Optimization of the ultrasound-assisted extraction method for determining high production volume chemicals in fish liver and skin samples.

The aquatic ecosystem is one of the most delicate environments, housing a diverse range of organisms, including fish, all of which are exposed to a wide variety of pollutants. The accumulation of these harmful substances in fish, which are part of the human diet, presents a significant health risk to humans. In our study, we have optimized an extraction technique to determine the presence of 25 high production volume chemicals in liver and skin samples taken from commonly consumed fish species. We have employed ultrasound-assisted extraction in conjunction with gas chromatography tandem mass spectrometry to achieve this goal. Apparent recoveries of the method ranged from 50% to 111% for both sample types with some exceptions such as most of the benzosulfonamides and benzothiazole. Additionally, the method's detection and quantification limits varied from 0.1 to 1.7 ng g-1 (dry weight, d.w) and 0.2-4.5 ng g-1 (d.w), respectively. Our investigation focused on three frequently consumed fish species in Tarragona: sea bass, sea bream, and turbot. Almost all of the samples we analysed contained traces of contaminants, with phthalates being the most commonly detected. The highest concentrations were observed for diethyl phthalate, with levels peaking at 8350 ng g-1 (d.w.). Organophosphate esters, such as triethyl phosphate and tributyl phosphate, also showed notable presence, with peak concentrations of 93.6 and 34.0 ng g-1 (d.w.), respectively.

Occurrence of high production volume chemicals and polycyclic aromatic hydrocarbons in urban sites close to industrial areas. Human exposure and risk assessment.

Evaluating the occurrence of high production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) in the air is important because they carry a carcinogenic risk and can lead to respiratory or endocrine problems. Examples of HPVCs are organophosphate esters, benzosulfonamides, benzothiazoles, phthalate esters (PAEs), phenolic antioxidants and ultraviolet stabilizers. In this paper we develop a multi-residue method for determining HPVCs and PAHs in air samples via pressurized liquid extraction followed by gas chromatography-mass spectrometry. Air samples were collected by active sampling with high volume samplers using quartz fiber filter for the particulate matter (PM10) and polyurethane foams for gas phase. The compounds found at the highest concentrations were PAEs, with a concentration of up to 24 ng m-3 of DEHP in gas phase and up to 109 ng m-3 of DEHA in PM10. Non-carcinogenic risk assessment results ranged from 9.7E-05 to 9.5E-03 for most of the compounds studied. On the other hand, the results for carcinogenic risk showed that PAHs made the highest contribution.

Selective determination of 2-aminobenzothiazole in environmental water and organic extracts from fish and dust samples.

In the present study, a homemade mixed-mode ion-exchange sorbent based on silica with embedded graphene microparticles is applied for the selective extraction of 2-aminobenzothiazole (NH2BT) followed by determination through liquid chromatography coupled to high-resolution mass spectrometry. The sorbent was evaluated for the solid-phase extraction of NH2BT from environmental water samples (river, effluent wastewater, and influent wastewater), and NH2BT was strongly retained through the selective cation-exchange interactions. Therefore, the inclusion of a clean-up step of 7 mL of methanol provided good selectivity for the extraction of NH2BT. The apparent recoveries obtained for environmental water samples ranged from 62 to 69% and the matrix effect from -1 to -14%. The sorbent was also evaluated in the clean-up step of the organic extract for the extraction of NH2BT from organic extracts of indoor dust samples (10 mL of ethyl acetate from pressurized liquid extraction) and fish (10 mL of acetonitrile from QuEChERS extraction). The organic extracts were acidified (adding a 0.1% of formic acid) to promote the cation-exchange interactions between the sorbent and the analyte. The apparent recoveries for fish samples ranged from 22 to 36% depending on the species. In the case of indoor dust samples, the recovery was 41%. It should be highlighted the low matrix effect encountered in such complex samples, with values ranging from -7 to 5% for fish and dust samples. Finally, various samples were analyzed. The concentration in river samples ranged from 31 to 136 ng/L; in effluent wastewater samples, from 55 to 191 ng/L; in influent wastewater samples, from 131 to 549 ng/L; in fish samples, from 14 to 57 ng/g dried weight; and in indoor dust samples, from

Evaluation of ceramic passive samplers using a mixed-mode strong cation-exchange sorbent to monitor polar contaminants in river water.

