Development and validation of a pressurized liquid extraction liquid chromatography–tandem mass spectrometry method for perfluorinated compounds determination in fish

Bioaccumulation and dietary bioaccessibility of microplastics composition and cocontaminants in Mediterranean mussels

Microplastics (MPLs) are contaminants of emerging concern (CECs) ubiquitous in aquatic environments, which can be bioaccumulated along the food chain. In this study, the accumulation of polyethylene (PE), polystyrene (PS) and polyethylene terephthalate (PET) microplastics (MPLs) of sizes below 63 μm was assessed in Mediterranean mussels (Mytilus galloprovincialis spp). Moreover, the potential of mussels to uptake and bioaccumulate other organic contaminants, such as triclosan (TCS) and per- and polyfluoroalkyl substances (PFASs), was evaluated with and without the presence of MPLs. Then, the modulation of MPLs in the human bioaccessibility of co-contaminants was assessed by in vitro assays that simulated the human digestion process. Exposure experiments were carried out in 15 L marine microcosms. The bioaccumulation and bioaccessibility of PE, PS, PET, and co-contaminants were assessed by means of liquid chromatography -size exclusion chromatography-coupled to high-resolution mass spectrometry (LC(SEC)-HRMS). Our outcomes confirm that MPL bioaccumulation in filter-feeding organisms is a function of MPL chemical composition and particle sizes. Finally, despite the lower accumulation and bioaccumulation of PFASs in the presence of MPLs, the bioaccessibility assays revealed that PFASs bioaccessibility was favoured in the presence of MPLs. Since part of the bioaccumulated PFASs are adsorbed onto MPL surfaces by hydrophobic and electrostatic interactions, these interactions easily change with the pH during digestion, and the PFASs bioaccessibility increases.

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

A method of quantification of perfluorinated compounds (PFCs) from atmospheric particulate matter (APM) is described. A single step pretreatment method, selective pressurized liquid extraction (SPLE), was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment steps. An effective sorbent was selected to purify the PFCs during SPLE, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), for quantification of PFCs. Conditions affecting the SPLE efficiency, including temperature, static extraction time, and number of extraction cycles used, were studied. The optimum conditions were found to be 120°C, 10 min, and 3 cycles, respectively. LC-MS/MS method was developed to obtain the optimal sensitivity specific to PFCs. The method detection limits (MDLs) were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/g. To ensure accurate values were obtained, each step of the experiment was evaluated and controlled to prevent contamination. The optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target compounds. Finally, the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to 2019. It is observed that some PFCs follow the trend of total PFC changes, and can be attributed to the environment influencing events and policy enforcement, while others don't seem to change as much with time of the year or from year to year.

Molecular detection of per- and polyfluoroalkyl substances in water using time-of-flight secondary ion mass spectrometry

Detection of per- and polyfluoroalkyl substances (PFASs) is crucial in environmental mitigation and remediation of these persistent pollutants. We demonstrate that time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a viable technique to analyze and identify these substances at parts per trillion (ppt) level in real field samples without complicated sample preparation due to its superior surface sensitivity. Several representative PFAS compounds, such as perfluorooctanesulfonic acid (PFOS), perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluoheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA), and real-world groundwater samples collected from monitoring wells installed around at a municipal wastewater treatment plant located in Southern California were analyzed in this work. ToF-SIMS spectral comparison depicts sensitive identification of pseudo-molecular ions, characteristic of reference PFASs. Additionally, principal component analysis (PCA) shows clear discrimination among real samples and reference compounds. Our results show that characteristic molecular ion and fragments peaks can be used to identify PFASs. Furthermore, SIMS two-dimensional (2D) images directly exhibit the distribution of perfluorocarboxylic acid (PFCA) and PFOS in simulated mixtures and real wastewater samples. Such findings indicate that ToF-SIMS is useable to determine PFAS compounds in complex environmental water samples. In conclusion, ToF-SIMS provides simple sample preparation and high sensitivity in mass spectral imaging, offering an alternative solution for environmental forensic analysis of PFASs in wastewater in the future.

