Dispersive Solid-phase Extraction Clean-up Research Articles

Ecological risk assessment of organochlorine pesticide residues in sediment samples from Lake Tana and Hayqe in Northwest Ethiopia

In most developing countries, including Ethiopia, the excessive use of toxic and persistent pesticides for agricultural and malaria control purposes poses a significant challenge. This study focuses on evaluating the concentration and ecological risks associated with organochlorine pesticides (OCPs) in the sediments of Lake Tana and Hayqe. Employing a laboratory-based cross-sectional approach, the residues of OCPs in sediment samples were extracted using the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method, followed by dispersive solid phase extraction cleanup (d-SPE) techniques and analyzed for 18 OCPs by gas chromatography coupled to tandem mass spectrometry (GC-MS). The risk Quotient (RQ) method was adopted for ecological risk assessments by using fish, daphnia, and algae as indicators. The concentration of OCPs ranged from 10.11 to 125.65 μg/kg and 10.96–45.17 μg/kg in Lake Tana and Hayqe, respectively. There was a statistically significant difference in the mean concentration of OCPs across the sampling sites in Lake Tana. Deltamethrin and lindane exhibit comparatively lower concentrations among the OCPs, whereas endrin, DDT, and their metabolites were the predominant pesticides in the study area, exceeding WHO and USEPA residue limits, except for endosulfan. Risk Quotient values ranged from 0.006 to 865.4 in Lake Tana and 0.005 to 729.9 in Lake Hayqe, indicating potential low to high ecological risks for aquatic organisms. High ecological risks are particularly evident in fish, daphnia, and algae species exposed to α and β-Endosulfan, DDT, and their metabolites, while specifically in daphnia, endrin poses high ecological risks. The ANOVA test revealed there were statistically significant differences (p-value <0.05) among sampling sites in Lake Tana and the mean values between Lake Tana and Lake Hayqe, underscoring the importance of addressing pesticide-related ecological concerns in the region.

Determination of polycyclic aromatic hydrocarbons, phthalate esters, alkylphenols and alkyphenol ethoxylates in sediment using simultaneous focused ultrasound solid–liquid extraction and dispersive solid-phase extraction clean-up followed by liquid chromatography

The study presents a simple and non-laborious method for the determination of 16 polycyclic aromatic hydrocarbons (PAHs), 2 phthalate esters (PEs), 2 alkylphenols (APs) and 4 alkylphenol ethoxylates (APEOs) in sediment. The method employs sample preparation combining focused ultrasound solid–liquid extraction (FUSLE) and in situ clean-up followed by liquid chromatography with fluorescence and ultraviolet detection. Extraction of 0.5 g sediment samples with 7 mL acetone in the presence of activated silica (0.5 g) and powdered copper (0.2 g) using an ultrasonic probe for 1 min resulted in recoveries of target analytes ≥ 78 %. The analytical method was classified as “acceptable green analysis” by the analytical Eco-Scale assessment (AESA) and scored 0.54 in the AGREEprep greenness assessment for sample preparation. Matrix-matched calibration was used to quantify analytes with a linear range for PAHs 2–1000 ng g–1, for PEs 100–5000 ng g–1 and for APs and APEOs 40–2000 ng g–1 dry weight. The reached limits of quantification (LOQ) for PAHs ranged from 1.1 to 3.1 ng g−1, for PEs from 122 to 124 ng g−1, for APs from 40 to 51 ng g−1 and for APEOs from 36 to 53 ng g−1. The applicability of the method was demonstrated by the analysis of real sediment samples and natural matrix certified reference material.

Establishment of a GC-HRMS-IDMS-based modified QuEChERS approach for rapid, reliable, and simultaneous determination of organochlorine pesticides in soil

