel studies to compare BC characteristics and performances with those of ACs.

Amino groups modified SBA-15 for dispersive-solid phase extraction in the analysis of micropollutants by QuEchERS approach.

In the analysis of contaminants in food products, sample preparation is performed by proper adsorbents, whose choice is crucial to eliminate matrix interference. In this work we modified SBA-15 adsorbents by functionalization with (3-aminopropyl)-triethoxysilane (SBA-15-APTES) and N-[3-(trimethoxysilyl)propyl]aniline (SBA-15-AN) aiming to use them for the first time in the clean-up step of a QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction of micropollutants from strawberry, a sugar rich fruit. After physico-chemical characterization by nitrogen adsorption, infrared spectroscopy and thermogravimetric analysis, the adsorption capabilities of SBA-15 sorbents and possible interaction mechanisms were studied at different pH (2.1-8.5) for glucose, sucrose and fructose at concentrations characteristic of those found in strawberries. The performance of the two SBA-15 sorbents was compared with that of commercial PSA (primary secondary amine), usually proposed in QuEChERS protocols. Both SBA-15 materials exhibit up to 30% higher adsorption than PSA, suggesting their possible QuEChERS application. Synthesized SBA-15 adsorbents were hence used as innovative dispersive sorbents in the QuEChERS extractions of 13 PAHs and 14 PCBs from strawberry. For PCBs, SBA-15-AN provides better matrix removal than PSA and comparable extraction recoveries around 90%. For PAHs, the use of SBA-15-AN has the advantage of lower relative standard deviation (7%) than PSA (19%).

Extraction of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls from Urban and Olive Mill Wastewaters Intended for Reuse in Agricultural Irrigation.

BACKGROUND: Domestic and industrial wastewater can be introduced in a reuse chain for irrigation purposes. OBJECTIVE: In this paper, we developed analytical procedures for the extraction of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) along a wastewater reuse chain for irrigation purposes. Besides urban wastewaters, olive mill wastewater (OMWW) was considered as a potential water source. Wastewaters were purified by different treatments (urban wastewater plants, pilot-activated sludge, and constructed wetland) and used for the irrigation of olive trees. Suitable extraction procedures were used to analyze treated and untreated wastewaters, soils, and postirrigation leachates. RESULTS: For wastewater and leachate samples, the optimized reverse-phase solid-phase extraction (SPE) provided recoveries up to 79%. For OMWW, the SPE procedure was preceded by a normal-phase purification stage with silica gel for the removal of polyphenols, which were as high as 8.7 g/L. After optimization, extraction recoveries in blank solutions were in the range 20-67% and moderately reduced (10-38%) in OMWW as a result of the matrix effect (ME; -10/-60%) ascribed to the very high value of chemical oxygen demand (264 g/L). LODs of the method were below 1.1 µg/L (PAHs) and 3.2 µg/L (PCBs) using GC-MS analysis. For soil samples of different compositions, microwave-assisted extraction (MAE) provided better extraction recoveries and reproducibility than the more common quick, easy, cheap, effective, rugged, and safe approach, which was affected by a high ME. The LODs of the MAE/GC-MS method were below 4.9 µg/kg (PAHs) and 12.3 µg/kg (PCBs). CONCLUSIONS: The analytical procedures developed are a valuable tool to quantify the possible propagation of residual contamination from PAHs/PCBs with irrigation along the wastewater reuse chain.

Towards the revision of the drinking water directive 98/83/EC. Development of a direct injection ion chromatographic-tandem mass spectrometric method for the monitoring of fifteen common and emerging disinfection by-products along the drinking water supply chain.

