Occurrence and health risk assessment of PFAS and possible precursors: a case study in a drinking water treatment plant and bottled water (south Catalonia, Spain).

The presence of PFAS in drinking water may pose a serious threat to human health. This study aims to determine the levels of these compounds and their precursors in water samples from a drinking water treatment plant (DWTP) located in l'Ampolla (Spain) and to assess their fate. Additionally, ten Spanish bottled waters were analyzed to compare the occurrence of PFAS in the mentioned matrices and in drinking water. Off-line solid phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was applied to determine 26 PFAS and PFAS precursors after a total oxidizable precursor assay. The analytical method presents low quantification limits (0.25-5 ng/L). A total PFAS concentration of up to 16 ng/L in all the DWTP samples was obtained, and 6:2 FTS was the only precursor detected. Results are close to the quantification limits, resulting in a high degree of uncertainty, and for this, it is difficult to evaluate the DWTP PFAS removal efficiency. Regarding bottled water, total PFAS concentration found was up to 12 ng/L in one of ten samples, with no precursors detected. Exposure assessment revealed that there is no risk associated with the ingestion of the samples analyzed. Moreover, there were no differences in terms of risk between drinking water from l'Ampolla DWTP and bottled water.

Development of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of 40 Drugs of Abuse in Human Urine: Application to Real Cases.

Drugs of abuse are constantly evolving, while new synthetized substances are constantly emerging to avoid regulations. However, traditional drugs such as cocaine and amphetamine are still two of the most consumed drugs in the world. It is important, therefore, to provide suitable multiresidue methods for determining a wide range of drugs for use in toxicological and forensic analyses. The aim of this study is to develop a method for determining several families of drugs of abuse, including classic drugs, new psychoactive substances and some of their metabolites, in urine by liquid chromatography-tandem mass spectrometry. Urine is one of the most common biological matrices used in drug analysis because of its easy collection and a wide window of detection. In this study, we used solid-phase extraction to remove interferences and extract analytes from urine. Four different mixed-mode cation-exchange commercial sorbents were evaluated. The best results, in terms of apparent recoveries, were achieved with one of the strong cationic sorbents, ExtraBond SCX. The method achieved detection limits from 0.003 to 0.500 ng/mL and quantification limits from 0.050 to 1.500 ng/mL, which are suitable for determining these compounds at the usual levels found in the urine of drug users. The applicability of this method was demonstrated by analyzing real urine specimens from women following a detoxification program. Our results showed that the drug most consumed was cocaine, since it was detected in most urine specimens together with its main metabolite, benzoylecgonine. The polyconsumption of drugs from different families was also observed in some urine samples analyzed.

Comparison of different chiral selectors for the enantiomeric determination of amphetamine-type substances in human urine by solid-phase extraction followed by capillary electrophoresis-tandem mass spectrometry.

The present study develops a method for the enantioseparation of a group of amphetamines and their metabolites in urine by CE coupled to MS/MS (CE-MS/MS). Amphetamines present a chiral center and thus two enantiomers, which is important from a toxicological point of view because they may have different pharmacokinetic and pharmacological properties. It is therefore essential to find suitable methods to distinguish both enantiomers. Today the use of CE is becoming more important in this field since, with the simple addition of a chiral selector to the background electrolyte, the enantioseparation can easily be achieved. However, when CE is coupled to MS, the use of volatile chiral selectors and compatible background electrolytes or other strategies such as the countercurrent migration approach are required to avoid contamination of the ion source from nonvolatile species. In the present study, we use the latter strategy to evaluate six different chiral selectors using CE-MS/MS. As a sample pre-treatment, two cationic-exchange sorbents-Oasis WCX and Oasis MCX-are compared for the urine pre-treatment. Using this method, it was possible to achieve the complete chiral separation of the amphetamines under study with detection limits ranging between 0.8 and 1.5 ng/mL and method quantification limits between 2.0 and 8.0 ng/mL. Matrix-matched calibration curves up to 150 ng/mL were used to cover the usual concentration ranges at which amphetamines have generally been found in toxicological and forensic analyses.