Although most of the analytical methods developed for the monitoring of contaminants in environmental waters are based on discrete grab sampling, an alternative of increasing interest is the use of passive sampling. Methods based on passive sampling provide the sampling and pre-concentration of the analytes in-situ, which makes the sample treatment less time consuming and costly than using discrete grab sampling. In this study, ceramic passive samplers (CPSs) using mixed-mode strong cation-exchange sorbent (Oasis MCX) as retention phase were evaluated for the determination of a group of 21 therapeutic and illicit drugs and some of their metabolites in river water samples that were determined by liquid chromatography-tandem mass spectrometry. After assessing the stability of the analytes, the CPSs were calibrated for 9 days with bottled water and river water, obtaining, for the 19 stable compounds, sample rates (Rs) ranging between 0.180 and 1.767 mL/day and diffusion coefficients (De) between 2.02E-8 and 2.81E-7 cm2/s. Once calibrated, CPSs were deployed for the determination of contaminants in the Ebre River, with good reproducibility, and some of the analytes were determined, including amongst others, gabapentin at 76 ng/L, caffeine at 203 ng/L or diclofenac amine at 57 ng/L. The passive sampling method herein presented is simple and feasible and allows the time-integrated analysis of pharmaceuticals and drugs at trace levels in river water. This study opens the possibility of using other mixed-mode sorbents or other types of sorbents as retaining phase on CPSs for the determination of very polar contaminants in water.

Ceramic passive samplers for determining pharmaceuticals and drugs of abuse in river and drinking water.

An important challenge today is to efficiently monitor the presence of polar pharmaceuticals and drugs in surface and drinking waters to ensure its safeness. Most studies rely on grab sampling techniques, which enable the determination of contaminants at a given point and given time. In this study, we propose the use of ceramic passive samplers (CPSs) to increase the representativeness and efficiency of organic contaminant monitoring in waters. Firstly, we have assayed the stability of 32 pharmaceuticals and drugs and found that five of those compounds were unstable. Moreover, we evaluated the retention capabilities of three sorbents (Sepra ZT, Sepra SBD-L, and PoraPak Rxn RP) in solid-phase extraction (SPE) mode and found no differences in terms of recoveries for all three sorbents. We then calibrated CPSs using the three sorbents for the 27 stable compounds over 13 days, with a suitable uptake for 22 compounds with sampling rates between 0.4 and 17.6 mL/day, which indicates high uptake efficiency. CPSs with the Sepra ZT sorbent were deployed in river water (n = 5) and drinking water (n = 5) for 13 days. Some of the studied compounds occurred with a time-weighted concentration, for instance, of 43 ng/L for caffeine, 223 ng/L for tramadol or 175 ng/L for cotinine in river water.

Extraction of selected benzothiazoles, benzotriazoles and benzenesulfonamides from environmental water samples using a home-made sol-gel silica-based mixed-mode zwitterionic sorbent modified with graphene.

A novel sol-gel silica-based mixed-mode zwitterionic sorbent modified with graphene microparticles was synthesized. Thanks to the inclusion of multiple functional groups and graphene microparticles to exert a wide range of intermolecular/interionic interactions including dipole-dipole interactions, ion-exchange interactions and π-π interactions, the sorbent showed high retention in the solid-phase extraction (SPE) of benzothiazoles, benzotriazoles and benzenesulfonamides. The SPE protocol was optimized in terms of pH, sample loading volume and elution conditions using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method based on SPE followed by LC-HRMS was validated. Apparent recoveries at two levels of concentration were in the range from 48 to 85% (in most cases) in matrices such as influent wastewater, matrix effect was lower than ±30% in most cases, method detection and quantification limits being lower than 20 ng/L and repeatability and reproducibility between days were lower than 18% (n = 4). River, effluent and influent wastewaters samples were analyzed, obtaining concentrations ranging from 3 to 175 ng/L in river samples, from 12 to 499 ng/L in effluent samples and from 15 to 632 ng/L in influent samples, when the compounds were above the method quantification limits.