According to the recent proposal released by the European Commission for the revision of the 98/83/EC Directive, water suppliers will be requested to monitor the nine bromine- and chlorine congeners of haloacetic acids, HAAs, as well as the oxyhalides chlorite and chlorate, as disinfection by-products (DBPs) originated during the potabilization process. In this work, we propose a direct-injection method based on ion chromatography and mass spectrometric detection for the determination of the mentioned DBPs as well as bromate (already included in the 98/83/EC), implemented also for the following emerging HAAs monoiodo-, chloroiodo- and diiodo-acetic acids. The method was optimized to include the fifteen compounds in the same analytical run, tuning the chromatographic (column and gradient) and detection conditions (suppression current, transitions, RF lens settings and collision energies). To avoid matrix effect and to manage the instrumental conditions, optimization was performed directly in drinking water matrix. The method quantitation limits satisfy the new limits imposed by the future directive and range from 0.08 µg/L (monobromoacetic acid) to 0.34 µg/L (trichloroacetic acid). The performance of the method was checked along different strategic sampling points of three potabilization plants serving the city of Turin (Italy), including intermediate treatments and finished waters. Recovery was checked according to the ±30% limit of acceptability set by EPA regulations. The effect of disproportionate concentrations of chlorite and chlorate in respect to HAAs on HAA signals was studied; this aspect is underestimated in literature. The method is routinely applied by the potabilization plant of the city of Turin to confirm the effectiveness of all control measures in abstraction, treatment, distribution and storage. This study represents the first example in Italy of development and use of a cutting-edge technique for HAAs analysis along the potabilization processes.

Chromatographic determination of biogenic amines in four typical Italian cheeses: correlations with processing and nutritional characteristics through a chemometric approach.

BACKGROUND: The presence of biogenic amines (BAs) fermented food is well known. They may affect food quality, posing health risks. In this work, four typical Italian cheeses, exported worldwide, were analyzed to determine the possible presence of BAs. The cheese samples were analyzed untreated and having been subjected to common or incorrect consumer handling (domestic grating, unrefrigerated storage). RESULTS: A chromatographic-amperometric method was developed and validated. Extraction of BAs was performed by the addition of eluent, determining matrix effect and recovery of biogenic amines directly within the cheeses. Biogenic amines were present in the range of 0.019-0.044 g kg-1 , well below the current EU limit. Home-manipulation confirmed recontamination of the cheese. The contents of BAs were correlated with the main processing parameters and with the nutritional properties of the four cheeses through the multivariate statistical analysis (principal component analysis). This is believed to be the first study that presents these correlations. CONCLUSION: This study highlights correlations among BAs and carbohydrates, and anticorrelations with pH and, to a lesser extent, with moisture. Interestingly, BAs are correlated with fat content. This correlation was confirmed by a new principal component analysis performed on our data set with additional data from the literature. © 2019 Society of Chemical Industry.

Regenerable, innovative porous silicon-based polymer-derived ceramics for removal of methylene blue and rhodamine B from textile and environmental waters.

The presence of residual color in treated textile wastewater above the regulation limits is still a critical issue in many textile districts. Innovative, polymer-derived ceramics of the Si-C-O system were here synthesized in order to obtain porous nanocomposite materials where a free carbon phase is dispersed into a silicon carbide/silicon oxycarbide network. The sorbents were comprehensively characterized for the removal of two model water-soluble dyes (i.e., the cation methylene blue and the zwitterion rhodamine B). Adsorption is very rapid and controlled by intra-particle and/or film diffusion, depending on dye concentration. Among the nanocomposites studied, the SiOC aerogel (total capacity about 45 mg/g, is easily regenerated under mild treatment (250 °C, 2 h). Adsorption of dyes is not affected by the matrix composition: removals of 150 mg/L methylene blue from river water and simulated textile wastewater with high content of metal ions (2-50 mg/L) and chemical oxygen demand (800 mg/L) were higher than 92% and quantitative for a dye concentration of 1 mg/L.

Determination of phthalate diesters and monoesters in human milk and infant formula by fat extraction, size-exclusion chromatography clean-up and gas chromatography-mass spectrometry detection.

A sensitive and reliable analytical method was developed for the simultaneous determination of five phthalate diesters and corresponding monoesters in human milk samples and infant formulas. The method involved a liquid-liquid extraction with a CH2Cl2/CH3OH/NaCl 30% 2/1/0.5 (v/v/v) mixture, the clean-up of the extract by size-exclusion chromatography (swelling and elution solvent: cyclohexane/ethyl acetate 9/1v/v), the derivatization of monoesters by trimethylsilyl-diazomethane and instrumental analysis by gas chromatography coupled with mass spectrometry. Recovery was in the range of 83-115% and precision was found between 9% and 21%. For phthalate diesters, method detection limits (MDLs) ranged from hundreds of ng/kg to 4.2µg/kg on a fresh weight milk (f.w.) basis, depending on blank contribution evaluated in matrix. Lower MDLs (0.03-0.8µg/kg f.w.) were achieved for corresponding monoesters. The proposed method was applied to the determination of target compounds in nine human milk samples and four infant formulas, confirming their presence in all samples. However, a generally higher contamination was assessed in artificial milk than in breast milk samples.