Less is more: a methodological assessment of extraction techniques for per- and polyfluoroalkyl substances (PFAS) analysis in mammalian tissues

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants. Studying the bioaccumulation in mammalian tissues requires a considerable effort for the PFAS extraction from complex biological matrices. The aim of the current work was to select and optimize the most efficient among common extraction strategies for eleven perfluoroalkyl acids (PFAA). Primary extractions from wild boar tissues (liver, kidney, and lung) were performed with methanol at neutral, acidic, or alkaline conditions, or with methyl-tert-butyl ether (MTBE) after ion-pairing with tetrabutylammonium (TBA) ions. A second purification step was chosen after comparing different solid-phase extraction (SPE) cartridges (Oasis WAX, ENVI-Carb, HybridSPE Phospholipid) and various combinations thereof or dispersive SPE with C18 and ENVI-Carb material. The best extraction efficiencies of the liquid PFAA extraction from tissue homogenates were achieved with methanol alone (recoveries from liver 86.6-114.4%). Further purification of the methanolic extracts using dispersive SPE or Oasis WAX columns decreased recoveries of most PFAA, whereas using pairs of two SPE columns connected in series proved to be more efficient albeit laborious. Highest recoveries for ten out of eleven PFAA were achieved using ENVI-Carb columns (80.3-110.6%). In summary, the simplest extraction methods using methanol and ENVI-Carb columns were also the most efficient. The technique was validated and applied in a proof of principle analysis in human tissue samples.

Analytical approaches for screening of per- and poly fluoroalkyl substances in food items: A review of recent advances and improvements

Per and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals characterized by their ubiquitous nature in all environmental compartments which makes them of increasing concern due to their persistence, bioaccumulation, and toxicity (PBT). Several instrumental methodologies and separation techniques have been identified in the literature for the detection and quantification of PFAS in environmental samples. In this review, we have identified and compared common separation techniques adopted for the extraction of PFAS in food items, and analytical methodologies for identification and quantification of PFAS in food items of plant and animal origin, highlighting recent advances in tandem techniques for the high selectivity and separation of PFAS related compounds as well as knowledge gaps and research needs on current analytical methodologies.

Incidence of Potentially Toxic Elements and Perfluoroalkyl Substances Present in Canned Anchovies and Their Impact on Food Safety

Fish plays a key role in a healthy and balanced Italian diet, but it is also subject to the bioaccumulation of different contaminants depending on the geographical or anthropogenic context from which it is derived. In recent years, the European Food Safety Authority (EFSA) has been focusing its attention on consumer toxicological risk, considering emerging contaminants such as perfluoroalkyl substances (PFASs) and potentially toxic elements (PTEs). Regarding fish, anchovies are among the five small pelagic main commercial species in the European Union and the top five fresh species consumed by households in Italy. Considering the lack of data on PFASs and PTEs in this species, our aim was to investigate the mentioned contaminants in salted and canned anchovies collected over 10 months from different fishing areas, even those far apart, to verify possible variations in bioaccumulation and to consider the risk for the consumer. According to our results, the assessed risk was very reassuring also for large consumers. The only concern, related to Ni acute toxicity, also dependent on the different consumers' sensitivity, was related to only one sample.

Per- and Poly-Fluoroalkyl Substances in Portuguese Rivers: Spatial-Temporal Monitoring

Eighteen per-and polyfluoroalkyl substances (PFASs) were investigated in surface waters of four river basins in Portugal (Ave, Leça, Antuã, and Cértima) during the dry and wet seasons. All sampling sites showed contamination in at least one of the seasons. In the dry season, perfluorooctanoate acid (PFOA) and perfluoro-octane sulfonate (PFOS), were the most frequent PFASs, while during the wet season these were PFOA and perfluobutane-sulfonic acid (PFBS). Compounds detected at higher concentrations were PFOS (22.6 ng L-1) and perfluoro-butanoic acid (PFBA) (22.6 ng L-1) in the dry and wet seasons, respectively. Moreover, the prospective environmental risks of PFASs, detected at higher concentrations, were evaluated based on the Risk Quotient (RQ) classification, which comprises acute and chronic toxicity. The results show that the RQ values of eight out of the nine PFASs were below 0.01, indicating low risk to organisms at different trophic levels in the four rivers in both seasons, wet and dry. Nevertheless, in the specific case of perfluoro-tetradecanoic acid (PFTeA), the RQ values calculated exceeded 1 for fish (96 h) and daphnids (48 h), indicating a high risk for these organisms. Furthermore, the RQ values were higher than 0.1, indicating a medium risk for fish, daphnids and green algae (96 h).