Organochlorine pesticides (OCPs), a class of organic pollutants, are highly toxic and persistent in soil and can have harmful effects on humans, organisms, and agricultural environments when bioaccumulated through the food chain. The existing methods for OCP analysis are complex and time consuming; thus, developing a rapid and reliable method for quantifying and monitoring soil-bound OCPs is essential. This study demonstrates the feasibility of replacing the existing official method for OCP analysis with a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method based on GC-HRMS-IDMS. In this modified QuEChERS method, acetonitrile was replaced with ethyl acetate as the extraction solvent. We also assessed the optimal extraction salt (Original, AOAC, and EN) and dispersive solid-phase extraction clean-up sorbent. The limits of detection (LODs) and quantification (LOQs) of the modified QuEChERS method for 24 OCPs ranged from 0.02 to 0.24 ng/g and from 0.06 to 0.3 ng/g, respectively. The recovery rates at the LOQ level were 59.6–115.9 % for the Original method, 60.5–112.5 % for the AOAC method, and 59.6–115.9 % for the EN method. Furthermore, soil samples contaminated with endosulfan were analyzed using the three QuEChERS methods to compare their contents and deviation. EN exhibited more accurate results than Original and AOAC. Thus, the sample processing method using QuECHERS can replace the existing method.

Multiresidue method for the determination of critically and highly important classes of antibiotics and their metabolites in agricultural soils and sewage sludge

In this paper, a method is proposed for the determination of antibiotics classified by the World Health Organization as critically important (four macrolides and three quinolones) and highly important (one tetracycline, one diaminopyridine, and three sulfonamides) and eight of their metabolites. The method is based on ultrasound-assisted extraction, dispersive solid-phase extraction clean-up, and analytical determination by liquid chromatography–tandem mass spectrometry. Variables affecting each stage of the analytical method were thoroughly optimised. The method was validated for its application to sewage sludge from different treatment stages (non-treated sludge: primary and secondary sludge; and treated sludge: digested sludge and compost) and to agricultural soil. Limits of quantification were in the range of 0.03–7.50 ng g−1 dry weight (dw) for most of the compounds. Accuracy values were in the range of 70–102%. Precision was below 17%. The application of the method to real samples revealed that macrolides and fluoroquinolones were the antibiotic classes at the highest concentrations in all types of samples. The lowest concentrations of antibiotics were measured in compost (highest concentration: 27 ng g−1 dw, corresponding to norfloxacin) and soil samples (highest concentration: 93 ng g−1 dw, corresponding to a metabolite of clarithromycin). The proposed method is the first developed to date for the determination of multiclass antibiotics and their main metabolites in sludge from different treatment stages. The method can provide a useful tool for obtaining information about antibiotics in sewage sludge prior to its application to agricultural soils and in agricultural soils.Graphical

Analysis of authorized coccidiostats in chicken feces and environmental water by ultra-performance liquid chromatography-tandem mass spectrometry based on dispersive solid-phase extraction and lyophilization

A simple, sensitive, and efficient method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of 8 coccidiostats in chicken feces and environmental water (including sewage, pond water, and lake water) surrounding the farm. Target analytes in chicken feces were extracted with 2% acetic acid in acetonitrile solution, followed by a dispersive solid-phase extraction (DSPE) cleanup step using the mixture of PSA and C18 adsorbents. Environmental water samples were pretreated using a lyophilization approach. Analysis was carried out on a UPLC-MS/MS with the combination of methanol and 0.1% formic acid aqueous solution as the mobile phase under multiple reaction monitoring in positive and negative ionization modes. Results showed that 8 coccidiostats were linear with correlation coefficients higher than 0.99. Method validation was performed using fortified samples, reaching satisfactory recoveries of 75.9%–97.8% in chicken feces and 71.9%–108.2% in environmental water. Limits of detection for 8 analytes in chicken feces and environmental water were 0.03∼2 µg/kg and 0.005∼1 µg/L, respectively. Matrix effects were calculated and strong signal suppression (>50%) for some coccidiostats was observed. The developed method was successfully applied to analyze coccidiostats in chicken feces and environmental water collected from local chicken farms.

Algerian Workers' Exposure to Mycotoxins-A Biomonitoring Study.

Mycotoxins, produced by fungi as secondary metabolites, have the potential to induce both short-term and long-term toxic consequences in animals and humans. The present study aimed to determine multi-mycotoxin levels in Algerian workers using urine as the target. A method based on a QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction procedure followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was optimized and validated for the determination of eleven mycotoxins in 96 urine samples. Different sorbents were tested to be used in the dispersive solid-phase extraction (d-SPE) cleanup step of QuEChERS. The final method was fit-for-purpose and showed good analytical performance in terms of specificity, linearity, and precision. All samples contained at least two mycotoxins, and toxin-2 (T-2) was the most common, being found in 92.7% of the samples, followed by zearalenone (ZEN) in 90.6% of positive samples, and ochratoxin A (OTA) in 86.4%. T-2 levels ranged from 0.3 μg/L to 36.3 μg/L, while OTA ranged from 0.3 μg/L to 3.5 μg/L, and ZEN ranged from 7.6 μg/L to 126.8 μg/L. This was the first mycotoxin biomonitoring study carried out in the Algerian population. The findings highlight the need for accurate data for better risk assessment and for the development of better regulation to manage mycotoxin contamination in this country.

