Occurrence of persistent and mobile chemicals and other contaminants of emerging concern in Spanish and Portuguese wastewater treatment plants, transnational river basins and coastal water.

This work investigated, during one year, the occurrence and fate of 52 contaminants of emerging concern (CECs) in transnational river basins and coastal areas of the North of Portugal and Galicia (NW Spain) and the wastewater treatment plants (WWTPs) discharging on these environments. The different CECs investigated included pharmaceuticals, personal care products, industrial chemicals, among others, of which ca. 90 % would fulfill the persistence, mobility and toxicity criteria proposed by the German Environmental Agency. The results showed the ubiquitous presence of these CECs and an incomplete removal of over 60 % of them with current conventional WWTPs. These findings highlight the requirement of a prominent and coordinated upgrade of WWTP treatments in order to meet the future European Union regulations on urban wastewater treatment and surface water quality. In fact, even some compounds exhibiting high removals, such as caffeine or xylene sulfonate, were frequently detected in river and estuarine waters at the high ng L-1 level. Thus, our preliminary risk assessment study concluded that 18 of the CECs presented a potential risk for the environment, being caffeine, sulpiride, perfluorooctanoic acid (PFOA), diclofenac, fipronil and perfluorobutanoic acid (PFBA) the most concerning ones. Yet, additional toxicity data as well as a more robust information on persistence and mobility of CECs are necessary for better estimating the magnitude of the problem and improve risk assessment. As an example, in the case of the antidiabetic metformin, recent research has revealed toxicity for model fish species at concentration levels below those found in 40 % of the river water samples analyzed in this work.

Screening of Contaminants of Emerging Concern in Surface Water and Wastewater Effluents, Assisted by the Persistency-Mobility-Toxicity Criteria.

Contaminants of emerging concern (CECs) are compounds of diverse origins that have not been deeply studied in the past which are now accruing growing environmental interest. The NOR-Water project aimed to identify the main CECs and their sources in the water environment of Northern Portugal-Galicia (located in northwest Spain) transnational region. To achieve these goals, a suspect screening analytical methodology based on the use of liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) was applied to 29 sampling sites in two campaigns. These sampling sites included river and sea water, as well as treated wastewater. The screening was driven by a library of over 3500 compounds, which included 604 compounds prioritized from different relevant lists on the basis of the persistency, mobility, and toxicity criteria. Thus, a total of 343 chemicals could be tentatively identified in the analyzed samples. This list of 343 identified chemicals was submitted to the classification workflow used for prioritization and resulted in 153 chemicals tentatively classified as persistent, mobile, and toxic (PMT) and 23 as very persistent and very mobile (vMvP), pinpointing the relevance of these types of chemicals in the aqueous environment. Pharmaceuticals, such as the antidepressant venlafaxine or the antipsychotic sulpiride, and industrial chemicals, especially high production volume chemicals (HPVC) such as ε-caprolactam, were the groups of compounds that were detected at the highest frequencies.

Development and application of an in-house library and workflow for gas chromatography-electron ionization-accurate-mass/high-resolution mass spectrometry screening of environmental samples.

This work presents an optimized gas chromatography-electron ionization-high-resolution mass spectrometry (GC-EI-HRMS) screening method. Different method parameters affecting data processing with the Agilent Unknowns Analysis SureMass deconvolution software were optimized in order to achieve the best compromise between false positives and false negatives. To this end, an accurate-mass library of 26 model compounds was created. Then, five replicates of mussel extracts were spiked with a mixture of these 26 compounds at two concentration levels (10 and 100 ng/g dry weight in mussel, 50 and 500 ng/mL in extract) and injected in the GC-EI-HRMS system. The results of these experiments showed that accurate mass tolerance and pure weight factor (combination of reverse-forward library search) are the most critical factors. The validation of the developed method afforded screening detection limits in the 2.5-5 ng range for passive sampler extracts and 1-2 ng/g for mussel sample extracts, and limits of quantification in the 0.6-3.2 ng and 0.1-1.8 ng/g range, for the same type of samples, respectively, for 17 model analytes. Once the method was optimized, an accurate-mass HRMS library, containing retention indexes, with ca. 355 spectra of derivatized and non-derivatized compounds was generated. This library (freely available at https://doi.org/10.5281/zenodo.5647960 ), together with a modified Agilent Pesticides Library of over 800 compounds, was applied to the screening of passive samplers, both of polydimethylsiloxane and polar chemical integrative samplers (POCIS), and mussel samples collected in Galicia (NW Spain), where a total of 75 chemicals could be identified.

Combination of different chromatographic and sampling modes for high-resolution mass spectrometric screening of organic microcontaminants in water.

