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Agricultural management influences the soil ecosystem by affecting its physicochemical properties, residues of pesticides and microbiome. As vineyards grow crops with the highest incidence of pesticides, the aim of this study was to evaluate the impact of conventional and sustainable management systems of vineyards from DOP Ribeiro on the soil’s condition. Samples from soils under three different management systems were collected, and the main soil physicochemical properties were evaluated. A selection of 50 pesticides were investigated by liquid chromatography with tandem mass spectrometry. The bacterial and fungal microbiomes were characterized through amplicon sequencing. The results show that organic agriculture positively influences soil pH and the concentration of some nutrients compared to conventional management. Our microbiome analysis demonstrated that transitioning from conventional to organic management significantly improves several BeCrop® indexes related to key microbial metabolism and soil bio-sustainability. Such a transition does not affect soil alpha diversity, but leads to a higher interconnected microbial network structure. Moreover, differential core genera and species for each management system are observed. In addition, the correlation of the microbiome with geographical distance is evidence of the existence of different microbial terroirs within DOP Ribeiro. Indeed, sustainable management leads to higher nutrient availability and enhances soil health in the short term, while lowering pesticide usage

The consumption of electronic cigarettes is a habit with an increasing prevalence, particularly among youths. Knowing the composition of e-liquids used in these devices represents the first step to understand the potential impact of e-smoking in the health of consumers. Herein, a non-target screening methodology was applied to the identification of volatile and semi-volatile compounds in a set of e-liquids from different suppliers, with different flavors, and containing different kinds of additives, such as nicotine or cannabidiol. To this end, samples were characterized by gas chromatography accurate mass spectrometry, using a time-of-flight mass analyzer. Combination of deconvoluted electronic ionization mass spectra with linear retention index values, obtained for two columns with different selectivity, permitted the identification of more than 250 chemicals with different confidence levels. Among them, respiratory pro-inflammatory compounds, acetals of propylene glycol and glycerin with aldehydes, nicotine-related and non-related alkaloids, and psychoactive cannabinoids were confirmed as concerning compounds in e-liquid samples. Concentration ratios between propylene glycol acetals and parent aldehydes varied in the range from 2% (ethyl vanillin) to more than 80% (case of benzaldehyde). The ratios between the concentrations of delta-9-tetrahydrocannabinol and cannabidiol in e-liquids stayed in the range from 0.02% to 0.3%

Sludge is one of the most problematic residues generated during wastewater treatment. Herein, we validate a single-step, sensitive procedure for the determination of a selection of 46 basic micro-pollutants, either used as pharmaceuticals or pesticides, in sludge from municipal sewage treatment plants (STPs), using liquid chromatography tandem mass spectrometry as determination technique. The proposed method permitted to achieve accurate recoveries (values from 70% to 120%, for samples spiked at different concentration levels) using solvent-based calibration standards. This feature, combined with limits of quantification lower than 5 ng g−1 (dry weight), allowed the rapid and sensitive quantification of target compounds in freeze-dried sludge samples. Out of 46 investigated pollutants, 33 species showed detection frequencies above 85% in a group of 48 sludge samples, obtained from 45 STPs located in the Northwest of Spain. The assessment of eco-toxicological risks associated to sludge disposal as fertilizer in agriculture and/or forestry, considering average concentrations found in sludge samples, highlighted eight pollutants (sertraline, venlafaxine, N-desethyl amiodarone, amiodarone, norsertraline, trazodone, amitriptyline and ketoconazole) representing an environmental hazard based on ratios between predicted soil levels and non-effect concentrations estimated using the equilibrium partition method

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)

Many pharmacologically active compounds are chiral species, and their therapeutic or toxicological effects might differ between isomers. Herein, we develop a fast and sensitive chiral analysis methodology for the determination of eight pharmaceuticals, considered as emerging environmental pollutants and belonging to two different chemical classes, in wastewater and sludge samples. Compounds were separated using supercritical fluid chromatography (SFC) combined with time-of-flight mass spectrometry (TOF-MS) detection. The stationary phase, the modifier and the additive combined with supercritical carbon dioxide (CO2), in the SFC mobile phase, played a major effect in the enantiomeric resolution of selected compounds. Moreover, the composition of the mobile phase affected their ionization efficiency in the electrospray ionization source. Methanol (MeOH), containing a 0.1% of ammonia, was used as CO2 modifier for the separation of compounds in a polysaccharide-type column. Total analysis time was 15.5 min, achieving resolution factors between 1.03 and 2.49 for the eight pairs of enantiomers. In combination with mixed-mode solid-phase extraction and matrix solid-phase dispersion protocols, compounds were determined in wastewater and sludge samples, with limits of quantification in the range of 0.010–0.020 µg L−1 and 3.7–11.1 ng g−1, for aqueous and solid samples, respectively. The amine-type drugs (tramadol, propranolol and venlafaxine) were mostly found in wastewater samples, whilst azolic antimycotics were mainly quantified in sludge. The first group of compounds showed enantiomeric fractions significantly different to those existing in the commercial counterpart pharmaceuticals

