High resolution mass spectrometry (HRMS) determination of drugs in wastewater and wastewater based epidemiology in Cadiz Bay (Spain).

Multi-residue methods for the determination of the myriad of compounds of emerging concern (CECs) entering in the environment are key elements for further assessment on their distribution and fate. Here, we have developed an analytical protocol for the simultaneous analysis of 195 prescription, over-the-counter, and illicit drugs by using a combination of solid phase extraction (SPE) and determination by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method was applied to the analysis of influent sewage samples from 3 wastewater treatment plants (WWTPs) from Cadiz Bay (SW Spain), enabling the quantification of more than 100 pharmaceuticals, 19 of them at average concentrations higher than 1 µg L-1, including caffeine (92 µg L-1), paracetamol (72 µg L-1), and ibuprofen (56 µg L-1), as well as several illicit drugs (e.g., cocaine). Wastewater based epidemiology (WBE) was applied for 27 of the detected compounds to establish their consumption in the sampling area, which has been never attempted before. Caffeine, naproxen, and salicylic acid stood out because of their high consumption (638, 51, and 20 g d-1·1000pop-1, respectively). Regarding illicit drugs, cocaine showed the highest frequency of detection and we estimated an average consumption of 3683 mg d-1·1000pop-1 in Cadiz Bay. The combination of new HRMS methods, capable of discriminating thousands of chemicals, and WBE will allow for a more comprehensive characterization of chemical substances and their consumption in urban environments in the near future.

Quality by design optimization of a liquid chromatographic-tandem mass spectrometric method for the simultaneous analysis of structurally heterogeneous pharmaceutical compounds and its application to the rapid screening in wastewater and surface water samples by large volume direct injection.

This study focused on the Analytical Quality by Design (AQbD) optimization of the chromatographic separation and mass spectrometric detection of a wide group of structurally heterogeneous model pharmaceutical compounds (PhCs) and transformation products (TPs), chosen to cover the challenging issues of the co-presence of compounds characterized by (i) a wide range of physicochemical properties, (ii) the same mass transitions, and (iii) different ionisation modes. Italian consumption of PhCs were also considered as election criteria of target analytes. Octadecyl and pentafluorophenyl stationary phases, acetonitrile/methanol ratios and acidity of the eluents, column temperature, initial organic phase percentage, and elution gradient were investigated by AQbD, aiming at optimizing critical resolutions, sensitivities, and analysis time. Statistically significant models were obtained in most cases with fitting and cross-validation coefficients in the ranges of 0.681-0.998 and 0.514-0.967, respectively. After optimization, the analysis of target analytes was performed in a single chromatographic run, adopting a mixed acquisition mode based on scheduled acquisition windows comprising both single polarity and continuous polarity switching. For most investigated analytes the method provided detection limits in the sub-ng/L to low ng/L range, meeting for macrolides the sensitivity requested by the "Watch List" 2018/840/EU. The optimized method was applied to the direct injection analysis of PhCs and TPs in four wastewater treatment plant (WWTP) effluents and surface water (SW) samples collected in the receiving water bodies. Absolute values of matrix effect were found to be far higher than 20% for most target analytes in most samples. Seventeen PhCs and two TPs were quantified in at least one sample, at the wide concentration range of about 1-3200 ng/L. The most occurring PhCs in both WWTP effluents and SWs were levofloxacin (202-1239 and 100-830 ng/L), furosemide (865-3234 and 230-880 ng/L), ketoprofen (295-1104 and 270-490 ng/L), and ibuprofen (886-3232 and 690-1440 ng/L).

UV filters and UV stabilisers adsorbed in microplastic debris from beach sand.