This study explores the combination of two sampling strategies (polar organic compounds integrative sampler (POCIS) vs. spot sampling) and four chromatographic retention modes (reversed-phase liquid chromatography (RPLC), hydrophilic interaction liquid chromatography (HILIC), mixed-mode liquid chromatography (MMLC) and supercritical fluid chromatography (SFC)) for high-resolution mass spectrometry (HRMS) screening of organic pollutants in water samples. To this end, a suspect screening approach, using iterative data-dependent tandem mass spectrometry (MS/MS) driven by a library of 3227 chemicals (including pharmaceuticals, pesticides, drugs of abuse, human metabolites, industrial chemicals and other pollutants), was employed. Results show that POCIS can afford a larger number of positive identifications as compared to spot sampling. On the other hand, the best suited retention mechanisms, in terms of identified analytes, are SFC, and followed by RPLC, MMLC and HILIC. However, the best combination (POCIS + SFC) would only allow the identification of 67% of the detected analytes. Thus, the combination of the two sampling strategies, spot and passive sampling, with two orthogonal retention mechanisms, RPLC and SFC, is proposed in order to maximize the number of analytes detected (89%). This strategy was applied to different surface water (river and estuary) samples from Galicia (NW Spain). A total of 155 compounds were detected at a confidence level 2a, from which the major class was pharmaceuticals (61%).

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain).

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8-317 ng/g dry weight (dw)) followed by PCBs (0.47-261 ng/g dw), UV filters (1.4-157 ng/g dw), PFCs (0.53-62 ng/g dw), OCPs (0.07-29 ng/g dw), PBDEs (0.31-6.6 ng/g dw) and NFRs (0.07-3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013.

Organochlorine Pesticides (OCPs) in raft mussels coming from Galician rías.

This survey gives an overview of the range of organochlorine pesticides (OCPs) α and γ-HCH (lindane), HCB, pp´-DDE, pp´-DDD, op´-DDT, pp´-DDT, aldrin, dieldrin, endrin, isodrin and trans-nonachlor in raft mussels cultivated in several polygons of the Galician Rías (Ares-Betanzos, Muros-Noia, Arousa, Pontevedra and Vigo) during the period 1998-2014. A significant number of OCPs were detected, but the levels found were generally low, mainly in the recent samplings (2010-2014). The levels of ∑DDs (sum of DDTs and its metabolites, pp´-DDE and pp´-DDD) ranged between 0.22 ng/g dry weight (dw) in samples from the Ría of Pontevedra and 46.4 ng/g dw in mussels from the Ría of Arousa. Both aldrin and endrin were not detected or were below the analytical limits of detection. With regard to other pesticides, dieldrin is the major compound, followed by γ-HCH, isodrin, α-HCH and transnonachlor. Significant ANOVA regressions indicated variations in levels of some OCPs with the biological parameters (lipid, condition index and shell length). Univariate and multivariate analysis of OCP levels revealed no significant differences between Rías. Temporal trends showed an important decline of OCPs in the studied samples during the period 1998-2014.

Geographical distribution and time trends of polychlorinated biphenyls in raft mussel from Galician coast (1998-2013).

PCBs were analyzed in raft mussels cultured in several polygons from Galician Rías (Rías of Ares-Betanzos, Muros-Noia, Arousa, Pontevedra and Vigo) during the period 1998-2013. The main aim of this work is study the quality of culture marine environment in relation to PCBs compounds. We report the results of a monitoring. The mean levels of ΣPCBs (ten congeners) ranged from 7.41 to 59.50ngg(-1)dw. The isomer concentrations in the Mytilus galloprovincialis cultured in raft were in the order hexachlorobiphenyls>pentachlorobiphenyls>tetrachlorbiphenyls>trichlorobiphenyls. Some biological parameters of mussel were also investigated (shell length, lipid content and condition index) in order to know their influence on ability of PCBs accumulation. ANOVA analysis confirms that levels of most of congeners had a significant relation (p<0.05) with shell length. The geographical patterns and temporal variations of PCBs were also investigated. Principal Component Analysis (PCA) showed differences between geographic areas (Rías) in the distribution of PCBs levels. Samples coming from Rías of Vigo and Ares-Betanzos presented the highest levels of PCBs and samples from Rías of Arousa and Muros-Noia had the lowest levels of these compounds. Time trends (linear regressions) showed a decline of levels of PCB congeners along the period 1998-2013.

Organochlorine pesticide levels in Ensis siliqua (Linnaeus, 1758) from Ría de Vigo, Galicia (N.W. Spain): influence of season, condition index and lipid content.