Determination of Organophosphate Ester Metabolites in Seafood Species by QuEChERS-SPE Followed by LC-HRMS.

Organophosphate triesters are compounds widely used in industries and are ubiquitous in the environment, where they can be transformed into organophosphate diesters. Some organophosphate diesters are also used by industry. Several studies suggest organophosphate diesters can have toxic effects for reproduction, and hazardous and mutagenic properties. Due to the impact these compounds can have on marine biota and human beings through the consumption of fish and shellfish, it is necessary to study their presence in widely consumed seafood species. We therefore developed an analytical method for determining six of the most common organophosphate diesters in seafood. The procedure is based on the Quick, Easy, Cheap, Effective, Rugged and Safe extraction method and a solid phase extraction clean-up, followed by liquid chromatography coupled to high-resolution mass spectrometry. The method was optimised and validated for seafood with different lipid content, providing satisfactory relative recoveries (from 89 to 138%) and limits of detection (1.0-50 ng g-1 dry weight), as well as repeatability values (RSD% (n = 5, 100 ng g-1 (dry weight)) lower than 15%. Eight seafood species were analysed using this method and two organophosphate diesters were detected and quantified in all the samples, demonstrating the suitability of the method.

Occurrence of organic contaminants bonded to the particulate matter from outdoor air influenced by industrial activities.

This paper discusses the occurrence of organic contaminants bonded to particulate matter (PM) in ambient air. We describe the presence and concentration levels of contaminants mainly reported in atmospheres close to factories or at locations influenced by them, and the relationship between factory emissions and the type of organic contaminants found in PM samples from the surrounding air. Many organic contaminants have been found in these types of samples, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Their sources, fates and distributions in the ambient atmosphere are therefore well known. However, in addition to these most studied compounds, others are also of concern nowadays due to their detection and toxic effects on the environment. The continuous updating of regulations on these contaminants and the appearance of new air pollutants make it important to be aware of their occurrence. This will help to either establish new guidelines for the newer contaminants or reassess existing limitations for known ones. Moreover, if we know their occurrence, we can analyse their sources, destinations and distributions in the outdoor air.

Development of sol-gel silica-based mixed-mode zwitterionic sorbents for determining drugs in environmental water samples.

Four novel mixed-mode zwitterionic silica-based functionalized with strong moieties sorbents were synthesized and evaluated through solid-phase extraction (SPE) to determine acidic and basic drugs in environmental water samples. All sorbents had the same functionalization: quaternary amine and sulfonic groups and C18 chains so that hydrophobic and strong cationic exchange (SCX) and strong anionic exchange (SAX) interactions could be exploited, in addition, two of them had carbon microparticles embedded. All sorbents retained both acidic and basic compounds in the preliminary assays but only the basic compounds were retained selectively through ionic exchange interactions when a clean-up step was introduced. The SPE method was therefore optimized to promote the selective retention of the basic compounds, initially with the two best-performing sorbents. After optimization of the SPE protocol, these sorbents were evaluated for the analysis of environmental water samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method with the best-performing sorbent was then validated with 100 mL of river samples and 50 mL of effluent wastewater samples in terms of apparent recoveries (%Rapp) spiking samples at 50 ng/L (river) and 200 ng/L (river and effluent), matrix effect, linear range, method quantification and detection limits, repeatability, and reproducibility. It should be highlighted that %Rapp ranged from 40 to 85% and matrix effects ranged from -17 to -4% for spiked river samples. When the method was applied to river and effluent wastewater samples, most compounds were found in the range from 24 to 1233 ng/L with detection limits from 1 to 5 ng/L.

Evaluation of air quality in indoor and outdoor environments: Impact of anti-COVID-19 measures.