Plant protection products used to ensure the product quality and agricultural production can remain on crops as incurred residues, be transferred to different environmental compartments, or even reach elaborated foodstuffs. This Thesis is focused on the optimization and validation of different analytical methodologies for the determination of a relevant number of pesticide residues in vineyard soil and wines, as so as different transformation products. Application of developed methods to wine and soil samples has contributed to advance in the understanding of their processing factors, degradation rates, potential pollution of the soil compartment, and the identification of new transformation products. In this vein, eight publications resulted from the research conducted were divided into four chapters regarding the matrix analyzed, the family of the compounds studied, or the analytical technique employed.

Tramadol (TRA) is a poorly biodegradable pharmaceutical, ubiquitously distributed in the aquatic environment. Herein, we present a thorough comparison of two conventional (UV and chlorination) and two advanced oxidative processes (UV-H2O2 and UV-chlorine), in terms of TRA removal efficiency and transformation products (TPs) formation. The performance of these processes was evaluated in different complexity water samples, previously adjusted at neutral pH. Using 1 mg L−1 as initial concentration of oxidant, UV-chlorine was the most effective process followed by UV-H2O2, direct photolysis and chlorination. The efficiency of the investigated treatments decreased for surface and wastewater samples compared to model solutions. Despite this limitation, the UV-chlorine treatment removed more than 70% of TRA measured in wastewater samples after 5 min of UV irradiation, in presence of 10 mg L−1 of chlorine. UV-chlorine involved additional degradation routes to those described for the rest of treatments, including the formation of tramadol-N-oxide, several chlorinated derivatives, and the volatile species chloroform, 1,1-dichloroacetone and anisole. Some of these specific TPs might pose a similar toxicity to that associated to the parent compound; however, their maximum formation yields remained below 2.5%, decreasing steady for reaction times longer than 5 min

In this work, a procedure for the sensitive and selective determination of chlorhexidine in sludge from municipal sewage treatment plants (STPs) based on matrix solid-phase dispersion (MSPD) and liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) was optimized and validated. Analysis of sewage sludge samples, obtained from different STPs in Northwest Spain from 2018 to 2021, showed that chlorhexidine was ubiquitous in this environmental compartment with concentrations between 0.3 and 16 µg g−1. The toxicity of this pollutant was assessed in in vitro assays considering three different model organisms: Candida albicans, Escherichia coli, and Staphylococcus aureus. C. albicans was the most sensitive of the tested microorganisms to chlorhexidine with a lethal threshold concentration of 0.1 mg L−1. Thus, the lowest observed sludge residue was 3 times higher than the acute toxicity threshold measured for C. albicans. Moreover, E. coli and S. aureus were also affected at chlorhexidine concentrations around 1.8 mg L−1 and 0.5 mg L−1, respectively. So, chlorhexidine residues might affect the population of microorganisms existing in STPs. In addition, the potential phytotoxicity of the compound was evaluated with germination experiments using different model seeds. At the evaluated dose (10 µg g−1 dried soil), chlorhexidine did not affect the germination of Sorghum saccharatum, Lepidium sativum, or Sinapis alba seeds. Thus, amending agriculture soils with chlorhexidine containing sludge is unlikely to affect the germination of plants

Herein, we describe a modular solid-phase extraction (SPE) setup, combining three sorbents, for the effective extraction of neutrals, acidic, and basic micropollutants from wastewater, followed by their further elution in three independent extracts. The performance of this approach was demonstrated for a suite of 64 compounds, corresponding to different chemical families, using liquid chromatography tandem-mass spectrometry (LC–MS/MS). Target compounds were effectively extracted from wastewater samples; moreover, 62 out of 64 species were isolated in just one of the three fractions (neutrals, acids, and bases) obtained from the combination of sorbents. Globally, the efficiency and the selectivity of the SPE methodology improved the features obtained using generic SPE polymers, displaying just reversed-phase interactions. The overall recoveries of the analytical method, calculated against solvent-based calibration standards, stayed between 80 and 120% for 57 and 60 compounds, in raw and treated wastewater, respectively. Procedural limits of quantification (LOQs) varied from 1 to 20 ng L−1. Analysis of urban wastewater samples identified a group of 19 pollutants showing either negligible median removal efficiencies (± 20%) during wastewater treatment, or even a noticeable enhancement (case of the biodegradation product of the drug valsartan), which might be useful as markers of wastewater discharges in the aquatic environment

The performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC–MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5–1.0 ng mL−1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapes

Supercritical fluid chromatography (SFC), combined with mass spectrometry (MS), was employed for the determination of five chiral fungicides, from two different chemical families (acylalanine and triazol) in wine and vineyard soils. The effect of different SFC parameters (stationary phase, chiral selector, mobile phase modifier and additive) in the resolution between enantiomers and in the efficiency of compounds ionization at the electrospray source (ESI) was thorougly described. Under final working conditions, chiral separations of selected fungicides were achieved using two different SFC-MS methods, with an analysis time of 10 min and resolution factors from 1.05 to 2.45 between enantiomers. In combination with solid-phase extraction and pressurized liquid extraction, they permitted the enantiomeric determination of target compounds in wine and vineyard soils with limits of quantification in the low ppb range (between 0.5 and 2.5 ng mL−1, and from 1.3 to 6.5 ng g−1, for wine and soil, respectively), and overall recoveries above 80%, calculated using solvent-based standards. For azolic fungicides (tebuconazole, myclobutanil and penconazole) soil dissipation and transfer from vines to wines were non-enantioselective processes. Data obtained for acylalanine compounds confirmed the application of metalaxyl (MET) to vines as racemate and as the R-enantiomer. The enantiomeric fractions (MET-S/(MET-S+MET-R)) of this fungicide in vineyard soils varied from 0.01 to 0.96; moreover, laboratory degradation experiments showed that the relative dissipation rates of MET enantiomers varied depending on the type of soil

Sludge from sewage treatment plants (STPs) is recognized as a sink of moderate to high lipophilic compounds resistant to biodegradation. Herein, we investigate the presence of emerging pollutants in sewage sludge combining the information provided by mass spectrometry detection, following ultra-performance liquid chromatography (UPLC), with the use of an accurate spectral database of pesticides and pharmaceuticals. In a first step, the performance of matrix solid-phase dispersion, as sample preparation technique, and two non-target data acquisition strategies (data dependent, DDA, and data independent analysis modes, DIA), used in combination with a UPLC quadrupole time-of-flight system, are assessed using a selection of deuterated compounds added either to freeze-dried sludge samples, or to sludge extracts. Possibilities and limitations of both modes are discussed. Following the DDA approach, a group of 68 micropollutants was identified in sludge from different STPs. Some of them are reported in this compartment for the first time. Finally, semi-quantitative concentration data are reported for a group of 37 pollutants in samples obtained from 16 STPs. Out of them, 10 pharmaceuticals, showing detection frequencies and median sludge residues above 50% and 100 ng g−1, respectively; are highlighted as pollutants to be monitored in sludge in order to understand their behaviour during the wastewater treatment

Liquid chromatography tandem mass spectrometry (LC–MS/MS) has been combined with different sample preparation strategies to determine potential pesticide residues existing in wine. Herein, we propose the on-line coupling between solid-phase extraction (SPE), based on a reversed-phase polystyrene-divinyl benzene (PS-DVB) sorbent, and LC–MS/MS for the automated monitoring of a selection of 48 pesticides (37 fungicides and 11 insecticides) in this beverage. Parameters affecting the sensitivity, selectivity, accuracy and robustness of the method are evaluated as function of sample volume, clean-up conditions, and number of extraction-desorption cycles performed with the same SPE cartridge

In this work, the applicability of direct analysis in real time coupled to accurate mass spectrometry (DART-MS) to the quantitative determination of triclosan (TCS) in samples with increasing complexity, from personal care products to extracts from sewage, is investigated. In the first term, DART-MS spectra of TCS as free phenol and as derivatized species are characterized; thereafter, the effects of several instrumental variables in the detectability of TCS (i.e., temperature, solvent, and compound holder) are discussed. Under final selected conditions, TCS was determined from its [M-H]− ions, without need of derivatization, attaining an instrumental limit of quantification of 5 ng mL−1, with a linear response range up to 1000 ng mL−1. Complex matrices, such as solid-phase extracts obtained from environmental water samples, moderately inhibited the ionization efficiency of TCS, with signal attenuation percentages in the range of 6 to 57%, depending on the sample type and on the concentration factor provided by the SPE procedure. The accuracy of results obtained by DART-MS was evaluated using liquid chromatography (LC) with MS detection; in both cases, a time-of-flight (TOF) MS instrument was employed for the selective determination of the [M−H]− ions of TCS (m/z values 286.9439 and 288.9410) using a mass window of 20 ppm. DART-MS did not only provide enough sensitivity to detect the presence of TCS in environmental samples (raw and treated wastewater as well as freeze-dried sludge), but also measured concentrations matched those determined by LC-ESI-TOF-MS, with only slightly higher standard deviations. During analysis of personal care products, containing much higher concentrations of TCS in a less complex matrix, both techniques were equivalent in terms of accuracy and precision