Levels of organochlorine pesticides (OCPs), including ΣDDTs, γ-HCH, HCB, aldrin, isodrin, trans-nonachlor, heptachlor and dieldrin, were determined in the razor clam, Ensis siliqua, collected monthly from February 2003 to April 2004 from the Islas Cíes in Ría de Vigo (Galicia, Spain). The sum of DDTs ranged from 2.17 to 26.9 ng g(-1) dry weight (dw). Principal component analysis showed seasonal trends in the levels of some OCPs (γ-HCH and dieldrin). Pearson correlations (p < 0.05) were observed between OCP levels and the biometric parameters of condition index and body lipids.

Microwave-assisted solvent extraction and gas chromatography ion trap mass spectrometry procedure for the determination of persistent organochlorine pesticides (POPs) in marine sediment.

Microwave-assisted solvent extraction of persistent organochlorine pesticides (POPs) in marine sediment was developed and optimized by means of two-level factorial designs. Six variables (microwave power, extraction time and temperature, amount of sample, solvent volume, and sample moisture) were considered as factors in the optimization process. The results show that the amount of sample to be extracted and solvent volume are statistically significant for the overall recovery of the studied pesticides, although compromise conditions have to be established with the object of avoiding overpressure in closed vessels. After extraction, a clean up step including the use of a silica cartridge was performed prior to chromatographic determination in order to remove interferences. The optimized procedure was compared to conventional Soxhlet extraction. The MS-MS ion preparation mode was applied to improve the sensitivity and selectivity of the chromatographic technique.

Possible influence of lipid content on levels of organochlorine compounds in mussels from Galicia coast (Northwestern, Spain). Spatial and temporal distribution patterns.

Influence of lipid content of mussel on levels of organochlorine compounds (polychlorinated biphenyls [PCBs] and OC pesticides) has been studied. Mussel samples coming from three sites in Galicia coast (Northwestern, Spain), Moaña and Cangas C from Ría de Vigo and Barallobre from Ría de Ferrol, collected monthly in the period from November 2000 to October 2001, have been analysed. Organochlorine compounds, PCBs (IUPAC nos. 31, 28, 52, 101, 118, 153, 105, 138, 156 and 180) and OC pesticides (pp'-DDE, op'-DDT, pp'-DDT, aldrin, isodrin and endrin) have been extracted by means of Soxhlet and determined by using gas chromatography (electron capture detector [ECD]) and gas chromatography-mass spectrometry. Statistical analysis has been performed using the SPSS statistical package. Few compounds were correlated with lipid content (Pearson product-moment correlation); for samples coming from Barallobre, only the individual PCBs 31, 28, 52 (tri- and tetrachlorinated biphenyls) and 180 (heptachlorinated biphenyl) presented a significant correlation; for Moaña samples, two cyclodiene pesticides, endrin and isodrin, presented a slight significant correlation with lipid content. From these results, it is deduced that the normalization of the concentration of organochlorine compounds to the lipid content is not necessary, in this way, avoiding possible error sources associated to the analytical determination of the lipid contentor reproductive status of mussel. Multivariate techniques (PCA) have been employed in order to study spatial and temporal distribution patterns of organochlorine compounds. The great differences found in studied samples are mainly related to spatial distribution: separations between estuarine bays (samples coming from Ría de Vigo and Ría de Ferrol) and between rural and urban zones (samples coming from Moaña and Cangas C and samples from Barallobre, respectively).

Rapid determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in water samples by using solid-phase microextraction followed by gas chromatography with tandem mass spectrometry.

A rapid and simple method of using solid-phase microextraction was developed for determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in water samples. In this method, the target analyte is extracted from the sample into the polymeric coating of the fused-silica fiber. After exposure, the fiber is thermally desorbed in the heated injection port of the gas chromatograph, and a chromatographic analysis is performed by using low-resolution tandem mass spectrometry. Parameters that may affect the extension of the microextraction process, such as sampling mode, sample volume, temperature, agitation, and sampling time, were studied. Extraction efficiencies for 3 coating fibers were investigated: 100 microm poly(dimethylsiloxane) (PDMS), 65 microm PDMS-divinylbenzene, and 75 microm carboxen-PDMS. Linearity was evaluated (R = 0.999) for a 250-fold concentration range from the fg/mL to the pg/mL level. The 2,3,7,8-TCDD was detected at the fg/mL level when the headspace over the water sample was sampled for 60 min; the limit of detection obtained was better than that of Method 8280B of the U.S. Environmental Protection Agency. The proposed method performed well when applied to the analysis of tap water, lake water, and seawater samples.