This study monitors the presence of 88 volatile organic compounds (VOCs) and semi-volatile organic compounds (semi-VOCs) at the gas phase of seven indoor settings in a school in the city of Tarragona, Spain, and five outdoor locations around the city. The VOCs and semi-VOCs monitored were solvents (∑Solvents), aldehydes (∑Aldehydes), emerging organic compounds (∑EOCs), and other VOCs and semi-VOCs (∑Others). Passive sampling campaigns were performed using Carbopack X tubes followed by thermal desorption coupled to gas chromatography with mass spectrometry (TD-GC-MS). Overall, 70 of the target compounds included in the method were determined in the indoor air samples analysed, and 42 VOCs and semi-VOCs in the outdoor air samples. Our results showed that solvents were ubiquitous throughout the school at concentrations ranging from 272 µg m-3 to 423 µg m-3 and representing 68%-83% of total target compounds (∑Total). The values of ∑Total in 2021 were three times as high as those observed at the same indoor settings in 2019, with solvents experiencing the greatest increase. A plausible explanation for these observations is the implementation of anti-COVID-19 measures in the indoor settings, such as the intensification of cleaning activities and the use of hydroalcoholic gels as personal hygiene. The ∑Total values observed in the indoor settings evaluated were twenty times higher than those found outdoors. ∑Solvents were the most representative compounds found indoors (74% of the ∑Total). The concentrations of VOCs and semi-VOCs observed in the outdoors were strictly related to combustion processes from automobile traffic and industrial activities, with ∑Others contributing 58%, ∑Solvents 31%, and ∑Aldehydes 11% of the ∑Total. EOCs, on the other hand, were not detected in any outdoor sample.

Multiresidue analytical method for high production volume chemicals in dust samples, occurrence and human exposure assessment.

A multiresidue analytical method based on pressurised liquid extraction and gas-chromatography mass spectrometry was developed to determine 22 compounds belonging to different chemical families in indoor dust.: Seven organophosphate esters, six phthalate esters, three benzotriazoles, five benzothiazoles and four benzenesulfonamides were included in the present study, all of them belonging to the category of high production volume chemicals (HPVCs). Apparent recoveries ranged between 45% and 123% and method quantification limits ranged from 0.03 µg/g to 3.8 µg/g. The occurrence of the selected HPVCs was evaluated in indoor dust from different locations in the Tarragona (Catalonia, Spain) region. Two benzenesulfonamides, ortho-toluenesulfonamide and para-toluenesulfonamide, were detected in dust samples for the first time. Phthalate esters and organophosphate esters were the most abundant compounds found, and di-(2-ethylhexyl) phthalate (DEHP) was determined at the highest concentrations. With the data obtained, human exposure was assessed by calculating the estimated daily intakes (EDI) via ingestion and dermal contact. Non-carcinogenic and carcinogenic risk assessments found no risks in any of the scenarios tested, which included two age classes (children and adults) and two possible exposure scenarios (median and worst-case scenario), except for the evaluation of carcinogen risk due to ingestion of DEHP in the worst-case scenario.

Hypercrosslinked polymer microspheres decorated with anion- and cation-exchange groups for the simultaneous solid-phase extraction of acidic and basic analytes from environmental waters.

Mixed-mode ion-exchange sorbents were introduced to improve the selectivity and retention of solid-phase extraction (SPE) sorbents. Mixed-mode ion-exchange sorbents integrate reversed-phase chemistry with ion-exchange groups to promote favourable interactions with ionic species. Nevertheless, a need to extract analytes with acidic and basic properties simultaneously within the same SPE cartridge led to the introduction of novel amphoteric/zwitterionic sorbents, which incorporate cation- and anion-exchange moieties within the same functional group attached to the polymeric network. In the present study, the development, preparation and SPE evaluation of two novel hypercrosslinked zwitterionic polymeric sorbents, functionalised with either strong anion-exchange (SAX) and weak cation-exchange (WCX) or weak anion-exchange (WAX) and strong cation-exchange (SCX) groups (namely HXLPP-SAX/WCX and the HXLPP-WAX/SCX), is presented for the simultaneous retention of acidic and basic compounds. The sorbents were prepared by a precipitation polymerisation route which yielded poly(divinylbenzene-co-vinylbenzylchloride) as a precursor polymer; subsequently, the precursor polymer was hypercrosslinked, to increase the specific surface areas and capacities of the sorbents, and then functionalised to impart the zwitterionic character. The HXLPP-SAX/WCX sorbent was decorated with quaternised sarcosine groups and the HXLPP-WAX/SCX sorbent was decorated with taurine moieties. The SPE parameters were optimised to exploit the ionic interactions between compounds and the functional groups. The optimal conditions involve a washing step to remove the compounds retained by hydrophobic interactions, thus increasing the selectivity. The optimised SPE protocol used the quaternised sarcosine-based sorbent followed by liquid chromatography and tandem mass spectrometry, and was applied to determine compounds with acidic and basic properties from environmental samples, such as river water and effluent wastewater samples, with excellent selectivity and matrix effect values below -30% and apparent recovery results ranging from 52% to 105% for most of the compounds. The analytical method was validated for environmental water samples and used in the analysis of samples in which some of the target compounds were found at ng L-1 concentration levels.