EOF and target PFAS analysis in surface waters affected by sewage treatment effluents in Berlin, Germany

Per- and polyfluoroalkyl substances (PFAS) are emerging organic pollutants and can occur in surface and groundwater. To identify the degree of pollution in surface water with PFAS, often targeted HPLC-ESI-MS/MS has been employed in which commonly 30-40 compounds are analyzed. However, other PFAS and organofluorines remain undetected. We sampled surface water of the river Spree and the Teltow Canal in Berlin, Germany, which are affected by the effluent discharge of wastewater treatment plants. Here, we employed high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) for measuring extractable organofluorines (EOF) and compared in a mass balance approach the total fluorine to the identified and quantified PFAS from the targeted analysis. The analysis highlights that the EOF are in the range expected for an urban river system (Winchell et al. in Sci Total Environ 774, 2021). However, downstream of an effluent discharge, the EOF increased by one order of magnitude, e.g., 40.3 to 574 ng F L^-1, along the Teltow Canal. From our target analytes, mostly short-chained perfluorinated carboxylic acids and sulfonates occur in the water, which however makes up less than 10% of the EOF. The increase in EOF in the Teltow Canal correlates well with the increase of perfluorohexanoic acid (PFHxA), indicating that PFHxA is characteristic for the discharged EOF but not responsible for the increase. Hence, it points to PFHxA precursor discharge. The study highlights that EOF screening using HR-CS-GFMAS is necessary to identify the full scale of pollution with regard to PFAS and other organofluorines such as pharmaceutical compounds from the effluent of WWTPs.

An amine-functionalized olefin-linked covalent organic framework used for the solid-phase microextraction of legacy and emerging per- and polyfluoroalkyl substances in fish

Due to the environmental persistence and various health problems associated with per- and polyfluoroalkyl substances (PFASs), they have come under increased public scrutiny. However, the efficient extraction of PFASs from complex media remains challenging. Herein, an olefin-linked covalent organic framework (COF-CN) has been prepared via a Knoevenagel condensation reaction, followed by reduction using LiAlH₄ to form an amine-functionalized COF (COF-NH₂). The characterization results demonstrated that the crystal structure was maintained during the post-modification step. Isothermal and kinetic adsorption studies showed the higher affinity of COF-NH₂ toward PFASs. Based on density functional theory, the adsorption mechanism of the stable six-member-ring structure formed between COF-NH₂ and PFASs via hydrogen bonding was tentatively revealed. After optimizing the solid-phase microextraction parameters, legacy and emerging PFASs were efficiently extracted from fish using the COF-NH₂ coating, followed by detection using ultra-performance liquid chromatography-tandem mass spectrometry. The method exhibited ideal linearity, low limits of quantification, excellent precision, and high relative recoveries. Finally, the bioconcentration kinetics for goldfish was studied, which can provide a feasible platform for investigating the accumulate ion and toxicity of PFASs.

Levels and trends of perfluoroalkyl acids (PFAAs) in water (2013-2020) and fish from selected riverine basins in Spain

The aim of the present study was to assess the presence of perfluoroalkyl acids (PFAAs), namely perfluoroalkane sulfonates and perfluoroalkyl carboxylic acids, in Spanish river basins in order to: identify potential spatiotemporal variations; evaluate the effectiveness of the measures implemented for the reduction/elimination of these pollutants; verify the fulfillment of the Environmental Quality Standards (EQSs) in the European Union. PFOS and PFOA were determined in 116 water samples from four sites in the Duero basin, the largest in the Iberian Peninsula, collected seasonally from 2013 to 2020. In addition, 30 fish sample composites from the sample banks of Duero, Tagus, Ebro, Eastern Cantabrian and Catalonian basins were analyzed for 15 PFAAs. Median PFOS and PFOA concentrations were 0.72 and 0.42 ng/L, ranging from values below the limit of quantification (LOQ) to 81 and 22 ng/L, respectively. During the studied period, 51% of water samples were above the EQS of 0.65 ng/L for PFOS. In the case of fish, the PFOS range was <LOQ-59 with 33% of the samples above the EQS of 9.1 ng/g wet weight. Moreover, fish from the Tagus and Catalonian basins showed median concentrations above the EQS. Particularly, fish collected around highly populated areas such as Madrid and Barcelona showed the greatest PFAA concentrations. Overall, PFAA concentrations in water and fish increased significantly with population density suggesting urban areas as their main source. Although our results suggested decreasing tendencies for PFOS and PFOA in water, significant trends only could be confirmed at two sampling sites.

Development of a magnetic MOF-based M-D-μSPE methodology combined with LC-MS/MS for the determination of fluorotelomer alcohols and its metabolites in animal derived foods

In this study, a novel modified metal organic framework (MOF) was prepared and used as adsorbent of miniaturized solid-phase extraction (M-D-μSPE) for analyzing 8-2 FTOH and its metabolites in edible tissues by LC-MS/MS. This synthesized adsorbent, named as Fe₃O₄@Fe-MIL 101-NH₂ (magnetic Fe-MOF), was characterized. Moreover, the effects factors on the adsorption behavior of the adsorbents for the analytes were investigated and optimized in detail, such as solution pH, adsorbent amount, extraction time, desorption condition. The adsorbtion mechanism of magnetic Fe-MOF might be electrostatic interaction, CF-π hydrophobic and Lewis acid base. Compared with conventional adsorbents (such as PSA, C18), magnetic Fe-MOF reduced matrix effect. The limits of quantification ranged 0.10-1.5 µg/kg. The recoveries of analytes ranged 78.0% - 90.3% in spiked samples, with relative standard deviations less than 12.0%. The developed method was successfully utilized to analyze incurred samples, which proves that it is a rapid, efficient, and sensitive method.