Microplastics (MPs) in oceans adsorb different types of pollutants, which can negatively impact the food chain. The extensive use of personal care products (PCPs) has led to their ubiquitous environmental presence, and their partition between plastic matrices and surroundings is determined by their physico-chemical characteristics and environmental conditions. This work develops and applies a methodology to determine 12 UV filters (UVFs) and UV stabilisers (UVSs) in MPs collected in beach sand. The analyses were carried out by ultrasound-assisted extraction and ultrahigh-performance liquid chromatography with tandem mass spectrometry detection. The validated procedure was applied to MPs samples taken in sand samples from 13 beaches on the Canary Islands (Spain). The results showed the presence of 10 UV filters and UV stabilisers at concentrations between 1 and 4031 ng·g-1, where octocrylene was the most frequently found. The target analytes were present in all the sampling beaches.

An assessment of the concentration of pharmaceuticals adsorbed on microplastics.

In the last decade, microplastics (MPs) have become an increasing cause for concerning. These particles are scattered throughout seas and oceans and have the capability of transporting adsorbed pollutants as pharmaceutical compounds, which can cause toxic effects and be transferred along the food chain. The development, optimization and validation of a sensitive and reliable analytical procedure for the extraction and determination of ten common pharmaceuticals adsorbed on MPs is reported in this study. This method involves ultrasound-assisted extraction coupled with ultra-high-performance liquid chromatography and tandem mass spectrometry. All of the variables included in the extraction process, such as the extraction time and type and solvent volume, were studied and optimised. Under optimal conditions, good reproducibility and repeatability, with relative standard deviations lower than 15% in most cases, were obtained while limits of detection between 0.25 and 15.8 ng g-1 were achieved. Last, the method was applied to the analysis of samples collected from beaches in the Canary Islands (Spain). The results indicated the presence of several analytes adsorbed on MPs in concentrations ranging from 34.0 to 111 ng g-1.

Determination of 5-fluorocytosine, 5-fluorouracil, and 5-fluorouridine in hospital wastewater by liquid chromatography-mass spectrometry.

Chemotherapeutics are pharmaceutical compounds the occurrence of which in the environment is of growing concern because of the increase in treatments against cancer diseases. They can reach the aquatic ecosystems after passing through wastewater treatment plants without complete removal. One of the most frequently used chemotherapeutics is 5-fluorouracil which exhibits a strong cytostatic effect. In this paper, an analytical methodology was developed, validated, and applied to determine 5-fluorouracil, its precursor, 5-fluorocytosine, and its major active metabolite, 5-fluorouridine, in hospital wastewater samples. Due to the expected low concentrations after dilution and interferences present in such a complex matrix, a very selective and sensitive detection method is required. Moreover, an extraction method must be implemented prior to the determination in order to purify the sample extract and preconcentrate the target analytes at micrograms per liter concentration levels. Solid-phase extraction followed by liquid chromatography with tandem mass spectrometry was the combination of choice and all included parameters were studied. Under optimized conditions for wastewater samples analysis, recoveries from 63 to 108% were obtained, while intraday and interday relative standard deviations never exceeded 20 and 25%, respectively. Limits of detection between 61 and 620 ng/L were achieved. Finally, the optimized method was applied to samples from hospital wastewater effluents.

Cytostatic compounds in sludge and sediment: extraction and determination by a combination of microwave-assisted extraction and UHPLC-MS/MS.

Cytostatic compounds are an important group of micro-pollutants since they are used to kill cells or stop cell division. For this reason, they are also considered mutagenic. Several cytostatic compounds have been detected in hospital effluents, in the influents and effluents of wastewater treatment plants and even in river water. However, their detection in solid matrices is very scarce. In this work, we have developed a new procedure based on microwave-assisted extraction (MAE) for the extraction of cytostatic compounds from sludge and sediment before determination by ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). To develop this procedure, we have chosen a group of eight widely used cytostatic compounds and carried out a systematic experimental design to optimize the extraction conditions. Under these optimal conditions, the studied cytostatic compounds are extracted with good sensitivity, with recoveries ranging from 65 to 122% in sludge and recoveries varying between 49 and 109% in sediment, with the exception of etoposide, which has a lower recovery from these types of samples. The limits of detection were from 0.42 to 79.8 ng g-1 in sludge and from 0.10 to 87.5 ng g-1 in sediment. Intraday and interday relative standard deviations (RSDs) were below 15% and 18%, respectively, in both matrices at the tested concentrations. The total procedure was applied to samples of sludge taken from the main wastewater treatment plant (WWTP) of the island of Gran Canaria (Spain) and for sediment samples obtained close to the marine outfalls of different wastewater treatment plants for the same island. Graphical abstract.

