Ultrasound-assisted extraction as an easy-to-perform analytical methodology for monitoring ibuprofen and its main metabolites in mussels.

Non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to be the main pharmaceutical class accumulated in seafood. Among them, ibuprofen (IBU) is of special concern as it is used worldwide to treat common pain, does not require a medical prescription, it is often taken in a high daily dose, and has been reported to cause potential adverse effects on aquatic organisms. IBU is highly transformed into hydroxy- and carboxy-metabolites and/or degradation products generated not only after its administration but also during wastewater treatment or in the environment. These compounds can be present in the environment at higher concentrations than IBU and present higher toxicity. In this work, a low-cost and affordable routine analytical method was developed and validated for the first-time determination of IBU and its main metabolites in mussels. The method is based on ultrasound-assisted extraction (UAE), clean-up by dispersive solid-phase extraction (d-SPE) and analytical determination by liquid chromatography-tandem mass spectrometry. Box-Behnken experimental design was used for method optimisation to better evaluate the influence and interactions of UAE and d-SPE variables. Extraction recoveries were in the range from 81 to 115%. Precision, expressed as relative standard deviation, was lower than 7%. Method detection limits were in the range from 0.1 to 1.9 ng g-1 dry weight. The method was successfully applied to wild mussels.

Occurrence of the main metabolites of the most recurrent pharmaceuticals and personal care products in Mediterranean soils.

The use of sewage sludge and wastewater in agricultural lands provide contaminants to soils. As a result, a large number of contaminants can be present in soils. Among others, pharmaceuticals and personal care products (PPCPs) are two of the most studied families of emerging contaminants in wastewater. However, there is scarce information about their behaviour in soils. Occurrence, fate and behaviour in soils of metabolites are even less known. In this work, the degradation of most recurrent PPCPs in the environment and their main metabolites has been evaluated using batch experiments in three typical Mediterranean soils. Batch experiments were carried out in a climatic chamber using spiked soils under Mediterranean climatic conditions. The studied compounds were five pharmaceutically active compounds (carbamazepine, ibuprofen, caffeine, sulfamethoxazole and diclofenac), two parabens (methylparaben and propylparaben) and twelve of their main metabolites. Studied PPCPs and metabolites showed different adsorption capacity onto the studied soils. As results, despite of the compounds were spiked at the same concentrations, different contents were measured at the beginning of the batch experiments. The soil 3 showed the lowest degradation rate for all studied compounds what could be related with the higher adsorption capacity of this soil. A decrease of the measured contents was observed for all studied compounds, except in the case of CBZ and EP-CBZ. No transformations of parent compounds into their metabolites or vice versa were observed, except in the case of Ibuprofen and its metabolites. Although the results showed overall short degradation times for the most of the compounds studied, the evaluation of the environmental risks of the PPCPs and their metabolites should not be underestimated.

Approach to the Dynamic of Carbamazepine and its Main Metabolites in Soil Contamination through the Reuse of Wastewater and Sewage Sludge.

The release of pharmaceutically active compounds to the soils through the application of sewage sludge and the irrigation with wastewater, or even with surface water, is constant. The adsorption of these compounds onto the soil is one of the key factors affecting their fate in the environment and their potential environmental risks. In this work, the adsorption of carbamazepine (CBZ) and its metabolites, 3-hydroxy-carbamazepine (3OH-CBZ), carbamazepine-10,11-dihydro-10,11-epoxide (EP-CBZ), and 10,11-dihydro-10-hydroxycarbamazepine (10OH-CBZ), in three Mediterranean soils was evaluated using single-solute and four-solute experiments. The highest adsorptions were measured for 3OH-CBZ, followed by CBZ, EP-CBZ, and 10OH-CBZ, in that order. A high influence of the physicochemical characteristics of the compounds, pH, and soil characteristics in the adsorption of the studied compounds was observed and corroborated by the statistical analysis of the results. Moreover, a good fit was observed in the three isotherm models evaluated (linear, Freundlich, and Langmuir) in single-solute experiments (R2 > 0.90). However, a decrease of the measured adsorptions and a worse fit to the isotherm models were observed in the case of multiple-solute experiments. This could be mainly due to the competition established between the studied compounds for the active sites of the soils.

Distribution of metals in sediments of the Guadiamar river basin 20 years after the Aznalcóllar mine spill: Bioavailability and risk assessment.