Screening for 32 per- and polyfluoroalkyl substances (PFAS) including GenX in sludges from 43 WWTPs located in the Czech Republic - Evaluation of potential accumulation in vegetables after application of biosolids

Highly persistent, toxic and bioaccumulative per - and polyfluoroalkyl substances (PFAS) represents a serious problem for the environment and their concentrations and fate remain largely unknown. The present study consists of a PFAS screening in sludges originating from 43 wastewater treatment plants (WWTPs) in the Czech Republic. To analyze an extended group of PFAS consisting of 32 PFAS, including GenX and other new replacements of older and restricted PFAS in sludge, a new method was optimized and validated using pressurized solvent extraction, followed by the SPE clean-up step to eliminate the observed matrix effects and LC-MS/MS. The results revealed high PFAS contamination of sewage sludge, reaching values from 5.6 to 963.2 ng g^-1. The results showed that in the majority of the samples (about 60%), PFOS was the most abundant among the targeted PFAS, reaching 932.9 ng g^-1. Approximately 20% of the analyzed samples contained more short-chain PFAS, suggesting the replacement of long-chain PFAS (especially restricted PFOA and PFOS). GenX was detected in 9 samples, confirming the trend in the use of new PFAS. The results revealed that significantly higher contamination was detected in the samples from large WWTPs (population equivalent > 50,000; p-value <0.05). Concerning the application of sludge in agriculture, our prediction using the respective PFAS bioconcentration factors, the observed concentrations, and the legislatively permitted management of biosolids in Czech Republic agriculture revealed that PFAS can cause serious contamination of cereals and vegetables (oat, celery shoots and lettuce leaves), as well as general secondary contamination of the environment.

Preliminary assessment of general population exposure to perfluoroalkyl substances through diet in Greece

Food and drinking water intake are the major routes of exposure to perfluoroalkyl substances (PFASs) for humans. In this study an initial oral exposure assessment of the non-occupationally exposed general Greek population to PFASs is presented. Levels of PFOA and PFOS determined in the present study in 128 food items from the Greek market and previously published analytical results of 43 water samples and 76 egg samples from Greece were combined with food availability data of the DAFNE-ANEMOS database for the calculation of oral intake of PFASs. Fish form the food group with the highest concentration in both PFOA and PFOS. For the general Greek population the estimated average daily intake in PFOA and PFOS when applying the lowerbound mean concentrations in food and drinking water samples is 0.49 and 0.91 ng kg^-1 body weight (b.w.) respectively. The main contributor to oral PFAS intake is fish. A pharmacokinetic model is applied to estimate total intake from blood serum levels reported previously and the predicted values are in agreement with lowerbound estimated values. Weekly intake estimated values are below the tolerable weekly intake recently proposed by EFSA.

Occurrence and bioconcentration of micropollutants in Silver Perch (Bidyanus bidyanus) in a reclaimed water reservoir

This study examined the occurrence of 49 micropollutants in reclaimed water and Silver Perch (Bidyanus bidyanus) living in a reclaimed water reservoir. The numbers of micropollutants detected in reclaimed water, Silver Perch liver, and Silver Perch flesh were 20, 23, and 19, respectively. Concentrations of all micropollutants in reclaimed water, except benzotriazole, were well below the Australian Guideline for Recycled Water (AGRW) values for potable purposes. The concentration of benzotriazole in reclaimed water was 675 ± 130 ng/L while the AGRW value for this compound was 7 ng/L. Not all micropollutants detected in the water phase were identified in the Silver Perch flesh and liver tissues. Likewise, not all micropollutants detected in the Silver Perch flesh and liver were identified in the reclaimed water. In general, micropollutant concentrations in the liver were higher than in the flesh. Perfluorooctane sulfonate (PFOS) was detected at a trace level in reclaimed water well below the AGRW guideline value for potable purposes, but showed a high and medium bioconcentration factor in Silver Perch liver and flesh, respectively. In addition, the risk quotient for PFOS was medium and high when considering its concentration in Silver Perch liver and flesh, respectively. Results reported here highlight the need to evaluate multiple parameters for a comprehensive risk assessment. The results also single out PFOS as a notable contaminant of concern for further investigation.

