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The current study aimed to investigate major knowledge gaps regarding the application of the anodic oxidation (AO) process with boron-doped diamond (BDD) anodes for the remediation of water matrices contaminated with per- and polyfluoroalkyl substances (PFAS). This included: (i) the degradation of ultrashort-chain (C1-C3) and long-chain (C9-C13) PFAS in addition to short- and medium-chain (C4-C8) PFAS, (ii) the application of multi-solute systems with different PFAS content (0.2 µg L−1 versus 2.0 µg L−1) and diversity (24 C1-C13 versus 8 C1-C8) in addition to single-solute systems, (iii) the use of real water matrices in addition to pure water, and (iv) the application of current densities (j) up to 250 mA cm−2 in addition to usual j (≤20 mA cm−2). C1-C4 PFAS with a sulfonated headgroup were the most recalcitrant compounds. By contrast, PFAS ≥ C9 with a sulfonated headgroup and PFAS ≥ C12 with a carboxylic headgroup were potentially instantaneously degraded. The content and diversity of PFAS mainly affected the degradation kinetics of PFEtS (C2), PFPrA (C3), and PFBA (C4). Four real water matrices were under focus: drinking water (DW), urban wastewater after secondary treatment (UWW), and nanofiltration concentrate (NF) and reverse osmosis concentrate (RO) from urban wastewater polishing step. PFAS degradation typically benefited from using real matrices primarily due to the presence of chloride ions and consequent electrogeneration of active chlorine species. However, for waters with a high organic content, namely a chemical oxygen demand (COD) of 319 mg O2 L−1, PFAS degradation was hindered. Furthermore, the removal of most PFAS benefited from the application of j > 20 mA cm−2, and some specific PFAS required the use of j ≥ 250 mA cm−2 to have maximized removal rates.

This thesis investigates the determination of microplastics (MPs), per- and poly luoroalkyl substances (PFAS), and plasticrelated chemicals and their potential effects on environmental and human health. It presents new methods for the determination of MPs in marine sediment, the dynamics of MPs-chemicals association in the marine environment, and further in-vitro bioaccessibility of phthalate compounds and bisphenol A from MPs. Furthermore, this thesis introduces a novel method for PFAS determination in drinking water in response to Directive 2020/2184/EU and it explores a new electrochemical oxidation-based remediation technology.

This review describes a wide variety of analytical approaches for the assessment of human exposure to organic chemicals associated with plastic additives, focusing on works published in the last decade on plasticizers, bisphenols, flame retardants and antioxidants. Physiologically based extraction tests serve as preliminary in-vitro assays to determine the bioaccessibility of these compounds from micro/nanoplastics in body fluids of the gastrointestinal tract, skin, or lung. Whenever plastic-laden compounds become bioavailable, human metabolism is to be monitored through the assessment of phase I and II metabolites. In this regard, analytical methods based on chromatography and mass spectrometry for human biomonitoring of parent compounds and their metabolites in biological samples (mostly urine and plasma) are discussed in depth. This review also covers the role of wastewater-based epidemiology in determining the overall human exposure of a given population to plastic-related species.

An automated procedure for the simultaneous determination of six anionic pesticides, including glyphosate (GLY) and its transformation product aminomethylphosphonic acid (AMPA), was developed and applied to the analysis of environmental water samples. The proposed method combines on-line concentration of water samples (0.160 mL), with compounds separation in an anion-exchange liquid chromatography (LC) column, followed by their selective determination by tandem mass spectrometry (MS/MS). The global procedure was completed in 25 min, providing limits of quantification (LOQs) between 5 ng L−1 and 20 ng L−1, with reduced effect of the surface water matrix in the efficiency of process (SPE and ionization yields). The method was applied to the analysis of grab samples obtained from three watersheds, in two rural and one residential area, in Galicia (Northwest Spain). Out of six investigated compounds, Fosetyl, AMPA and GLY were noticed in the set of processed samples. Their detection frequencies increased from 12% (Fosetyl) to 88% (AMPA). Median concentrations followed the same trend varying from 9 ng L−1 (Fosetyl) to 44 ng L−1 (AMPA). The higher levels and the large seasonal variations in the residues of the latter species were noticed in small rivers affected by discharges of municipal sewage treatment plants (STPs)

Notwithstanding the fact that microplastic fragments were encountered in the human stool, little effort has been geared towards elucidating the impact of chemical additives upon the human health. In this work, standardized bioaccessibility tests under both fasting and fed conditions are herein applied to the investigation of human oral bioaccessibility of plastic additives and monomers (i.e. eight phthalate esters (PAEs) and bisphenol A (BPA)) in low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics. The generation of phthalate monoesters is evaluated in the time course of the bioaccessibility tests. Maximum gastric and gastrointestinal bioaccessibility fractions are obtained for dimethyl phthalate, diethyl phthalate and BPA, within the range of 55–83%, 40–68% and 37–67%, respectively, increasing to 56–92% and 41–70% for dimethyl phthalate and diethyl phthalate, respectively, whenever their hydrolysis products are considered. Bioaccessibility fractions of polar PAEs are dependent upon the physicochemical characteristics of the microplastics, with greater bioaccessibility for the rubbery polymer (LDPE). With the method herein proposed, oral bioaccessible pools of moderately to non-polar PAEs can be also accurately assessed for risk-assessment explorations, with values ranging from 1.8% to 32.2%, with again significantly larger desorption percentages for LDPE. Our results suggested that the highest gastric/gastrointestinal bioaccessibility of the eight PAEs and BPA is reached under fed-state gastrointestinal extraction conditions because of the larger amounts of surface-active biomolecules. Even including the bioaccessibility factor within human risk assessment/exposure studies to microplastics, concentrations of dimethyl phthalate, di-n-butyl phthalate and BPA exceeding 0.3% (w/w) may pose severe risks after oral uptake in contrast to the more hydrophobic congeners for which concentrations above 3% (w/w), except for diethylhexyl phthalate, would

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