Highly Efficient and Simultaneous Analysis of Three Common Fluorotelomer Alcohols in Vegetables and Soils.

Fluorotelomer alcohols (FTOHs), as precursors of perfluoroalkyl carboxylic acids, are difficult to analyze due to their high volatility and matrix interference. A method based on single-factor experiments and response surface methodology design was developed for simultaneous analysis of three common FTOHs in vegetables and soils, using single extraction, dispersive solid phase extraction cleanup, and gas chromatography-mass spectrometry in negative chemical ionization. The method improved the extraction efficiency up to ∼40 folds and showed a commendable linearity range (1-100 ng/mL, R2 > 0.991), low limit of detection (0.025-0.897 ng/g, dry weight (dw)), and high accuracy and precision (83 ± 7.2-117 ± 6.0% recoveries at 2-20 ng/g fortification levels). It was successfully applied to determine the FTOHs in real vegetables and soils, demonstrating its feasibility for routine analysis. Concentrations of the FTOHs ranged from 3.5 to 37.9 ng/g (dw) and from 6.5 to 141.0 ng/g (dw), respectively, in the vegetables and soils collected nearby fluorochemical factories, which warrants further investigations on FTOH pollution and food safety concerns for which the developed method will be useful.

Korean Proficiency Tests for Pesticide Residues in Rice: Comparison of Various Proficiency Testing Evaluation Methods and Identification of Critical Factors for Multiresidue Analysis.

Establishing pesticide safety management for agricultural products necessitates accurate pesticide analysis at analytical laboratories. Proficiency testing is regarded an effective method for quality control. Herein, proficiency tests were carried out for residual pesticide analysis in laboratories. All samples satisfied the homogeneity and stability criteria of the ISO 13528 standard. The obtained results were analyzed using the ISO 17043 z-score evaluation. Both individual pesticide and multiresidue proficiency evaluations were performed, and the proportion of z-scores within the ±2 range ("Satisfactory" rating) obtained for seven pesticides ranged 79-97%. Of the laboratories, 83% were classified as Category A using the category A/B method, and these also received AAA ratings in the triple-A evaluations. Furthermore, 66-74% of the laboratories were rated "Good" via five evaluation methods based on their z-scores. The sum of weighted z-scores and scaled sum of squared z-scores were considered as the most suitable evaluation techniques, as they compensated for the drawbacks of good results and corrected the poor results. To identify the main factors affecting laboratory analysis, the experience of the analyst, sample weight, calibration curve preparation method, and cleanup status were considered. A dispersive solid phase extraction cleanup significantly improved the results (p < 0.01).

Analysis of Organochlorine Pesticides in a Soil Sample by a Modified QuEChERS Approach Using Ammonium Formate

Currently, the QuEChERS method represents the most widely used sample preparation protocol worldwide for analyzing pesticide residues in a broad variety of matrices both in official and non-official laboratories. The QuEChERS method using ammonium formate has previously proven to be advantageous compared to the original and the two official versions. On the one hand, the simple addition of 0.5 g of ammonium formate per gram of sample is sufficient to induce phase separation and achieve good analytical performance. On the other hand, ammonium formate reduces the need for maintenance in routine analyses. Here, a modified QuEChERS method using ammonium formate was applied for the simultaneous analysis of organochlorine pesticide (OCP) residues in agricultural soil. Specifically, 10 g of the sample was hydrated with 10 mL of water and then extracted with 10 mL of acetonitrile. Next, phase separation was carried out using 5 g of ammonium formate. After centrifugation, the supernatant was subjected to a dispersive solid-phase extraction clean-up step with anhydrous magnesium sulfate, primary-secondary amine, and octadecylsilane. Gas chromatography-mass spectrometry was used as the analytical technique. The QuEChERS method using ammonium formate is demonstrated as a successful alternative for extracting OCP residues from a soil sample.