Role of lithology in the presence of natural radioactivity in drinking water samples from Tarragona province.

One hundred and ninety-six drinking water samples from the different regions of Tarragona province (Catalonia, Spain) were analysed to determine the gross alpha and beta activity. Individual alpha emitting isotope activities were also determined to evaluate a possible relationship between their radiological content and the lithological and hydrogeological formations present in the studied area. The results obtained showed that approximately 23% of the analysed samples, mainly from five of the evaluated regions, had a gross alpha index exceeding the parametric value of 0.1 Bq/L for waters intended for human consumption according to the current legislation. This could be related to the presence of natural radionuclides in these water samples. The differences between the radiological content in these samples could be related to the different lithological conditions of the areas included in this study. High activity levels of 234U, 238U, 224Ra, 226Ra and 228Ra were detected in specific samples, mainly from granitic and carbonate areas. This research also focuses on evaluating the radiological risk associated with water ingestion. In this regard, consuming 95.5% of the drinking water samples analysed would not imply a health risk to the population as the annual effective doses calculated were below 0.1 mSv/year. There was only one sample that exceeded this level with a value of 0.33 mSv/year. 226Ra activity concentration was the radionuclide that mainly contributed to this dose.

Enantiodetermination of R,S-3,4-methylenedioxypyrovalerone in urine samples by high pressure in-line solid-phase extraction capillary electrophoresis-mass spectrometry.

This study presents for the first time an in-line solid-phase extraction capillary electrophoresis-mass spectrometry (SPE-CE-MS) method for the enantiodetermination of drugs of abuse in urine samples. The enantioseparation of R,S-3,4-methylenedioxypyrovalerone (R,S-MDPV) was achieved with a 10 mM ammonium acetate BGE (pH 7) that contained 0.5% (m/v) of sulphated-α-CD as chiral selector. At these pH conditions, this CD was negatively charged, which prevented its entrance into the mass spectrometer since it migrates in the opposite direction. To improve sensitivity, an in-line SPE-CE-MS method using high pressure for sample introduction (i.e. 20 min at 3 bars) was developed. Furthermore, the conditioning procedure and the first part of the electrophoretic separation were performed by switching off the nebulizer gas and the ionization source voltage to avoid non-volatile contaminant arrival into the mass spectrometer. The developed methodology was validated by analyzing urine samples, which required a very simple liquid-liquid extraction (LLE) sample pretreatment. Linearity ranged from 30 to 250 ng mL-1, limit of detection (LOD) was 10 ng mL-1, relative standard deviation (RSD) values were below 10.5% in terms of intra-day and inter-day precision and the relative error values were below 9% for peak areas accuracy.

A Fast Analytical Method for Determining Synthetic Cathinones in Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry.

In this paper, we present a method for simultaneously determining 11 synthetic cathinones in oral fluid (OF) by liquid chromatography-tandem mass spectrometry. Synthetic cathinones, a wide variety of which are available on the market, are constantly evolving. It is therefore important to provide efficient methods for determining cathinones in different matrices. A common matrix for detecting recent drug intake is OF, which can easily be collected using one of numerous commercial devices. Most methods aimed at determining drugs in biological samples such as OF require labor-intensive and time-consuming sample-preparation steps. However, the pretreatment of complex samples is often a challenge in the development of a method. For this reason, in this paper, we present a simple, easy-to-handle alternative that uses a Salivette® device and pretreats the sample in the same device. Matrix-matched calibration curves were used to cover the concentration range at which these substances are usually present in the OF from drug consumers. The method detection limits ranged from 0.003 to 0.03 ng/g, and the method quantification limits were set at 0.075 ng/g. This is a simple, rapid and sensitive method with good potential for determining recent drug consumption in OF.

Field-amplified sample injection combined with CE for the enantiodetermination of cathinones in urine samples.