The presence of fungicide and insecticide residues in wine has been largely investigated. However, few studies have addressed the persistence of these compounds in vineyard soils. In this research, we investigate the residues of a relevant number of fungicides and insecticides in vineyard soils, obtained in the Northwest of Spain, at the beginning of each agriculture campaign. Moreover, the dissipation of species showing high concentrations were monitored during the non-vegetative period of vines, in order to understand their soil evolution between application campaigns. To this end, a multiresidue analytical procedure based on pressurized liquid extraction (PLE) followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) determination was first optimized. Under final working conditions, absolute recoveries in the range from 70 to 130% were achieved for 44 out of 51 selected compounds. The method LOQs remained at the low ng g−1 level (0.2–13 ng g−1) with a linear response range up to 500 ng g−1. Analysis of vineyard soils, collected during a 2-year period, from a geographic area with a high incidence of fungal diseases, demonstrated the presence of relevant concentrations of several fungicides and the insecticide imidacloprid (IMI) in this compartment. Most compounds detected at the end of the application season remained in soil at the beginning of the next year campaign. Among them, six fungicides (dimethomorph, boscalid, myclobutanil, penconazole, pyraclostrobin and pyrimethanil) and IMI showed average dissipation efficiencies below 50%, so they pose a potential to accumulate in this kind of soils

The comprehensive identification of organic species existing in indoor environments is a key issue to understand their impact in human health. This study proposes the analysis of condensed water samples, collected with portable dehumidifiers, to characterize semi-volatile compounds in the gas phase of confined areas. Water samples are concentrated by solid-phase extraction (SPE). The obtained extracts are analysed by gas chromatography (GC) time-of-flight mass spectrometry (TOF-MS), following a non-target screening data mining approach. In first term, spectra of deconvoluted compounds are compared with those in NIST low resolution library; thereafter, tentative identifications are verified using an in-house database of accurate electron ionization (EI) MS spectra. Chromatographic (retention index) and spectral data are combined for unambiguous species identification. The potential of condensed water samples to reflect changes in the composition of indoor atmospheres, the match between data obtained using different dehumidifiers, and the relative concentration efficiency of condensed water compared to that attained by active sampling of moderate air volumes are discussed. A total of 141 semi-volatile compounds were identified (98 confirmed against authentic standards) in a set of 21 samples obtained from different homes and working places. This list contains more than 40 fragrances (including several potential allergens), solvents and intermediates in the production of polymeric materials, plasticizers and flame retardants

This PhD dissertation describes several screening strategies for the detection and identification of emerging pollutants in environmental samples. Valuable information about the presence and concentrations of different families of pharmaceuticals, such as antimycotics and cardiovascular, are presented. In addition, the behaviour of the studied pollutants under different tertiary treatments, as well as, the study of the formation of transformation products, are assessed along this thesis. The main point in common in all these studies is the evaluation of the large amount of possibilities offered by the accurate mass spectrometry, derived from the use of TOF instruments, in the identification and inspection of new pollutants.

The suitability of supercritical fluid chromatography, coupled to accurate mass spectrometry (SFC-MS), for the determination of seven commercial neonicotinoid pesticides and one transformation product in wine samples has been investigated. Thorough optimization of the different parameters (column, modifier, back-flush pressure, make up, etc.) affecting the SFC-MS selectivity and sensitivity was carried out. Under final conditions, a 2 mL volume of either red or white wine was extracted by SPE and analysed using external standard calibration achieving limits of quantification from 1 to 11 ng mL−1. Global recoveries ranged between 63 and 118%, depending on the compound and the spiked amount. When compared to UPLC performance, SFC resulted in a better separation of compounds, narrower peaks, comparable sensitivity and significantly lower matrix effects. The developed method allowed the quantification of imidacloprid in around half of the 25 commercial wine samples processed, all of them proceeding from grapes cultivated in year 2018 in the Northwest of Spain, with a maximum concentration of 33 ng mL−1. Acetamiprid was also detected in some white wine samples

The coexistence of the anilinopyrimidine fungicides pyrimethanil (PYR) and cyprodinil (CYP), and suspected metabolites in wine samples was investigated by liquid chromatography (LC) with tandem mass spectrometry (MS/MS), based on triple quadrupole (QqQ) and quadrupole time-of-flight (QTOF) MS instruments. For the first time, quantitative data obtained after solid-phase extraction (SPE) of wine samples have demonstrated the systematic presence of 4-hydroxyanilino derivatives of PYR and CYP in wines containing residues of parent fungicides, at concentrations from 0.2 to 58 ng mL−1. Higher concentration ratios (hydroxylated derivative/active fungicide) were measured in red than in white wines, particularly in case of PYR. On average, the concentrations of PYR-4OH were twice those measured for PYR in red wines. A targeted search of hydroxyl derivatives in wine extracts by LC-QTOF-MS showed the existence of additional hydroxylation positions in the pyrimidine ring and/or in the alkyl substituents bond to this cycle in the structure of both anti-botrytis fungicides. Moreover, free and glycosylated forms of the hydroxylated metabolites for both fungicides coexist in wine samples. In case of CYP, it is proved that hydroxylated and glycosylated metabolites are already present in grapes before vinification