Development of two fully automated quick, easy, cheap, effective, rugged, and safe pretreatment methods for the extraction of psychotropic drugs from whole blood samples.

Quick, easy, cheap, effective, rugged, and safe extraction strategies are becoming increasingly adopted in various analytical fields to determine drugs in biological specimens. In the present study, we developed two fully automated quick, easy, cheap, effective, rugged, and safe extraction methods based on acetonitrile salting-out assisted liquid-liquid extraction (method 1) and acetonitrile salting-out assisted liquid-liquid extraction followed by dispersive solid-phase extraction (method 2) using a commercially available automated liquid-liquid extraction system. We applied these methods to the extraction of 14 psychotropic drugs (11 benzodiazepines and carbamazepine, quetiapine, and zolpidem) from whole blood samples. Both methods prior to liquid chromatography-tandem mass spectrometry analysis exhibited high linearity of calibration curves (correlation coefficients,>0.9997), ppt level detection sensitivities, and satisfactory precisions (< 8.6% relative standard deviation), accuracies (within±16% relative error), and matrix effects (81-111%). Method 1 provided higher recovery rates (80-91%) than method 2 (72-86%), whereas method 2 provided higher detection sensitivities (limits of detection, 0.003-0.094ng/mL) than method 1 (0.025-0.47ng/mL) owing to the effectiveness of its dispersive solid-phase extraction cleanup step. These fully automated extraction methods realize reliable, labor-saving, user-friendly, and hygienic extraction of target analytes from whole blood samples.

Comparison of conventional and dispersive solid phase extraction clean-up approaches for the simultaneous analysis of tetracyclines and sulfonamides in a variety of fresh vegetables

The extensive use of antibiotics in agriculture has led to the occurrence of residual drugs in different vegetables frequently consumed by humans. This could pose a potential threat to human health, not only because of the possible effects after ingestion but also because the transmission of antibiotic-resistant genes could occur. In this work, two accurate sample preparation procedures were developed and validated for the simultaneous analysis of sulfonamides (SAs) and tetracyclines (TCs) in four of the most widely consumed vegetables (lettuce, onion, tomato, and carrot) in Europe. The evaluated protocols were based on QuECHERS for extraction and subsequent clean-up by SPE (solid phase extraction) or dispersive SPE. Parameters affecting both extraction and clean-up were carefully evaluated and selected for accuracy of results and minimal matrix effect. Overall, apparent recoveries were above 70% for most of the target analytes with both analytical procedures, and adequate precision (RSD<30%) was obtained for all the matrices. The procedural limits of quantification (LOQPRO) values for SPE clean-up remained below 4.4 μg kg−1 for TCs in all vegetables except for chlortetracycline (CTC) in lettuce (11.3 μg kg−1) and 3.0 μg kg−1 for SAs, with the exception of sulfadiazine (SDZ) in onion (3.9 μg kg−1) and sulfathiazole (STZ) in carrot (5.0 μg kg−1). Lower LOQPRO values (0.1–3.7 μg kg−1) were obtained, in general, when dSPE clean-up was employed. Both methods were applied to twenty-five market vegetable samples from ecological and conventional agriculture and only sulfamethazine (SMZ) and sulfapyridine (SPD) were detected in lettuce at 1.2 μg kg−1 and 0.5 μg kg−1, respectively.

Determination of methanol-derivatives in drying oils after metal oxide-based dispersive solid phase extraction/QuEChERS clean-up

The determination of secondary volatile degradation products in drying oil extracts is substantial to prevent formation of undesirable metal formates in paintings and/or other artefacts. This study develops a simple, cost-effective, and reliable, high-performance liquid chromatography with diode array detector (HPLC–DAD) method to determine three secondary volatile degradation products (methanol, formaldehyde, and formic acid) in drying oils, including linseed, poppy-seed, and walnut oil. Extraction of analytes was performed using QuEChERS-based procedure followed by metal oxide-based dispersive solid-phase extraction (d-SPE) clean-up and presented a good performance for all of the volatile analytes of interest with recoveries in the range of 90–120% after application of the nanostructured cerium oxide-based (CeO2) and zirconia-based (ZrO2) sorbents prepared by favorable and ecological-friendly methods. With a new clean-up solution for samples with high-fat content, it was possible to achieve higher recoveries than with commercial Z-Sep/C18 sorbent. In all cases, relative standard deviations (RSD) of less than 10% were achieved. No significant matrix interference was observed due to the application of effective sorbents in nanostructured form. The developed method was applied to samples of drying oils, and it was found that after storage for three months, all methanol was most likely oxidized to formaldehyde and formic acid. The concentrations of formaldehyde were in the range of 260 - 304 μg∙g−1, while formic acid concentrations ranged between 72 - 386 μg∙g−1. The highest concentration of formaldehyde (304 μg∙g−1) and formic acid (386 μg∙g−1) was found in linseed oil.