Optimization and application of fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry for the determination of cytostatic drug residues in environmental waters.

Every year, hundreds of tons of organic pollutants reach the environment through effluents released from wastewater treatment plants worldwide, and many of these compounds have harmful effects on the aquatic ecosystem. A new class of emerging pollutants of high concern is cytostatic drugs, which are designed to treat different types of cancers by attacking cells. Environmental concentrations of cytostatic drugs are known to be in the range of ngL-1, and for this reason, it is imperative to develop analytical methods of extraction and preconcentration to allow for subsequent instrumental analysis of these drugs. In this work, a rapid, simple and green method for the analysis of seven cytostatic drug compounds that are commonly used in anti-cancer therapies was developed using a novel extraction process based on a powerful miniaturized technique, fabric phase sorptive extraction (FPSE) coupled to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The major parameters that affect the extraction process were optimized. The new method shows good linearity, with a relative standard deviation (RSD) of less than 12%. Relative recoveries higher than 40% were obtained for the studied compounds, and the detection limit of the method was within the values at which these compounds are usually found in environmental water (0.20ngL-1 to 80ngL-1). The Limit of Quantification ranged from 0.68 to 267ngL-1. Significant suppression of the signal due to the matrix effect, a common shortcoming attributed to interference from the extraction process as well as the use of ionization mode, was not observed. Subsequently, the method was applied to real wastewater samples from an effluent obtained from a hospital area and three wastewater treatment plants located in Gran Canaria Island, Spain.

Application of microwave-assisted extraction and ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis of sex hormones and corticosteroids in sewage sludge samples.

Hormonal compounds are a concern to the international community because they can affect the aquatic biota and are therefore considered to be endocrine-disrupting compounds. These compounds have lipophilic properties, so they tend to accumulate in solid matrices, such as sewage sludge. This work presents the optimization of a microwave-assisted extraction process combined with ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of 15 hormonal compounds in sludge samples. The proposed method has relative standard deviations below 23 %, good recoveries (over 71 %) for all compounds, detection limits that ranged from 1.1 to 7.9 ng g(-1) and quantification limits which ranged from 3.7 to 26.3 ng g(-1). The method was used to analyse sludge samples from four different wastewater treatment plants of Gran Canaria (Spain) with different wastewater treatments. 17ß-estradiol, 17α-ethynylestradiol, norgestrel and cortisone were detected in sludge samples at concentrations that ranged from 17.3 to 1.44 × 10(3) ng g(-1). The developed method permits the use of small quantities of sample and organic solvents, presents short extractions times and is the first one based on microwave-assisted extraction for the analysis of both sex hormones and corticosteroids.

Molecularly imprinted solid-phase extraction coupled with ultra high performance liquid chromatography and fluorescence detection for the determination of estrogens and their metabolites in wastewater.

Estrogens are an important class of endocrine-disrupting compounds, and their contamination of environmental waters through the effluents of wastewater treatment plants could have an important impact on aquatic biota, even at low concentrations. For this reason, the development of selective and sensitive extraction methodologies, which permit the identification and quantification of these compounds at trace level concentrations, is very important. In this study, a quantitative method based on molecularly imprinted solid phase extraction coupled to ultra high performance liquid chromatography with fluorescence detection has been developed. It has been used for the simultaneous determination of three estrogens and two of their metabolites in water samples from wastewater treatment plants. The method developed presents satisfactory limits of detection (between 0.18 and 0.45 ng·mL-1 ), good recoveries (higher than 60%) and low relative standard deviations (under 10%). The method was used to analyze wastewater from a veterinary hospital as well as influent and effluent samples of a wastewater treatment plant of Gran Canaria (Spain) The concentrations of the detected hormones ranged from 1.35 to 2.57 ng·mL-1 .