Herein, a method for the simultaneous determination of the currently prescribed sartan drugs (eprosartan, EPR; olmesartan, OLM; losartan, LOS; candesartan, CAN; telmisartan, TEL; irbesartan, IRB; and valsartan, VAL), and the biodegradation product valsartan acid (VALA), in water samples (raw and treated wastewater, river and tap water) was developed. Solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) were employed as concentration and determination techniques, respectively. Different sorbents and elution solvents were tested for sample preparation. Under optimized conditions, samples at neutral pH (6–8 units) were concentrated using mixed-mode (reversed-phase and anionic exchange) cartridges. Thereafter, the sorbent was washed with 5 mL of a methanol: water (1:1) solution, dried under a nitrogen stream and compounds were eluted with 2 mL of methanol: NH3 (98:2). The accuracy of the method (accounting for SPE efficiency and matrix effects during electrospray ionization) was investigated using solvent-based calibration standards. Global recoveries, obtained for different water matrices (tap, river, treated and raw wastewater), ranged from 82% to 134%, with standard deviations between 2 and 18%. LOQs varied from 2 to 50 ng L−1. Analysis of un-spiked samples confirmed: (1) the incomplete removal of sartans at sewage treatment plants (STPs), (2) the formation of VALA during municipal water treatment, and (3) the presence of VALA in the processed tap water samples. Additional findings of the current study are the detection of hydroxylated derivatives of the sartan drugs IRB and LOS in wastewater, and the E-Z isomerization of EPR in environmental water samples

In this work, fabric phase sorptive extraction (FPSE) is investigated for the extraction and preconcentration of ultra-trace level residues of fungicides (19 compounds) and insecticides (3 species) in wine samples. Subsequently, the preconcentrated analytes are selectively determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Parameters affecting the efficiency and repeatability of the extraction are evaluated in depth; moreover, the proposed method is characterized in terms of linear response range, trueness, precision and limits of quantification (LOQs). The set-up of the extraction process and the type of coating were the variables exerting the most prominent effects in the repeatability and the yield of the extraction, respectively. Under optimized conditions, samples (10 mL of wine diluted with the same volume of ultrapure water) were extracted with a small amount of cellulose fabric (3 discs with 4 mm of diameter: total surface 0.38 cm2) coated with a sol-gel polyethylene glycol sorbent (sorbent amount 3.3 mg), immersed in the diluted sample, without being in direct contact with the PTFE covered magnetic stir bar. Following the overnight extraction step, analytes were quantitatively recovered using only 0.3 mL of an ACN-MeOH (80:20) mixture. Under equilibrium sampling conditions, the linear response range of the method varied from 0.2 to 200 ng mL−1, with limits of quantification (LOQs) between 0.03 and 0.3 ng mL−1. Relative recoveries ranged from 77 ± 6% to 118 ± 4%, and from 87 ± 4% to 121 ± 6% for red and white wines, respectively. Application of the optimized method to commercial wines demonstrated the existence of up to 9 out of 22 investigated compounds in the same wine sample. The compound identified at the highest concentration was iprovalicarb (IPR), with a value of 130 ± 9 ng mL−1 in a commercial white wine

En los últimos años, la mala calidad del aire interior ha sido relacionada con diversos tipos de molestias, dolencias y enfermedades, entre las que se encuentran el asma, la bronquitis y diversas alergias, así como el denominado Sick Building Syndrome. En este proyecto se ha llevado a cabo el screening no dirigido de contaminantes orgánicos presentes en muestras reales de polvo pertenecientes a atmósferas interiores. Para el proceso de extracción, detección e identificación de estos compuestos se ha empleado la técnica ASE seguida de GC-QTOF-MS. Además, se ha utilizado una librería de masas de baja resolución (NIST) y una librería de masas exactas creada en el laboratorio, combinadas con el software MassHunter, comercializado por Agilent Technologies., Over the past few years, bad indoor air quality has been related to several sorts of discomfort, minor ailments and illness, including asthma, bronchitis and various allergies, as well as the denominated Sick Building Syndrome. In this project, a non-target screening of indoor pollutants present in real dust samples from interior atmospheres has been carried out. The ASE technique combined with GC-QTOF-MS has been used for the extraction, detection and identification of these compounds. In addition to that, a low resolution mass spectral database (NIST) and an accurate mass spectral database created in the laboratory has been utilised in combination with the software MassHunter, which is commercialised by Agilent Technologies., Nos últimos anos, a mala calidade do aire interior foi relacionada con diversos tipos de molestias, doencias e enfermidades, entre as que se atopan a asma, a bronquite e diversas alerxias, así como o denominado Sick Building Syndrome. Neste proxecto levouse a cabo o screening non dirixido de contaminantes orgánicos presentes en mostras reais de pó pertencentes a atmosferas interiores. Para o proceso de extracción, detección e identificación destes compostos empregouse a técnica ASE seguida de GC-QTOF-MS. Ademáis, utilizouse unha libraría de masas de baixa resolución (NIST) e unha libraría de masas exactas creada no laboratorio, combinadas co software MassHunter, comercializado por Agilent Technologies.