Chromium, nickel, and cobalt in cosmetic matrices: an integrated bioanalytical characterization through total content, bioaccessibility, and Cr(III)/Cr(VI) speciation.

The presence of certain metals naturally contained inside raw materials (e.g., pigments) used to produce cosmetics for make-up may represent a serious concern for the final quality and safety of the product. The knowledge of the total concentration of metals is not sufficient to predict their reactivity and their toxicological profile. For these reasons, we set up a comprehensive approach to characterize the content of Co, Cr, and Ni in two raw materials for cosmetic production, a black iron oxide and a pearly pigment, and in a finished product, pearly powder eye shadow. Namely, besides the total metal concentrations, the speciation of chromium and the bioaccessibility of the three metals were assessed. Since no standard method is so far available for hexavalent chromium extraction from cosmetic samples, three approaches were compared (EPA 3060A method, IRSA 16 method, and a Na3PO4 extraction). Results show that Na3PO4 extraction is the most selective one. Cr(VI) was undetectable in black iron oxide and present at very low concentrations (about 0.3 mg/kg) in pearly pigment and in the pearly powder eye shadow samples. The extracted Cr(VI) concentrations are not related to the total Cr content in the samples. Bioaccessibility studies were performed by in vitro extractions with synthetic lacrimal fluids and sweat. Despite the wide range of metal concentrations in the samples, the amounts of bioaccessible elements were undetectable or very low (less than 0.4 mg/kg), thus suggesting that metals in the three samples are present in inert forms. Graphical abstract The possible leaching of metals from cosmetics to biological fluids. Spectroscopic and chromatographic techniques provide complementary information for an integrated bioanalytical approach to risk characterization.

New approaches for extraction and determination of betaine from Beta vulgaris samples by hydrophilic interaction liquid chromatography-tandem mass spectrometry.

Betaine is one of most studied biologically active compounds, due its role in the main biological processes. Although it may be found in several plants and roots, such as the Beta vulgaris family, present in typical diets, just a few analytical methods have been developed for its extraction from roots. A new, quick and effective procedure for the isolation and determination of betaine from two different varieties of B. vulgaris (red and gold) is presented. For betaine extraction, an accelerated solvent extraction (ASE) was coupled with solid-phase extraction. For betaine determination, a separation method based on hydrophilic interaction chromatography coupled with tandem mass spectrometry was optimized for a sensible detection of betaine by means of experimental design. Recoveries were about 93%, with RSD <5%, for both the matrices, without evidence of interfering species. The total content of betaine in extracts of various parts of plants (juice, peel, root) have been determined, obtaining concentrations in the range 3000-4000 mg/L for the juice and in the range 2-5 mg/g for the pulp and for the peel. The B. vulgaris gold species exhibited a higher concentration of betaine, compared to the red variety. Additionally, a micro extraction by packed sorbent technique and a modified quick, easy, cheap, rugged and safe (QuEChERS) procedure, were also tested and compared. Despite the lower recoveries of the latter, with respect to the ASE/SPE procedure (75-89%, RSD <1.5%), the ease of the method, which can be applied without the SPE purification procedure, can represent a positive improvement. Graphical abstract Determination of betaine from Beta vulgaris samples.

Functionalized iron oxide/SBA-15 sorbent: investigation of adsorption performance towards glyphosate herbicide.