Pharmaceuticals and endocrine disruptors in raw and cooked seafood from European market: Concentrations and human exposure levels

Pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs) are chemicals of emerging concern that can accumulate in seafood sold in markets. These compounds may represent a risk to consumers through effects on the human reproductive system, metabolic disorders, pathogenesis of breast cancer or development of microbial resistance. Measuring their levels in highly consumed seafood is important to assess the potential risks to human health. Besides, the effect of cooking on contaminant levels is relevant to investigate. Therefore, the objectives of this research were to study the presence and levels of PhACs and EDCs in commercially available seafood in the European Union market, to investigate the effect of cooking on contaminant levels, and to evaluate the dietary exposure of humans to these compounds through seafood consumption. A sampling survey of seafood from 11 European countries was undertaken. Twelve highly consumed seafood types were analysed raw and cooked with 3 analytical methods (65 samples, 195 analysis). PhACs were mostly not detectable or below quantification limits in seafood whereas EDCs were a recurrent group of contaminants quantified in the majority of the samples. Besides, cooking by steaming significantly increased their levels in seafood from 2 to 46-fold increase. Based on occurrence and levels, bisphenol A, methylparaben and triclosan were selected for performing a human exposure assessment and health risk characterisation through seafood consumption. The results indicate that the Spanish population has the highest exposure to the selected EDCs through seafood consumption, although the exposure via seafood remained below the current toxicological reference values.

Validation and determination of nine PFCS in surface water and sediment samples using UPLC-QTOF-MS

In this study, an analytical method for the routine determination of nine perfluorinated compounds (PFCs), using ultra performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (UPLC-QTOF-MS), was developed, validated, and used for their assay in surface water and sediments. The method yielded good linearity with a correlation coefficient (R²) ranging between 0.991 and 0.999 for all the compounds investigated. Limits of detection (LOD) ranged between 0.02 and 0.08 ng/l, while the limit of quantification (LOQ) ranged from 0.065 to 0.261 ng/l. Recovery studies were carried out in replicate assays, and percentage recoveries ranged between 56 and 112% for the nine perfluorinated compounds investigated. The method was applied to determine levels of perflurooctanoic acid (PFOA) and PFOS in surface water and sediment samples collected along the Plankenburg River in Stellenbosch, South Africa. Samples were pre-treated, extracted, and cleaned up via offline solid-phase extraction (SPE) procedures, using hydrophilic-lipophilic balance (HLB) C-18 cartridges. Levels of PFOA and PFOS found in surface water ranged between (12.8 ± 4.24 and 62.62 ± 4.86 ng/l) and (<LOD and 3.8 ng/l), respectively, while levels measured in corresponding sediment samples ranged between 0.14-0.33 ng/g (PFOA) and <LOD and 0.7 ± 0.013 ng/g (PFOS). Concentrations of PFOA and PFOS were suspected to be associated with anthropogenic activities in the vicinity of the sampling areas.

Determination of Trace Perfluoroalkyl Carboxylic Acids in Edible Crop Matrices: Matrix Effect and Method Development

A robust method was developed for simultaneous determination of nine trace perfluoroalkyl carboxylic acids (PFCAs) in various edible crop matrices including cereal (grain), root vegetable (carrot), leafy vegetable (lettuce), and melon vegetable (pumpkin) using ultrasonic extraction followed by solid-phase extraction cleanup and high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The varieties of extractants and cleanup cartridges, the usage of Supelclean graphitized carbon, and the matrix effect and its potential influencing factors were estimated to gain an optimal extraction procedure. The developed method presented high sensitivity and accuracy with the method detection limits and the recoveries at four fortification levels in various matrices ranging from 0.017 to 0.180 ng/g (dry weight) and from 70% to 114%, respectively. The successful application of the developed method to determine PFCAs in various crops sampled from several farms demonstrated its practicability for regular monitoring of PFCAs in real crops.

Perfluoroalkyl substances in the Maltese environment - (I) surface water and rain water

The presence of perfluoroalkyl substances (PFASs) in rain water on the Maltese Islands is reported here for the first time and an extensive survey of these substances in surface water also reported. The Maltese archipelago lies at the centre of the Mediterranean Sea and consists of three main inhabited islands: Malta, Gozo and Comino. Surface water was collected from 41 valleys during the months of February and March 2015 at the peak of the wet season. Rain water was collected during the months of December 2014, February, August, September and October 2015. PFASs were extracted from the water samples using solid phase extraction and the extracts were then analysed using ultra performance liquid chromatography coupled to mass spectrometry in tandem (UPLC-MS/MS). All surface and rain water samples were contaminated with at least one PFAS. PFOS (<LOD - 8.6ng/L) and PFOA (ND - 16ng/L) were the two major PFASs being detected in 100% and 95% of the surface waters respectively. The ΣPFAS concentrations in rain water ranged between 0.38ng/L (1st October 2015) and 6ng/L (21st February 2015). The Maltese archipelago is surrounded by sea and disconnected from any other mainland; therefore the results confirm that remote environments can become contaminated by PFASs from rain events depending on wind prevailing trajectories.