This work presents a capillary electrophoresis methodology for the enantiodetermination of cathinones in urine employing a liquid-liquid extraction sample pretreatment. The cathinones were enantioseparated by adding a mixture of 8 mM 2-hydroxypropyl ß-cyclodextrin and 5 mM ß-cyclodextrin to the background electrolyte, which consists of 70 mM of monosodium phosphate aqueous solution at pH 2.5. Field-amplified sample injection was used as preconcentration strategy to improve the sensitivity. We studied various parameters that affect this stacking strategy, in particular, the sample solvent and its pH, the presence or absence of a low conductivity solvent plug introduced before the sample injection, the nature and volume of this plug, and the voltage and time of the electrokinetic injection of the sample. The optimum conditions were achieved by injecting a plug of isopropanol:H2 O 50/50 at 50 mbar for 5 s prior to the electrokinetic injection of the sample prepared in an aqueous solution of HCl 10-6  M. The sensitivity enhancement factors were from 562 to 601 in terms of peak area and from 444 to 472 in terms of peak height. The method was validated by analyzing spiked urine samples, obtaining a linear range of 25 to 1000 ng/mL and limits of detection ranging from 15 to 45 ng/mL.

Enantioselective determination of cathinones in urine by high pressure in-line SPE-CE.

This work presents a strategy based on the in-line coupling of SPE and CE for the chiral determination of cathinones (R,S-mephedrone, R,S-4-methylephedrine, and R,S- methylenedioxypyrovalerone) in urine samples, using a sample pretreatment based on liquid-liquid extraction. The chiral separation of the compounds is achieved by adding a mixture of 8 mM 2-hydroxypropil ß-CD and 5 mM ß-CD to the BGE, which consists of 70 mM of monosodium phosphate aqueous solution at pH 2.5. Oasis HLB was the selected sorbent for the in-line SPE device, and to reduce analysis time and LODs, several parameters affecting the in-line SPE system were evaluated, such as pressure and time of sample injection and dimensions of the SPE device. The highest preconcentration factors were achieved by using 3 bar of injection pressure for 20 min with an in-line SPE device of 2 mm length and 150 µm of i.d. The developed method was applied to determine the presence of the compounds in spiked urine samples. The LODs obtained were between 3 and 8 ng/mL, and these levels were below the usual concentrations at which these drugs are present in urine from cathinone abusers. Thus, the optimized method has the potential to be applied for toxicological and forensic purposes.

Sensitivity Enhancement in Capillary Electrophoresis Using Magnetic Particles as Solid-Phase Extraction Sorbents for the Determination of Drugs of Abuse in Urine.

Over the last few years, different types of magnetic particles have been investigated and successfully used in sample preparation, of which iron oxides are the most popular, due to their low price and low toxicity. For analytical purposes, these particles have always been modified and functionalized with different materials to improve their stability and introduce new surface properties. Here we describe the preparation of silica-coated iron oxide particles functionalized with C18 and their application as solid-phase extraction sorbents coupled in-line with capillary electrophoresis for determining drugs of abuse in human urine.

Findings in the hair of drug abusers using pressurized liquid extraction and solid-phase extraction coupled in-line with capillary electrophoresis.

A suitable method has been developed and validated for simultaneously determining cocaine and its major metabolite, benzoylecgonine, 6-acetylmorphine, codeine, morphine and the methadone enantiomers in human hair samples by the in-line coupling between SPE and CyD-assisted CE with a previous sample pretreatment procedure based on pressurized liquid extraction. Optimal separation was achieved on a fused silica-capillary of 50µm i.d. and 80cm total length using 11mM α-CyD in an aqueous solution of 80mM sodium phosphate at pH 2.5 as the separation medium and an applied voltage of 30kV. The SPE-CE device consisted of a short length of capillary packed with Oasis HLB sorbent, which was inserted near to the inlet end of the CE capillary. Several parameters affecting the in-line preconcentration were evaluated. The LOQs reached for hair samples were in the range of 0.3-2.5ng/mg with satisfactory analytical precision in both intraday and day-to-day experiments (RSDs <13%). Relative recoveries greater than 80% were obtained. The method has successfully been applied to the determination of these drugs of abuse in segmented hair from drug abusers who were undergoing methadone maintenance treatment. The results were consistent with the patients' statements, indicating that the method established herein can be used for verifying a history of drug abuse.