Weak anion-exchange mixed-mode materials to selectively extract acidic compounds by stir bar sorptive extraction from environmental waters.

In this study, the first example of a polytetrafluoroethylene (PTFE)-based magnet coated with weak anion exchange (WAX) monolith as novel support for stir bar sorptive extraction (SBSE) is presented. Firstly, the PTFE magnets were properly modified and vinylized in order to immobilize polymer monoliths onto its surface. Then, a glycidyl methacrylate monolith was prepared and modified with ethylenediamine (EDA) to create weak anion exchanger via ring opening reaction of epoxy groups. The prepared covalently immobilized EDA-modified monoliths onto PTFE magnet exhibited good stability and reusability. Application of resulting material as stir bar for SBSE was investigated for a series of acidic compounds that includes acesulfame, saccharin, diclofenac or ibuprofen, among others as target compounds. Firstly, the SBSE conditions were optimized to promote the WAX interactions with the target compounds achieving recoveries from 37 to 75% and enable the selective extraction of these compounds as it provided values of% matrix effect from 17 to -13% when they were determined by SBSE followed by liquid chromatography - tandem mass spectrometry. The analytical methodology, was then validated and applied for the determination of the target solutes in environmental water samples, which were found at concentration up to 2500 ng L-1 in river waters.

Presence of emerging organic contaminants and solvents in schools using passive sampling.

In this study, we report on the applicability of passive sampling with Carbopack X adsorbent tubes followed by thermal desorption gas-chromatography-mass spectrometry (TD-GC-MS) to monitor the concentrations of emerging organic contaminants (EOCs) and solvents in ten indoor environments in a conventional and a vocational training school. However, if passive sampling is to be used as a reliable sampling technique, a specific diffusive uptake rate is required for each target compound. Accordingly, the aim of the present study was twofold. The first was to determine the experimental diffusive uptake rates of the target EOCs and solvents in one of the sampling sites of the vocational training school using Carbopack X adsorbent tubes and active sampling as the reference technique. The results showed experimental diffusive uptake rates between 0.46 mL min-1 and 0.94 mL min-1 with RSD % below 5% for the 28 target compounds. The second was to apply the uptake rates obtained experimentally to determine EOCs and solvents in schools. The monitoring results showed that solvents were ubiquitous throughout the conventional school with a concentrations range between 51.93 µg m-3 and 164.6 µg m-3, while EOCs were detected to a lesser extent. Moreover, the concentrations of EOCs in the vocational training school were much higher than those in the conventional school with concentrations of up to 562.9 µg m-3 for solvents and 344.3 µg m-3 for acrylate polymer monomers. After actively sampling for seven days in each school, we concluded that the concentrations of EOCs and solvents found are mostly linked to cleaning products (conventional school) and the activities carried out in the classroom (vocational training school).

The embodiment of wastewater data for the estimation of illicit drug consumption in Spain.