Fast and simple determination of perfluorinated compounds and their potential precursors in different packaging materials

A simple and fast analytical method for the determination of fourteen perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) and ten potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs) in different packaging materials was developed in the present work. In order to achieve this objective the optimization of an ultrasonic probe-assisted extraction (UPAE) method was carried out before the analysis of the target compounds by liquid-chromatography-triple quadrupole-tandem mass spectrometry (LC-QqQ-MS/MS). 7 mL of 1 % acetic acid in methanol and a 2.5-min single extraction cycle were sufficient for the extraction of all the target analytes. The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values after correction with the corresponding labeled standard were in the 69-103 % and 62-98 % range for samples fortified at 25 ng/g and 50 ng/g concentration levels, respectively and MDL values in the 0.6-2.2 ng/g range were obtained. The developed method was applied to the analysis of plastic (milk bottle, muffin cup, pre-cooked food wrapper and cup of coffee) and cardboard materials (microwave popcorn bag, greaseproof paper for French fries, cardboard box for pizza and cinema cardboard box for popcorn). To the best of our knowledge, this is the first method that describes the determination of fourteen PFCs and ten potential precursors in packaging materials. Moreover, 6:2 FTCA, 6:2 FTUCA and 5:3 FTCA analytes were detected for the first time in microwave popcorn bags.

Ultraviolet irradiation-induced substitution of fluorine with hydroxyl radical for mass spectrometric analysis of perfluorooctane sulfonyl fluoride

A rapid and solvent free substitution reaction of a fluorine atom in perfluorooctane sulfonyl fluoride (PFOSF) with a hydroxyl radical is reported. Under irradiation of ultraviolet laser on semiconductor nanoparticles or metal surfaces, hydroxyl radicals can be generated through hole oxidization. Among all fluorine atoms of PFOSF, highly active hydroxyl radicals specifically substitute the fluorine of sulfonyl fluoride functional group. Resultant perfluorooctane sulfonic acid is further ionized through capture of photo-generated electrons that switch the neutral molecules to negatively charged odd electron hypervalent ions. The unpaired electron subsequently initiates α O-H bond cleavage and produces perfluorooctane sulfonate negative ions. Hydroxyl radical substitution and molecular dissociation of PFOSF have been confirmed by masses with high accuracy and resolution. It has been applied to direct mass spectrometric imaging of PFOSF adsorbed on surfaces of plant leaves.

Environmental contaminants of emerging concern in seafood--European database on contaminant levels

Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment to seafood. So-called "contaminants of emerging concern" are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database (www.ecsafeseafooddbase.eu), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data to scientists and regulatory authorities, was developed. The present paper reviews a selection of contaminants of emerging concern in seafood including toxic elements, endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, polycyclic aromatic hydrocarbons and derivatives, microplastics and marine toxins. Current status on the knowledge of human exposure, toxicity and legislation are briefly presented and the outcome from scientific publications reporting on the levels of these compounds in seafood is presented and discussed.

Endocrine disruptor activity of multiple environmental food chain contaminants

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.

Optimization and comparison of several extraction methods for determining perfluoroalkyl substances in abiotic environmental solid matrices using liquid chromatography-mass spectrometry

In this study, four extraction methods of perfluoroalkyl substances (PFASs) in soils and sediments were validated and compared in order to select the one that provides the best recoveries and the highest sensitivity. The determination of PFASs was carried out by liquid chromatography-tandem mass spectrometry. The extraction methods compared were based on (i) an aqueous solution of acetic acid and methanol (recoveries 44-125%, relative standard deviation (RSD) <25%), (ii) methanol (34-109%, <25%), (iii) sodium hydroxide digestion (24-178%, <49%), and (iv) ion pair (35-179%, <31%). The best results were obtained with methanol extraction, which recovered a greater number of PFASs and provided values between 45-103% in sediment and 34-109% in soil with RSDs <25% and limits of quantification (LOQs) between 0.02-0.31 and 0.01-6.00 ng g(-1), respectively. The selected method was successfully applied to Segura River sediments and soil samples taken near the Turia River. This study demonstrates the presence of PFASs in the studied rivers of the Valencian Community (0.07-14.91 ng g(-1) in Segura River sediments; 0.02-64.04 ng g(-1) in Turia River soils). Graphical Abstract Selected matrices and extraction methods for determination of perfluoroalkyl substances.