Enantioselective determination of cathinone derivatives in human hair by capillary electrophoresis combined in-line with solid-phase extraction.

A suitable method has been developed and validated for the chiral separation and determination of R,S-mephedrone and one of its metabolites, R,S-4-methylephedrine, and R,S-methylenedioxypyrovalerone (R,S-MDPV) in human hair samples by the in-line coupling between SPE and CD-assisted CE with a previous sample pretreatment procedure based on pressurized liquid extraction. Optimum separation was achieved on a fused silica-capillary of 50 µm id and 80 cm total length using 12 mg/mL ß-CD in an aqueous solution of 80 mM disodium phosphate at pH 2.5 as the BGE and an applied voltage of 30 kV. The SPE-CE device consists of a short length of a capillary of 2 mm packed with Oasis HLB sorbent, which was inserted near to the inlet end of the CE capillary. Several parameters affecting the in-line preconcentration were evaluated. The LOQs reached for hair samples were 0.05 ng/mg for the enantiomers of mephedrone and its metabolite, and 0.40 ng/mg for the enantiomers of MDPV. The RSDs (%) obtained in intra- and interday studies were less than 10% and the relative recoveries were greater than 80%. The method established in this paper is advantageous for its simplicity, overall analysis time and ability to provide information of both enantiomers of a chiral drug in hair samples.

Capillary electrophoresis combined in-line with solid-phase extraction using magnetic particles as new adsorbents for the determination of drugs of abuse in human urine.

A simple approach is presented based on the in-line coupling between magnetic particles-based SPE and CE. Silica-coated iron oxide particles functionalized with C18 were successfully synthesized and used as a reverse-phase sorbent for in-line SPE-CE. Magnets were used to locally immobilize these sorbents inside the capillary. Four drugs of abuse were preconcentrated and determined in urine samples using the developed method with a simple pretreatment procedure based on LLE. Several parameters affecting the preconcentration were evaluated. The obtained results show that this strategy enhanced detection sensitivity in the range of 125-700-fold compared with CE without preconcentration. The developed method provides LODs (S/N = 3) for standard samples in the range of 0.5-20 ng/mL with satisfactory analytical precision, in both intraday and day-to-day experiments (RSDs <20%). The LODs (S/N = 3) reached for urine samples were in the range of 20-50 ng/mL. Relative recoveries greater than 75.9% were obtained. The established method has been applied to the analysis of drugs of abuse in urine samples from drug abusers.

Single-drop microextraction combined in-line with capillary electrophoresis for the determination of nonsteroidal anti-inflammatory drugs in urine samples.

This study describes a method to determine nonsteroidal anti-inflammatory drugs (NSAIDs) in urine samples based on the use of single-drop microextraction (SDME) in a three-phase design as a preconcentration technique coupled in-line to capillary electrophoresis. Different parameters affecting the extraction efficiency of the SDME process were evaluated (e.g. type of extractant, volume of the microdroplet, and extraction time). The developed method was successfully applied to the analysis of human urine samples with LODs ranging between 1.0 and 2.5 µg/mL for all of the NSAIDs under study. This method shows RSD values ranging from 8.5 to 15.3% in interday analysis. The enrichment factors were calculated, resulting 27-fold for ketoprofen, 14-fold for diclofenac, 12-fold for ibuprofen, and 44-fold naproxen. Samples were analyzed applying the SDME-CE method and the obtained results presented satisfactory recovery values (82-115%). The overall method can be considered a promising approach for the analysis of NSAIDs in urine samples after minimal sample pretreatment.