Angiotensin II receptor antagonists (ARA II) are widely employed in the treatment of hypertension-related diseases. Because of their partial metabolization and limited biodegradability, these drugs have become ubiquitous pollutants in the aquatic environment, including surface water. This research evaluated the reactivity of the ARA II drugs: irbesartan (IRB), losartan (LOS) telmisartan (TEL) and valsartan (VAL) with free chlorine. Responses of parent compounds and their transformation products (TPs) were followed by liquid chromatography (LC) with quadrupole (Q) time-of-flight (TOF) mass spectrometry. Degradation experiments were carried out using ultrapure and river water samples, adjusted at different pHs and, in some cases, adding a small amount (ng mL−1 level) of bromide salts. Whilst TEL and VAL remained stable in presence of relatively high concentrations of free chlorine (10 mg L−1), IRB and LOS were removed according to a pseudo-first order kinetics model. Considering an initial chlorine concentration of 10 mg L−1, their half-lives varied between 6 and 734 min, depending mostly on the water pH. IRB reacted with free chlorine through hydroxylation processes, with and without molecular cleavage and re-arrangements in the imidazolone ring. Its TPs showed a lower in-silico predicted toxicity than the parent drug. In case of LOS, two major competitive degradation routes were identified. They involved replacement of the methanol group attached to the imidazole cycle by chlorine or bromine, and the cleavage of this cycle with removal of the chlorinated carbon and the nitrogen in alpha position. The TPs generated following the first route are predicted to be more toxic than LOS

Os pesticidas son compostos empregados en viñas arredor do mundo para garantir unha protección na colleita con poucas perdas, producidas por distintos organismos, en uvas utilizadas para a fabricación do viño. O modo de acción destes compostos baséase na intromisión sobre o metabolismo de diferentes organismos sen afectar á vide. Un acrecentamento no uso destos compostos pode fixar a existencia de residuos nas uvas no momento da colleita onde poden chegar ao viño que se produce coas mesmas. Por ese motivo, estipulouse unha lexislación que regula a cantidade máxima de residuos de pesticidas en uvas, e, aínda que a día de hoxe non hay valores regulamentados no viño, recoméndase que non superen ao 10 % dos límites en uvas. Neste estudo traballouse con diferentes tipos de pesticidas, funxicidas principalmente aínda que tamén algún insecticida, co obxecto de poder detectar a maior cantidade destas sustancias en viños comerciais optimizando a extracción por medio da extracción en fase sólida (SPE) e detección por medio de cromatografía de líquidos acoplada a espectrometría de masas en tándem (LC-MS/MS). Preséntase unha metodoloxía analítica simple, rápida e robusta que pode ser aplicada en laboratorios de control de alimentos, Pesticides are compounds that are used in vineyards around the world to ensure protection at harvest with a few loss, produced by different organisms, in grapes used to make wine. The mode of action of these compounds is based on the interference on the metabolism of different organisms without affecting the vine. An increase in the use of these compounds can determine the existence of residues in grapes at the time of harvest, from where they can reach the wine that is elaborated with the same ones. For this reason, legislation has been established to regulate the maximum amount of pesticide residues in grapes, and although there are currently no regulated values in wine, it is recommended that they do not exceed 10% of the limits on grapes In this study we have worked with different types of pesticides, mainly fungicides but also some insecticide, with the purpose of being able to detect the greatest amount of these substances in commercial wines, extraction has been optimized by solid phase extraction (SPE) and detection has been optimized by liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS/MS). It is presented a simple, fast and robust analytical methodology that can be implemented in food control laboratories., Los pesticidas son compuestos que se emplean en viñedos de todo el mundo para garantizar una protección en la cosecha con escasas pérdidas, producidas por diferentes organismos, en uvas empleadas para la elaboración del vino. El modo de acción de estos compuestos se basa en la interferencia sobre el metabolismo de diferentes organismos sin afectar a la vid. Un incremento en el empleo de estos compuestos puede determinar la existencia de residuos en las uvas en el momento de la cosecha, desde donde pueden alcanzar el vino que se elabora con las mismas. Por ese motivo, se ha establecido una legislación que regule la cantidad máxima de residuos de pesticidas en uvas, y aunque a día de hoy no hay valores regulados en el vino,se recomienda que no excedan al 10% de los límites en uvas. En este estudio se ha trabajado con distintos tipos de fitosanitarios, fungicidas principalmente aunque también algún insecticida, con el objetivo de poder detectar la mayor cantidad de estas sustancias en vinos comercialesoptimizando la extracción mediante extracción en fase sólida (SPE) y detección mediante cromatografía de líquidos acoplada a espectrometría de masas en tándem (LC-ESI-MS/MS). Se presenta una metodología analítica sencilla, rápida y robusta que puede ser implementada en laboratorios de control de alimentos