Enrichment of perfluorinated alkyl substances on polyethersulfone using 1-methylpyperidine as ion-pair reagent for the clean-up of carrot and amended soil extracts

The development of a simple, cheap and environment friendly analytical method for the simultaneous determination of different perfluoroalkyl substances (PFASs) including seven perfluoroalkyl carboxylic acids, three perfluoroalkane sulfonic acids and perfluorooctanesulfonamide in carrot and amended soil was carried out in the present work. The method was based on focused ultrasound solid-liquid extraction followed by extract clean-up through enrichment of the target compounds on a polymeric material using an ion-pair reagent and detection by liquid chromatography-tandem mass spectrometry. The following variables affecting the clean-up step were evaluated: the nature of the polymeric material (polyethersulfone, PES, versus silicone rod), the amount of the polymeric material (from 1 to 9 mg), the ion-pair reagent (1-methylpyperidine, 1-MP, versus tetrabutylammonium salts), the concentration of the ion-pair reagent (from 5 to 50 mM) and the extraction time (from 15 min to 24 h). Optimum clean-up conditions were obtained using preconcentration on 9 mg of PES polymeric material combined with 5 mM 1-MP as ion-pair reagent for 3h. The method was validated in terms of apparent recoveries in the range of 77-140% and 95-137% at the low concentration (50 ng g(-1)) and in the range of 70-136% and 79-132% at the high concentration (290 ng g(-1)) for amended soil and carrot, respectively, after correction with the corresponding labeled standards. Precision, as relative standard deviation, was within 2-23%, while method detection limits were 0.31-2.85 ng g(-1) for amended soil and 0.11-1.83 ng g(-1) for carrot. In the absence of a certified reference material for the target analytes in the matrices studied, inter-method comparison was carried out and the same samples were processed using two independent clean-up procedures, the one developed in the present work and a classical based on solid-phase extraction. Statistically comparable results were obtained according to the one-way analysis of variance for peel, core, leaves as well as amended soil (F(Calc)=2.59, 5.06, 5.82 and 2.34 <F(Crit)=7.71). Finally, the method was applied for the determination of PFASs in uptake experiments where carrots were cultivated in an amended soil polluted with perfluorooctane sulfonic acid (PFOS) at 500 ng g(-1) level. The highest concentration was measured in the carrot leaves (669 ng g(-1)), while the concentrations in peel and core were at the same level (72 ng g(-1) and 62 ng g(-1) respectively), concluding that translocation of PFOS from the soil to the leaves had occurred.

Selecting reliable physicochemical properties of perfluoroalkyl and polyfluoroalkyl substances (PFASs) based on molecular descriptors

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of global environmental pollutants whose environmental fate and adverse effects are of concern. However, data on the basic physicochemical properties of PFASs are scarce. To fill part of the data gaps, improved quantitative structure -property relationship (QSPR) models for prediction of PFAS properties are developed based on the correlation between reported experimental data and molecular descriptors (fluorine number, molar volume and total surface area). Properties include vapor pressure, aqueous solubility, octanol/water partition coefficient, air/water partition coefficient and octanol/air partition coefficient. The fluorine number-descriptor model is based on good statistical results. However, this model cannot distinguish among PFASs with the same number of attached fluorines. Setting aside the fluorine number-descriptor models, models based on molar volume are statistically better than those based on total surface area.Therefore, The PFAS data obtained from the molar volume descriptor model are more reliable than from fluorine number and total surface area descriptor models. These results are intended to improve the understanding of the behavior and fate of PFASs in the environment, at contaminated sites and during remediation.

Fluorous solid-phase extraction (F-SPE) as a pilot tool for quantitative determination of perfluorochemicals in water samples coupled with liquid chromatography-tandem mass spectrometry

As a large group of stable existing organofluorine compounds widely present in the environment, perfluorochemicals (PFCs) could pose potential adverse effects on human health.