Glyphosate is a worldwide-used herbicide occurring in many monitoring campaigns. Efficient technologies are currently unavailable for glyphosate removal from waters. In this work, a SBA-15 mesoporous silica-based material (Fe-NH2-SBA-15) was synthesized and studied for the adsorption of glyphosate from waters. In order to promote specific interactions between the sorbent and glyphosate via phosphoric group, iron oxide nanoparticles were encapsulated and a surface functionalization with (3-aminopropyl)triethoxysilane was accomplished. The adsorption of glyphosate on Fe-NH2-SBA-15 was investigated as a function of (i) pH, (ii) ionic strength (I), and (iii) adsorbate to adsorbent ratio (C), using a two-level, three-factor experimental design. The experimental design allowed for understanding the effect of the abovementioned variables and for proposing experimental conditions for quantitative removal (pH = 2.1, I = 1⋅10-2 M and C = 0.35) under both batch and dynamic conditions. Interaction mechanism between glyphosate and Fe-NH2-SBA-15 sorbent was elucidated by studying the adsorption behavior of sorbents derived from the intermediate stages of synthesis and by desorption tests. Fe-NH2-SBA-15 sorbent can be quantitatively regenerated by 12.5 mM NaOH, and can be reused at least for five adsorption/desorption cycles. Quantitative removal of glyphosate from inlet and effluent wastewaters from a wastewater treatment plant is shown.

Simultaneous determination of five common additives in insulating mineral oils by high-performance liquid chromatography with ultraviolet and coulometric detection.

Dielectric mineral oils are used to impregnate power transformers and large electrical apparatus, acting as both liquid insulation and heat dissipation media. Antioxidants and passivators are frequently added to mineral oils to enhance oxidation stability and reduce the electrostatic charging tendency, respectively. Since existing standard test methods only allow analysis of individual additives, new approaches are needed for the detection of mixtures. For the first time we investigate and discuss the performance of analytical methods, which require or do not require extraction as sample pretreatment, for the simultaneous reversed-phase high-performance liquid chromatography determination of passivators (benzotriazole, Irgamet(®) 39) and antioxidants (N-phenyl-1-naphtylamine, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol), chosen for their presence in marketed oils. Quick easy, cheap, effective, rugged and safe and solid phase extractions were evaluated as sample pretreatments. Direct sample-injection was also studied. Ultraviolet spectrophotometry and direct-current coulometry detection were explored. As less prone to additive concentrations variability, the direct-injection high-performance liquid chromatography with ultraviolet and coulometric detection method was validated through comparison with Standard Method IEC 60666 and through an ASTM interlaboratory proficiency test. Obtained detection limits are (mg kg(-1) ): benzotriazole (2.8), Irgamet(®) 39 (13.8), N-phenyl-1-naphtylamine (11.9), 2,6-di-tert-butylphenol (13.1), 2,6-di-tert-butyl-p-cresol (10.2). Simultaneous determination of selected additives was possible both in unused and used oils, with good precision and accuracy.

Fully automated on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry for the simultaneous analysis of alkylphenol polyethoxylates and their carboxylic and phenolic metabolites in wastewater samples.

Three different sorbents (i.e. endcapped octadecylsilane, octasilane and styrene-N-vinylpiperidinone co-polymer) were investigated in order to develop an on-line solid phase extraction-liquid chromatographic tandem mass spectrometric method (on-line SPE-LC-MS/MS) for the simultaneous analysis of alkylphenols polyethoxylate (AP(n)EOs, n = 1-8) and corresponding monocarboxylate (AP1ECs) and phenolic (APs) metabolites. The endcapped octadecylsilane was selected due to its full compatibility with a chromatographic approach, which allowed the elution of positively and negatively ionisable compounds in two distinct retention time windows, using a water-acetonitrile-tetrahydrofuran ternary gradient and a pellicular pentafluorophenyl column. On this SPE sorbent, the composition of the loading/clean-up solution was then optimized in order to achieve the best recoveries of target analytes. Under the best experimental conditions, the total analysis time per sample was 25 min and method detection limits (MDLs) were in the sub-nanograms per litre to nanograms per litre range (0.0081-1.0 ng L(-1)) for AP(n)EOs with n = 2-8, AP1ECs and APs, whereas for AP1EOs, an MDL of about 50 ng L(-1) was found. Using the mass-labelled compound spiking technique, the method performance was tested on inlet and outlet wastewater samples from three activated sludge treatment plants managing domestic and industrial sewages of the urban areas and the textile district of Prato and Bisenzio valley (Tuscany, Italy); in most cases, apparent recovery percentages approximately in the ranges of 50-110% and 80-120% were found for inlet and outlet samples, respectively. The on-line SPE-LC-MS/MS analysis of wastewater samples highlighted the presence of target analytes at concentrations ranging from few nanograms per litre to thousands nanograms per litre, depending on the compound and matrix analysed. AP2ECs were also tentatively identified in outlet samples.