Esta Tesis describe el desarrollo de metodología analítica para la determinación de compuestos de origen natural (estilbenos y Ocratoxina A) y sintéticos (fungicidas e insecticidas) en vinos comerciales. Los métodos propuestos se centran en el uso de espectrometría de masas, empleando diferentes fuentes de ionización y analizadores de masas, en combinación con técnicas cromatográficas. En la memoria se incluyen datos cuantitativos para un número relevante de muestras de vino. Además, se recogen diferentes estudios de transformación, llevados a cabo en el laboratorio simulando condiciones ambientales, en los que se investiga la estabilidad y se identifican los posibles productos de transformación de diferentes pesticidas empleados en viticultura a través del uso de espectrometría de masas exactas. También se incluye una evaluación detallada de las rutas de transformación fotoquímicas del resveratrol y compuestos análogos con interés comercial.

En esta Tesis Doctoral se describe el desarrollo y la aplicación de nuevas estrategias de análisis útiles para la determinación de contaminantes emergentes azólicos en muestras medioambientales. Concretamente, las familias estudiadas son los benzotriazoles inhibidores de procesos de corrosión, los estabilizadores UV benzotriazólicos (Tinuvin), y los fármacos antimicóticos. Los métodos de análisis desarrollados consisten en una primera etapa de preparación de muestra mediante SPE, SPME o DLLME, para muestras líquidas, y MSPD, para muestras sólidas; seguida de una segunda etapa de determinación de las sustancias mediante LC-MS/MS o GC-MS/MS con analizador de masas híbrido cuadrupolo-tiempo de vuelo (QTOF) de última generación. Los métodos analíticos aquí desarrollados han sido utilizados para llevar a cabo estudios medioambientales en los que se han analizado muestras de agua tomadas en ríos de España que soportan vertidos de estaciones depuradoras de aguas residuales, así como en la entrada y la salida de estas plantas, con el objetivo de estimar los coeficientes de eliminación alcanzados en los procesos de tratamiento de aguas residuales. Paralelamente, estas sustancias han sido determinadas en muestras de lodos generados durante estos tratamientos para confirmar o descartar la ocurrencia de procesos de adhesión y sedimentación de estos contaminantes emergentes en la materia particulada. Finalmente, se han llevado a cabo estudios de estabilidad de algunos de los contaminantes emergentes estudiados bajo los efectos de la luz UV. La aplicación de este tipo de radiación como tratamiento terciario en algunas estaciones depuradoras de aguas residuales hace interesante conocer si su eficacia es tal, que consigue mineralizar completamente los compuestos presentes en el agua, o si da lugar a nuevas sustancias que pudieran ser más peligrosas que los compuestos de partida. Además, dado que una fracción de la luz del Sol es radiación UV, es interesante estudiar las reacciones

For the first time, a procedure for the simultaneous determination of the iodinated drug amiodarone and its major metabolite, N-desethylamiodarone, in sludge from urban sewage treatment plants (STPs) is proposed. Matrix solid-phase dispersion (MSPD) followed by on-line cationic exchange clean-up, in mod- ular configuration, was used as sample preparation technique. Liquid chromatography with tandem mass spectrometry (LC–MS/MS), based on a hybrid quadrupole time-of-flight (QTOF) system, was employed for the selective determination of target compounds. The optimized procedure provided exhaustive recov- eries with little effect of the sample matrix in the efficiency of electrospray ionization (ESI). The overall recoveries of the method ranged between 95 and 111%, for samples spiked at different concentration levels. The achieved limits of quantification (LOQs) remained below 10 ng g−1 for both compounds, and the linear response range extended up to 2500 ng g−1. Amiodarone and N-desethylamiodarone were ubiquitous in sludge samples, from different STPs located in the Northwest of Spain, with maximum concentrations above 300 ng g−1 referred to the freeze-dried matrix. They were also present in stabilized sludge (mixed with lime and thermally dehydrated), which is mostly disposed in agriculture fields as fertilizer. Furthermore, mono-iodinated analogues of amiodarone and N-desethylamiodarone were also tentatively identified in some samples from their accurate MS and MS/MS spectra