Data obtained from wastewater analysis can provide rapid and complementary insights in illicit drug consumption at community level. Within Europe, Spain is an important country of transit of both cocaine and cannabis. The quantity of seized drugs and prevalence of their use rank Spain at the top of Europe. Hence, the implementation of a wastewater monitoring program at national level would help to get better understanding of spatial differences and trends in use of illicit drugs. In this study, a national wastewater campaign was performed for the first time to get more insight on the consumption of illicit drugs within Spain. The 13 Spanish cities monitored cover approximately 6 million inhabitants (12.8% of the Spanish population). Untreated wastewater samples were analyzed for urinary biomarkers of amphetamine, methamphetamine, MDMA, cocaine, and cannabis. In addition, weekend samples were monitored for 17 new psychoactive substances. Cannabis and cocaine are the most consumed drugs in Spain, but geographical variations showed, for instance, comparatively higher levels of methamphetamine in Barcelona and amphetamine in Bilbao, with about 1-fold higher consumption of these two substances in such metropolitan areas. For amphetamine, an enantiomeric profiling was performed in order to assure the results were due to consumption and not to illegal dumping of production residues. Furthermore, different correction factors for the excretion of cannabis were used to compare consumption estimations. All wastewater results were compared with previously reported data, national seizure data and general population survey data, were a reasonable agreement was found. Daily and yearly drug consumption were extrapolated to the entire Spanish population with due precautions because of the uncertainty associated. These data was further used to estimate the retail drug market, where for instance cocaine illicit consumption alone was calculated to contribute to 0.2-0.5% of the Spanish gross domestic product (ca. 3000-6000 million Euro/year).

Simple method for determining phthalate diesters and their metabolites in seafood species using QuEChERS extraction and liquid chromatography-high resolution mass spectrometry.

In this article we describe a new and simple analytical method based on the Quick, Easy, Cheap, Effective, Rugged and Safe technique followed by dispersive solid-phase extraction clean-up with C18 and Lipifiltr® and LC-HRMS for simultaneously extracting six phthalate diesters and six of their metabolites (phthalate monoesters) from highly consumed seafood species. The method was validated for seafood with high and low lipid contents. Apparent recoveries were up to 79% for all compounds. Matrix effect values ranged from -8 to -48% for all compounds in both types of matrices. Method limits of detection were 1-25 ng g-1 dry weight (d.w.) for most compounds. Five seafood species were analysed using this method, and several phthalate diesters and monoesters were successfully quantified. Phthalate diesters were found at concentrations of up to 982 ng g-1 (d.w.) and phthalate monoesters were found at concentrations of up to 178 ng g-1 (d.w.).

Assessing population exposure to phthalate plasticizers in thirteen Spanish cities through the analysis of wastewater.

Phthalates are widely used plasticizers that produce endocrine-disrupting disorders. Quantifying exposure is crucial to perform risk assessments and to develop proper health measures. Herein, a wastewater-based epidemiology approach has been applied to estimate human exposure to six of the mostly used phthalates within the Spanish population. Wastewater samples were collected over four weekdays from seventeen wastewater treatment plants serving thirteen cities and ca. 6 million people (12.8 % of the Spanish population). Phthalate metabolite loads in wastewater were transformed into metabolite concentrations in urine and into daily exposure levels to the parent phthalates. Considering all the sampled sites, population-weighted overall means of the estimated concentrations in urine varied between 0.7 ng/mL and 520 ng/mL. Very high levels, compared to human biomonitoring data, were estimated for monomethyl phthalate, metabolite of dimethyl phthalate. This, together with literature data pointing to other sources of this metabolite in sewage led to its exclusion for exposure assessments. For the remaining metabolites, estimated concentrations were closer to those found in urine. Their 4-days average exposure levels ranged from 2 to 1347 µg/(day∙inh), exceeding in some sites the daily exposure thresholds set for di-i-butyl phthalate and di-n-buthyl phthalate by the European Food Safety Authority.

Assessing alcohol consumption through wastewater-based epidemiology: Spain as a case study.

BACKGROUND: In this study, an alternative and complementary method to those approaches currently used to estimate alcohol consumption by the population is described. This method, known as wastewater-based epidemiology (WBE), allows back-calculating the alcohol consumption rate in a given population from the concentrations of a selected biomarker measured in wastewater. METHODS: Composite (24-h) wastewater samples were collected at the inlet of 17 wastewater treatment plants located in 13 Spanish cities for seven consecutive days in 2018. The sampled area covered 12.8% of the Spanish population. Wastewater samples were analyzed to determine the concentration of ethyl sulfate, the biomarker used to back-calculate alcohol consumption. RESULTS: Alcohol consumption ranged from 4.5 to 46 mL/day/inhabitant. Differences in consumption were statistically significant among the investigated cities and between weekdays and weekends. WBE-derived estimates of alcohol consumption were comparable to those reported by its corresponding region in the Spanish National Health Survey in most cases. At the national level, comparable results were obtained between the WBE-derived annual consumption rate (5.7 ± 1.2 L ethanol per capita (aged 15+)) and that reported by the National Health Survey (4.7 L ethanol per capita (aged 15+)). CONCLUSIONS: This is the largest WBE study carried out to date in Spain to estimate alcohol consumption rates. It confirms that this approach is useful for establishing spatial and temporal patterns of alcohol consumption, which could contribute to the development of health care management plans and policies. Contrary to established methods, it allows obtaining information in a fast and relatively economical way.