Evaluation of different QuEChERS procedures for the recovery of selected drugs and herbicides from soil using LC coupled with UV and pulsed amperometry for their detection.

Seven quick, easy, cheap, effective, rugged and safe (QuEChERS)-based procedures, differing in both the extraction and clean-up steps, were investigated for the recovery of bentazone (BTZ), atrazine (ATZ), carbamazepine (CBZ), phenytoin (PNT) and its metabolite 5-(p-hydroxyphenyl-),5-phenylhydantoin (HPPH) from soil. Target analytes were chosen for their extensive use and/or occurrence in soil, as well as for their medium-high polarity characteristics (log K OW values in the range 0.88-2.80), which have been reported as a critical parameter for the recovery from soil with QuEChERS approaches. Liquid chromatography coupled with UV and pulsed amperometric (PA) detection at a glassy carbon electrode was used as instrumental technique. The recovery data obtained within each tested procedure were discussed for each compound investigated, highlighting different behaviour depending on the specific physicochemical characteristics of the analytes. The optimized QuEChERS conditions consisted of the extraction of analytes with CH3CN:H2O 70:30, 5 % CH3COOH, followed by a dispersive solid-phase extraction (d-SPE) clean-up step with C18 sorbent. This method, in which water is directly added to the soil together with acetonitrile and salts, allowed the rehydration step to be avoided, which can be as long as 30 min. Matrix effects were evaluated for both the detection techniques at different concentration levels, and they were below 24 % for both the detection technique used. The recoveries were evaluated at three concentration levels by a matrix-matched calibration and were in the ranges of 83-113 % (relative standard deviations (RSD) ≤ 14 %) and 88-109 % (RSD ≤ 11 %) for UV and PA detection, respectively, highlighting very good performances of the method, even for the more polar analytes. Method detection limits ranged from 4 µg/kg (BTZ) to 493 µg/kg (PNT) and from 4 µg/kg (HPPH) to 11 µg/kg (BTZ) for UV and PA detection, respectively. The method was finally compared with a microwave-assisted extraction procedure which provided less satisfactory extraction performances than the optimized QuEChERS procedure.

QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices: a critical review.

Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up technique originally developed for recovering pesticide residues from fruits and vegetables. Since its introduction, and until December 2013, about 700 papers have been published using the QuEChERS technique, according to a literature overview carried out using SciFinder, Elsevier SciVerse, and Google search engines. Most of these papers were dedicated to pesticide multiresidue analysis in food matrices, and this topic has been thoroughly reviewed over recent years. The QuEChERS approach is now rapidly developing beyond its original field of application to analytes other than pesticides, and matrices other than food, such as biological fluids and non-edible plants, including Chinese medicinal plants. Recently, the QuEChERS concept has spread to environmental applications by analyzing not only pesticides but also other compounds of environmental concern in soil, sediments, and water. To the best of our knowledge, QuEChERS environmental applications have not been reviewed so far; therefore, in this contribution, after a general discussion on the evolution and changes of the original QuEChERS method, a critical survey of the literature regarding environmental applications of conventional and modified QuEChERS methodology is provided. The overall recoveries obtained with QuEChERS and other extraction approaches (e.g., accelerated solvent extraction, ultrasonic solvent extraction, liquid/solid extraction, and soxhlet extraction) were compared, providing evidence for QuEChERS higher recoveries for various classes of compounds, such as biopesticides, chloroalkanes, phenols, and perfluoroalkyl substances. The role of physicochemical properties of soil (i.e., clay and organic carbon content, as well as cation exchange capacity) and target analytes (i.e., log KOW, water solubility, and vapor pressure) were also evaluated in order to interpret recovery and matrix effect data.