Determination of cocaine in abuser hairs by CE: monitoring compliance to a detoxification program.

BACKGROUND: Segmental hair analysis was performed to verify the cocaine withdrawal and compliance to the therapy of four cocaine abusers that were following a drug detoxification program. RESULTS/METHODOLOGY: Cocaine and its major metabolite, benzoylecgonine, were preconcentrated and determined by in-line SPE and CE with prior isolation of the analytes from the hair matrix by an overnight acidic incubation procedure. The LODs obtained for hair samples were 0.02 ng/mg for cocaine and 0.1 ng/mg for benzoylecgonine. CONCLUSION: Our results showed that the established method, in conjunction with a segmental hair analysis, is suitable for determining drug abuse histories, being very useful in forensic toxicological laboratories as well as in rehabilitation and addiction treatment programs.

In-line solid-phase extraction-capillary zone electrophoresis for the determination of barbiturate drugs in human urine.

The abuse of barbiturate drugs is widespread, and the development of methods for their efficient separation and quantification is needed. Three barbiturate drugs were preconcentrated and determined by in-line solid-phase extraction (SPE) capillary electrophoresis (CE) in urine samples. Different parameters affecting preconcentration were evaluated, such as the sample pH, the volume of the elution plug and the sample injection time. This strategy enhanced the detection sensitivity in the range of 170- to 1840-fold, compared with normal hydrodynamic injection. The method provides limits of detection (LODs) for standard samples in the range of 0.5 to 5 ng/mL with good repeatability and reproducibility values. The LODs obtained for urine samples were in the range of 5 to 60 ng/mL. The validation with human urine samples spiked with the studied compounds demonstrated the applicability of the optimized method. This method provides a reproducible and sensitive analysis of urine samples in the determination of barbiturates drugs.

Higher water temperature and incubation under aerobic and microaerobic conditions increase the recovery and diversity of Arcobacter spp. from shellfish.

Some Arcobacter species are considered emerging food-borne and waterborne pathogens, and shellfish have been suggested as one of their reservoirs. However, only a few studies have investigated the presence of Arcobacter in this kind of food. This study assesses the prevalence and diversity of Arcobacter spp. in shellfish by multiplex PCR (m-PCR) and culturing methods (under different atmospheric conditions) and evaluates the possible influence of environmental parameters (temperature, salinity, and harvesting bay). Arcobacter was detected by m-PCR and/or culturing in 61 (29.9%) of 204 shellfish samples. Of the positive samples by culturing, 41.1% were obtained under only aerobic incubation conditions, while 23.2% were obtained under only microaerobic conditions. Of 476 investigated isolates, 118 belonged to different enterobacterial repetitive intergenic consensus (ERIC)-PCR genotypes (strains) and to 11 different species. This study shows the highest diversity of Arcobacter species ever observed in samples from any origin. The most prevalent species was Arcobacter butzleri (60.2%), followed by Arcobacter molluscorum (21.2%). The prevalence of Arcobacter was significantly higher during the summer than in other seasons, being associated with an increase in water temperature. Results confirm that shellfish are a reservoir for a remarkable diversity of Arcobacter spp.

Electrokinetic supercharging in CE for the separation and preconcentration of barbiturate drugs in urine samples.

Three barbiturate drugs, barbital, phenobarbital, and secobarbital were separated and analyzed by electrokinetic supercharging. The influence of different parameters on electrokinetic supercharging performance was evaluated using both univariated and multivariated optimization processes. The parameters studied were sample pH, concentration, and length of the leading and terminating electrolytes, electrokinetic injection of the sample and composition and hydrodynamic injection of the solvent plug. The leading electrolyte (50 mM NaCl) was hydrodynamically injected (50 mbar × 120 s) prior to the sample that was adjusted to pH 9.6 and electrokinetically injected at -8.5 kV for 300 s. The terminating electrolyte (100 mM of 2-(cyclohexylamino) ethanesulphonic acid) was then hydrodynamically injected (50 mbar × 140 s). The results showed that this strategy enhanced detection sensitivity around 1050-fold compared with normal hydrodynamic injection, providing detection limits ranging between 1.5 and 2.1 ng/mL for standard samples with good repeatability in terms of peak area (values of relative standard deviation, %RSD < 3). The applicability of the optimized method was demonstrated by the analysis of human urine samples spiked with the studied compounds at different concentration levels and further liquid-liquid extraction step. The estimated detection limits obtained in the urine samples extract ranged between 8 and 15 ng/mL.