Microporous polymer microspheres with amphoteric character for the solid-phase extraction of acidic and basic analytes.

Solid-phase extraction (SPE) is a widely-used and very well-established sample preparation technique for liquid samples. An area of on-going focus for innovation in this field concerns the development of new and improved SPE sorbents that can enhance the sensitivity and/or the selectivity of SPE processes. In this context, mixed-mode ion-exchange sorbents have been developed and commercialised, thereby allowing enhanced capacity and selectivity to be offered by one single material. The ion-selectivity of these materials is such that either anion-exchange or cation-exchange is possible, however one limitation to their use is that more than one sorbent type is required to capture both anions and cations. In this paper, we disclose the design, synthesis and exploitation of a novel SPE sorbent based on microporous polymer microspheres with amphoteric character. We show that it is possible to switch the ion-exchange retention mechanism of the sorbent simply by changing the pH of the loading solution; anion-exchange dominates at low pH, cation-exchange dominates at high pH, and both mechanisms can contribute to retention when the polymer-bound amphoteric species, which are based on the α-amino acid sarcosine (N-methylglycine), are in a zwitterionic state. This is an interesting and useful feature, since it allows distinctly different groups of analytes (acids and bases) to be fractionated using one single amphoteric sorbent with dual-functionality. The sarcosine-based sorbent was applied to the SPE of acidic, basic and amphoteric analytes from ultrapure water, river water and effluent wastewater samples. Under optimised conditions (loading 100 mL of sample at pH 6, washing with 1 mL of MeOH and eluting with an acidic or basic additive in MeOH) the recoveries for most of the compounds were from 57% to 87% for river water and from 61% to 88% for effluent wastewater. We anticipate that these results will lay the basis for the development of a new family of multifunctional sorbents, where two or more separation mechanisms can be embedded within one single, bespoke material optimised for application to challenging chemical separations to give significant selectivity advantages over essentially all other state-of-the-art SPE sorbents.

Enantiomeric determination of cathinones in environmental water samples by liquid chromatography-high resolution mass spectrometry.

The enantiomeric determination of chiral drugs in the environment is of emerging concern since their enantiomers often exhibit stereoselectivity in environmental occurrence, fate and toxicity. In this study a method based on solid-phase extraction followed by chiral liquid chromatography and high-resolution mass spectrometry has been developed for the enantiomeric determination of a group of cathinones in river water and effluent wastewater. The enantioseparation was carried out using a Chiralpak CBH column in reversed-phase mode, and optimised by evaluating the effects of flow rate, buffer concentration and organic modifier. Under optimal conditions, good enantioseparations (Rs ≥1.2) were achieved for all the analytes. Two mixed-mode cation-exchange sorbents (Oasis WCX and Oasis MCX) in solid-phase extraction were evaluated in river water. Oasis MCX sorbent showed better performance with apparent recoveries ranging from 57 to 91% and matrix effect ranging from -10 to 15%. It is worth noting that a shifting of retention times and loss of enantioresolutions in environmental water samples was observed for all the analytes when the Oasis WCX sorbent was used. The method was validated with river water and effluent wastewater samples and its overall performance was satisfactory. The method quantification limits for all the analyte enantiomers ranged from 1.0 to 2.9 ng/L in river water, and from 2.3 to 6.0 ng/L in effluent wastewater. The repeatability and reproducibility values, expressed as% relative standard deviation (n = 5) were less than 15%. The method was then applied to the analysis of river water and effluent wastewater. The racemic methylone and methedrone (EF=0.49 and 0.46, respectively) were detected at low ng/L in some of the river water samples.