In April 1998, 6 million m3 of acid water and sludge were accidently spilled on to the Guadiamar riverbed (South of Spain). In this study, the long term distribution of Al, Cd, Cu, Fe, Mn, Pb, and Zn in the sediments of the Guadiamar river basin is described using fractionation analysis. Changes in the availability of metals from 2002 to 2018, covering a period of 20 years after the dam collapse, have been evaluated and their potential environmental risks have been examined. A substantial decrease in the concentrations of all the metals studied was observed, except Pb. However, the concentrations of Cu, Zn, and Pb remained higher than the background concentrations, which indicates a high influence of the mining activity, even in 2018. An increase of the residual fraction was observed from 2002 (47%) to 2018 (67%), which was mainly due to the mobilisation of metals from their oxidisable fraction to their residual fraction. Environmental risk assessment revealed a significant decrease in the risk associated with metals from 2002 to 2018, mainly due to the decrease of the metals concentration in the sediments over the year and to the lower availability of these metals in 2018. In 2002, the most challenging metals were Pb and Zn, whereas in 2018, Zn and Cd were the most problematic due to their toxicity and availability.

Selective pressurized extraction as single-step extraction and clean-up for the determination of organophosphate ester flame retardant in Citrus aurantium leaves by gas chromatography-tandem mass spectrometry.

In this work, an analytical method has been developed and validated for the determination of organophosphate esters (OPEs) in urban ornamental tree leaves. OPEs are flame retardants and plasticizers which are classified as health and environmental hazards substances. Their presence in urban air has been previously described. The method proposed in this work would allow the use of urban tree leaves as simple, cheap, and widely distributed in urban areas alternative to the existing active and passive sampler for sample collection. The method was based on sample treatment by selective pressurized liquid extraction (SPLE) and determination by gas chromatography with triple quadrupole mass spectrometry detector. After the optimization of the extraction solvent, the key parameters applied to SPLE (clean sorbent and sorbent amount applied for the sample clean-up, temperature, extraction cycles, and time) were optimized using a Box-Behnken response surface design. The method achieves high recoveries (higher than 60% for most of the target compounds), accuracies between 70 and 109%, and method detection and quantification limits ranged 0.05-4.96 ng/g dw (dry weight) and 0.15-14.4 ng/g dw, respectively. The method allowed the proper biomonitoring of OPE in tree leaves. Concentrations measured in analyzed samples were from 47.5 to 5477 ng/g dw (TEP). The most frequently detected compounds were triethyl phosphate tri-n-butyl phosphate, triphenyl phosphate, and tris(1-chloro-2-propyl)phosphate, while tris(2-ethylhexyl)phosphate was not detected in the analyzed samples. The proposed analytical method constitutes a starting point for the use of ornamental urban trees as passive sampler for the evaluation of OPE as air pollutants. Graphical Abstract.

Routine analytical method for monitoring the main metabolites for a recurrent group of parabens and pharmaceuticals in wastewater and tap water.

The presence of parabens and pharmaceuticals on the aquatic environment has been widely evaluated in the last years. Nevertheless, there is scarce information about the occurrence of their metabolites and/or degradation products in spite of the fact that they can be more toxic or more concentrated than their parent compounds. One of the main drawbacks for their monitoring is the lack of simple and reliable analytical methods for their routine determination. In this work, an analytical method has been developed and validated for the simultaneous extraction and determination of the main metabolites of the pharmaceuticals diclofenac, ibuprofen, sulfamethoxazole, carbamazepine and caffeine and of the parabens methylparaben and propylparaben and their parent compounds in wastewater and tap water samples. Sample extraction was carried out by conventional solid-phase extraction with OASIS HLB cartridges. Analytical determination was carried out by liquid chromatography-tandem mass spectrometry with electrospray ionization. Average accuracy was in the range from 66 to 120% in wastewater and from 86 to 120% in tap water. Precision, expressed as relative standard deviation, was lower than 17% for all the compounds. Method quantification limits were in the range from 1.0 to 33 ng L-1 in wastewater and from 0.5 to 28 ng L-1 in tap water. The method was applied to wastewater and tap water samples. None of the target compounds was detected in tap water whereas all of them were detected in wastewater. Concentrations of the metabolites were similar or higher than those of the parent compounds. Graphical abstract.

Determination of perfluorinated compounds, bisphenol A, anionic surfactants and personal care products in digested sludge, compost and soil by liquid-chromatography-tandem mass spectrometry.