Evaluation of the use of reverse osmosis to eliminate natural radionuclides from water samples.

The objective of drinking water treatment plants (DWTP) is to supply the population with tap water that is in optimal condition and in compliance with water quality regulations. In the DWTP of L'Ampolla (Tarragona, Spain), slightly high values of gross alpha activity and the amount of salts in the raw water have been observed. Conventional treatment has reduced these levels only minimally. This study tested a tertiary treatment based on reverse osmosis is tested in an industrial pilot plant (240 m3/day) The efficiency of this pilot plant to reduce the gross alpha and beta activities and the activity of some individual radioisotopes (U(238), U(234), U(235) and Ra(226)) was tested. Results showed that the elimination of alpha emitters was greater than 90%, whereas the elimination of beta emitters was about 35%. Overall, the data provided evidence that the pilot plant is effective for removing different radionuclides that can be present in the incoming water treated. Therefore, tertiary treatment based on reverse osmosis has a positive effect in water quality.

Determination of UV filters in river water samples by in-line SPE-CE-MS.

The use of SPE coupled in-line to CE using electrospray MS detection (in-line SPE-CE-ESI-MS) was investigated for the preconcentration and separation of four UV filters: benzophenone-3, 2,2-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone and 2-phenylbenzimidazole-5-sulphonic acid. First, a CE-ESI-MS method was developed and validated using standard samples, obtaining LODs between 0.06 µg/mL and 0.40 µg/mL. For the in-line SPE-CE-ESI-MS method, three different sorbents were evaluated and compared: Oasis HLB, Oasis MCX, and Oasis MAX. For each sorbent, the main parameters affecting the preconcentration performance, such as sample pH, volume, and composition of the elution plug, and sample injection time were studied. The Oasis MCX sorbent showed the best performance and was used to validate the in-line SPE-CE-ESI-MS methodology. The LODs reached for standard samples were in the range between 0.01 and 0.05 ng/mL with good reproducibility and the developed strategy provided sensitivity enhancement factors between 3400-fold and 34 000-fold. The applicability of the developed methodology was demonstrated by the analysis of UV filters in river water samples.

Different strategies for the preconcentration and separation of parabens by capillary electrophoresis.

Several strategies, namely, large volume sample stacking (LVSS), field-amplified sample injection (FASI), sweeping, and in-line SPE-CE, were investigated for the simultaneous separation and preconcentration of a group of parabens. A BGE consisting of 20 mM sodium dihydrogenphosphate (pH 2.28) and 150 mM SDS with 15% ACN was used for the separation and preconcentration of the compounds by sweeping, and a BGE consisting of 30 mM sodium borate (pH 9.5) was used for the separation and preconcentration of the compounds by LVSS, FASI, and in-line SPE-CE. Several factors affecting the preconcentration process were investigated in order to obtain the maximum enhancement of sensitivity. The LODs obtained for parabens were in the range of 18-27, 3-4, 2, and 0.01-0.02 ng/mL, and the sensitivity evaluated in terms of LODs was improved up to 29-, 77-, 120-, and 18,400-fold for sweeping, LVSS, FASI, and in-line SPE-CE, respectively. These preconcentration techniques showed potential as good strategies for focusing parabens. The four methods were validated with standard samples to show the potential of these techniques for future applications in real samples, such as biological and environmental samples.