Development of an ultraperformance liquid chromatography-tandem mass spectrometry method for the analysis of perfluorinated compounds in fish and Fatty food

This paper reports the development of a method for the quantitative analysis of perfluorinated compounds (PFCs), including C6-C14 perfluorinated carboxylic acids (PFCAs) and C4-C12 perfluorinated sulfonates (PFSAs), in fish and fatty foods by ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) in which the UPLC was equipped a PFC Analysis Kit to eliminate background contamination. Rapid baseline separation was achieved for 17 PFCs within 12 min, and PFCs were well-resolved from potential interferences from taurodeoxycholic acid and branched isomers of PFCs. The method was validated according to Commission Regulation 2002/657/EC of the European Commission with matrices including salmon, beef, egg, and butter. Average spiked recoveries, measured at concentration levels of 0.02 (method limit of quantification (MLOQ)), 0.2, and 2 μg/kg, were in the range of 68-117% with relative standard deviations below 20%. Matrix effects were evaluated and found to be correctable by internal standardization, especially for short- and long-chained PFCs. Trueness was verified against two certified reference materials. The method has also been successfully applied to the analysis of more than 200 food samples of a risk assessment study.

Alternative eluent composition for LC-MS analysis of perfluoroalkyl acids in raw fish samples

A wide range of anthropogenic pollutants that possess serious environmental and health risks are known. One type of these harmful substances that have become a focus of interest during the past decade are perfluoroalkyl acids (PFAAs), which are extensively used in industry for different purposes. Due to the harmful effects that these compounds might cause in living organisms, EFSA and EU CONTAM panel have issued a monitoring program for PFAAs in foodstuffs. This has given rise to intense research dedicated to the analysis of PFAAs over the past few years. This work focuses on chromatographic analysis of three PFAAs in fish. The analytes, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctanesulfonic acid (PFOS), are commonly associated with the production of fluoropolymers. Fluorinated alcohols are used as eluent components, and their possible advantages as eluent modifiers in LC-MS analysis of PFAAs, alternative retention mechanism and enhanced ionization efficiency, are examined. The analyzed fish samples originating from Estonian fresh and marine waters had low contents of PFAAs.

Determination of perfluorinated compounds in aquatic organisms: a review

Bioaccumulation of PFAS in aquatic organisms is an environmental problem of growing concern around the world. This problem has been tackled by regulatory bodies by proposing EQS for biota in EU water bodies and tolerable daily intake for food. The introduction of regulatory limits requires the availability of harmonised and validated analytical methods of sufficient sensitivity. This paper reviews recent advances in analytical methods for analysis of PFAS in aquatic organisms. The methods available for biota analysis are mostly based on three extraction procedures: ion-pair extraction, solvent liquid extraction, and alkaline digestion. The resulting extracts are then subjected to different clean-up or enrichment steps on solid adsorbents, for example graphitized carbon black, C(18), and WAX phases. All methods reviewed in this work give reliable results but are partially validated only, because of the lack of certified reference materials and regular interlaboratory exercises. The few interlaboratory exercises performed on real unspiked samples did not afford satisfactory results for PFAS other than PFOS, especially for matrices with high lipid content, for example mussels. The reasons for those partially negative results have been identified, and can mainly be attributed to calibration procedures and availability and purity of standards. The urgent need for certified reference materials for this type of analysis is emphasized.

Occurrence of perfluorinated compounds in water and sediment of L'Albufera Natural Park (València, Spain)

PURPOSE

Perfluorinated compounds (PFCs) are widely distributed from industrialized to remote locations throughout the world. This study demonstrates the spatial distributions of PFCs in water and sediments from the L'Albufera Natural Park (Valencia, Spain).

METHODS

Grab water and sediment samples were collected. PFCs were extracted from sediments with acidified acetonitrile by ultrasonication and cleaned up by solid-phase extraction (SPE) and from water by SPE. Determination was carried out by liquid chromatography-tandem mass spectrometry.

RESULTS

In 100% of the samples (both water and sediments), perfluorooctane sulfonate (PFOS) and perfluoroctanoic acid (PFOA) were the predominant PFCs. Among the 12 sampling sites, PFOS concentrations in sediments ranged from 0.10 to 4.80 ng/g dry weight and in water from 0.94 to 58.1 ng/L. PFOA concentrations in sediment were from 0.004 to 1.24 ng/g and in water from 0.99 to 120 ng/L. Other perfluorocarboxylic acids (C5, C6, C7, C9, and C10) and perfluorosulfonates (C4 and C10) were also identified in several locations. The sum of all 10 compounds (ΣPFCs) concentration range from 0.99 to 120 ng/L in water and from 0.25 to 17.4 ng/g in sediments. Sediment-water distribution coefficients (log K (D)) were in the range 2.31-4.51 and positively correlated with perfluoroalkyl chain length.

CONCLUSIONS

PFC concentrations in water and sediment were both less than those able to cause acute toxicity; low but detectable PFCs pollution in the L'Albufera Natural Park in Valencia was demonstrated. These compounds are bioaccumulative; thus, the risk associated with these exposures requires a deeper evaluation of long-term chronic toxicity.