Solid-phase microextraction (SPME) is an effective technique for the extraction of polybrominated diphenyl ethers (PBDEs) from environmental water samples. Although it has been also applied to sediments, the organic content of this matrix causes an exponential decrease in the yield of the extraction. This work presents an improved SPME procedure for the sensitive determination of six PBDEs (tetra- to hexa-brominated congeners) in sediments containing up to 6% of total organic carbon (TOC). Samples (0.25–0.5g) were accurately weighed in 22mL glass vessels, mixed with a given amount of potassium permanganate, 0.5mL of sulphuric acid and 5mL of water. Extractions were performed at 100°C, for 40min, using a polyacrylate (PA) coated fibre in the headspace (HS) mode. Potassium permanganate showed a dramatic, positive effect on the yield of the extraction. Its optimum amount was related to the TOC of the sediment, with overall highest responses attained for 40mg of oxidant per mg of organic carbon in the SPME vessel. Under final working conditions, the combination of SPME with gas chromatography coupled to tandem mass spectrometry (GC–MS/MS) provided relative standard deviations (RSDs) below 14%, relative recoveries from 76 to 111% and limits of quantification (LOQs) lower than 0.15ngg−1 for all the investigated PBDEs in spiked river and marine sediments with different TOC. The performance of the method was also evaluated satisfactorily with a medium complexity (TOC 6.7%), real-life polluted sediment, previously analyzed in inter-laboratory comparison exercises.

The applicability of disposable polypropylene microporous membranes (MMs) for the concentration of five halogenated anisoles in water samples was investigated. Two microextraction approaches, named MM solid-phase extraction (MMSPE) and liquid-liquid extraction (MMLLE), are proposed. They are based on adsorption of target species onto the surface of the dry membrane and absorption into a few microlitres of solvent embedded in the pores of the membrane, respectively. The effect of several factors, such as sampling mode, type of acceptor solvent, ionic strength of the sample, stirring, sampling time, etc., on the performance of both approaches was thoroughly assessed. After extraction, analytes were recovered from the sorbent using just 0.25 mL of n-hexane and determined by gas chromatography with micro-electron-capture detection (GC-micro-ECD). Under optimised conditions, similar precisions (RSDs from 7 to 14%, under reproducibility conditions) and limits of quantification (values between 0.3 and 15 ng L-1), as well as remarkable linear responses were attained for both techniques; however, MMSPE, operating in the headspace sampling mode (HS), showed faster kinetics for all species, was less affected by the type of matrix and the set-up of the extraction step was simpler, since immobilisation of the extraction solvent in the membrane was not necessary. Obtained results demonstrated, for the first time, the suitability of polypropylene MMs as adsorbents of lipophilic compounds.

A fast and novel sample preparation procedure for the determination of triclosan (TCS) and methyltriclosan (MTCS) in water samples is presented. Dispersive liquid-liquid microextraction, using a ternary mixture consisting of a disperser, an extractant and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) as derivatization reagent, was used for the simultaneous derivatization, case of TCS, and concentration of both species in different water samples. Analytes were determined by gas chromatography with tandem mass spectrometry (GC-MS/MS). Influence of different factors on the performance of the sample preparation process is thoroughly discussed. Under final working conditions, a mixture of 1 mL of methanol, 40 L of 1,1,1-trichloroethane and the same volume of MTBSTFA was added to 10 mL of water in a conical bottom glass tube. After centrifugation, the settled phase was injected directly in the chromatographic system. TCS was quantitatively extracted and converted into the corresponding tert-butyldimethylsilyl derivative, whereas for MTCS an extraction yield around 90% was attained. Limits of quantification between 2 and 5 ng L-1 and reproducibility values below 10% were achieved; moreover, the performance of the extraction process was scarcely affected by the type of water sample. Globally, these values are comparable, or even better, to those reported for other approaches applied to the determination of same compounds, with the advantage of a shorter sample preparation step. Analysis of surface and wastewater samples confirmed the ubiquitous presence of TCS in the aquatic environment at levels from 20 to 700 ng L-1.

An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 hours and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 L. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L-1, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated.

The suitability of an inexpensive polydimethylsiloxane (PDMS) sorbent, produced at industrial scale, for the extraction of polybrominated diphenyl ethers (PBDEs), from tetra- to hexabrominated congeners, from water samples was assessed. Experiments were carried out using samples spiked with a pentabromo diphenyl ether (pentaBDE) mixture, PDMS rods with a diameter of 2 mm and gas chromatography with micro-electron-capture detection (GC-micro-ECD). Influence of several variables on the efficiency of the enrichment step and the further desorption of the analytes was investigated in detail. The best performance was achieved in the headspace sorptive extraction (HSSE) mode, at 95 ºC, using 80 mL water samples containing a 30% of sodium chloride. Extractions were performed overnight using disposable PDMS rods with a length of 10 mm (31 L volume). Analytes were further recovered from the PDMS sorbent using just 1 mL of diethyl ether. This solvent was evaporated and extracts reconstituted with 25 L of isooctane. Under final working conditions absolute extraction efficiencies from 69 to 93% and enrichment factors higher than 2200 folds were achieved for all species. The proposed method provided acceptable precisions (relative standard deviations values under 12%), correlation coefficients higher than 0.998 and the yield of the HSSE process remained constant for different water samples.