A method for the determination of 23 emerging concern pollutants in digested sludge, compost and soil has been developed. Target pollutants include six perfluorinated compounds (5 perfluorocarboxylic acids and perfluorooctanesulfonic acid), the plasticizer bisphenol A, four anionic surfactants (sodium alkylsulfates), four preservatives (parabens), two antimicrobial agents (triclosan and triclocarban) and six UV-filters (benzophenones). Sample treatment was based on ultrasound-assisted extraction with 3 mL of methanol:acetic acid (95:5, v/v) and clean-up by dispersive solid-phase extraction (d-SPE) with C18. Analytical determination was carried out by liquid chromatography-tandem mass spectrometry. Extraction solvent, sonication time, number of extraction cycles and type and amount of d-SPE sorbent were optimized. Due to the physical-chemical properties of target compounds, and the high number of sample treatment variables involved, a Box-Behnken design was applied to method optimization. The method was validated by means of spiked samples. Method detection limits were in the range from 0.01 to 6.2 ng g-1 dry matter. Accuracy and precision were evaluated at three spike levels in each type of sample matrix. Accuracy, expressed as relative recovery, was in the range from 70% to 120% for most of the compounds and spike levels. Precision, expressed as relative standard deviation, was equal or below 21%. To the best of our knowledge, the proposed method constitute the first analytical method for multiclass determination of emerging pollutants in digested sludge, compost and soils.

Dispersive liquid-liquid microextraction as a new clean-up procedure for the determination of parabens, perfluorinated compounds, UV filters, biocides, surfactants, and plasticizers in root vegetables.

An analytical method based on ultrasound-assisted extraction and dispersive liquid-liquid microextraction (DLLME) clean-up has been developed and validated for the determination of 31 emerging pollutants in root vegetables. The target compounds were four preservatives, six perfluoroalkyl compounds, six UV filters, two biocides, eight anionic surfactants, three nonionic surfactants, and two plasticizers. The type and volume of the extraction solvent, those of the disperser solvent, the pH and NaCl content of the DLLME aqueous phase, the amount of sample, and the sonication time were optimized. Box-Behnken experimental design was applied to select the best extraction conditions. Matrix-matched calibration curves were used for quantification. Four internal standards were used to compensate for residual matrix effects. Good linearity (R2 > 0.990), accuracies (expressed as the relative recovery) of >82%, and precisions (expressed as the relative standard deviation) of <18% were achieved. Method quantification limits (MQLs), calculated from spiked samples as the concentrations corresponding to signal-to-noise ratios of 10, were in the range 0.1-25 ng g-1 dry weight (d.w.). MQL values for 26 of the 31 target compounds were lower than 5 ng g-1 d.w. The method was successfully applied to determine the target pollutants in carrots, potatoes, and turnips from a local market. To the best of our knowledge, the proposed method constitutes the first application of DLLME as a clean-up procedure for the multiresidue determination of emerging pollutants in vegetables. The method affords similar recoveries and method detection limits to previously reported methods but requires smaller solvent volumes and sample amounts and is less expensive.

Stir bar sorptive extraction and liquid chromatography-tandem mass spectrometry determination of polar and non-polar emerging and priority pollutants in environmental waters.

An analytical method based on stir bar sorptive extraction (SBSE) was developed and validated for the determination of environmental concern pollutants in environmental waters by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Target compounds include six water and oil repellents (perfluorinated compounds), four preservatives (butylated hydroxytoluene and three parabens), two plasticizers (bisphenol A and di(2-ethylhexyl)phthalate), seven surfactants (four linear alkylbenzene sulfonates, nonylphenol and two nonylphenol ethoxylates), a flame retardant (hexabromocyclododecane), four hormones, fourteen pharmaceutical compounds, an UV-filter (2-ethylhexyl 4-methoxycinnamate) and nine pesticides. To achieve the simultaneous extraction of polar and non-polar pollutants two stir bar coatings were tested, the classic polydimethylsiloxane (PDMS) coating and the novel ethylene glycol modified silicone (EG-silicone). The best extraction recoveries were obtained using EG-silicone coating. The effects of sample pH, volume and ionic strength and extraction time on extraction recoveries were evaluated. The analytical method was validated for surface water and tap water samples. The method quantification limits ranged from 7.0ngL-1 to 177ngL-1. The inter-day precision, expressed as relative standard deviation, was lower than 20%. Accuracy, expressed as relative recovery values, was in the range from 61 to 130%. The method was applied for the determination of the 48 target compounds in surface and tap water samples.