Determination of pharmaceuticals and metabolites in sludge and hydrochar after hydrothermal carbonization using sonication-QuEChERS extraction method and UHPLC LTQ/Orbitrap MS.

Pharmaceuticals (PhACs) are an important group of emerging contaminants that are released continuously in the environment from wastewater treatments plants (WWTPs). They can produce biological effects even though at very low concentrations. Conventional WWTPs are not able to remove or degrade completely emerging pollutants resulting in the presence of PhACs in sewage sludge after wastewater treatment. PhACs are found in sludge at low ppb-ppt levels, and their analysis and detection is a difficult task due to the complexity of sewage sludge matrices. Hydrothermal carbonization is currently being proposed as a suitable conversion technology for sewage sludge management to recover valuable products and to be used for soil amendment. In this work, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methodology with a dispersive solid-phase extraction (d-SPE) clean-up followed by ultra-high-performance liquid chromatography coupled with high-resolution linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ/Orbitrap MS), operated in positive ionization mode, was adopted to investigate 33 multiclass pharmaceuticals in sewage sludge and in hydrochar produced after hydrothermal carbonization. The analytical method was first optimized studying various extraction parameters and finally validated in terms of linearity, recovery, intra and inter-day precisions, expanded uncertainty (%U)/Horrat ratio at three spiking levels, matrix-effects (ME), process efficiency (PE), and limits of detection and quantification. The developed methodology fulfilled all analytical requirements and was finally applied to sludge samples from the WWTP of Ioannina city where a group of antibiotics was detected at concentrations up to 15ngg-1 and psychiatric drugs such as amisulpride, clozapine, and citalopram were detected at higher concentration levels up to 205, 87.4 and 63.2ngg-1, respectively. The method was also applied to hydrothermally treated sludge sample under different reaction conditions. Most of the antibiotic compounds were not detected, and several psychiatric drugs such as mirtazapine, bupropion, valsartan, diazepam, and caffeine were found at concentrations below the LOQ.

Method development and optimisation for analysis of pesticide residues in biological matrices by modified QuEChERS and gas chromatography–triple quadrupole mass spectrometry

ABSTRACT A rapid and precise modified QuEChERS method for extraction was developed for simultaneous quantitation of multi-class pesticide residues in human biological matrices, viz. blood, serum and urine. In the modified QuEChERS method, targeted analytes in biological sample were extracted using acidified solution of acetonitrile and ethyl acetate along with anhydrous MgSO4. The collected aqueous layer was evaporated and dispersive solid-phase extraction clean-up was performed. The pesticide residues were assessed using gas chromatography–tandem mass spectrometry with multiple reaction monitoring mode. The developed method was validated as per European Union SANTE/12682/2019 guidelines and the evaluated method validation parameters, viz. linearity, limit of detection, limit of quantitation, accuracy, %relative standard deviation and matrix effect were found to be satisfactory. The proposed method is easy, comprehensible and efficient for simultaneous analysis of diverse range of pesticide residues within similar class. Hence, the present solitary method can be used for systematic analysis of biological samples.

Simultaneous focused ultrasound solid–liquid extraction and dispersive solid-phase extraction clean-up for gas chromatography–tandem mass spectrometry determination of polycyclic aromatic hydrocarbons in crustacean gammarids meeting the requirements of the European Union Water Framework Directive

The study presents the development and validation of a method for the determination of seven priority polycyclic aromatic hydrocarbons (PAHs, including fluoranthene and benzo[a]pyrene, for which the EU has set environmental quality standards, EQS, for biota) in gammarid samples combining focused ultrasound solid–liquid extraction and dispersive solid-phase extraction clean-up in one step followed by gas chromatography–triple quadrupole tandem mass spectrometry (GC–QqQ-MS/MS). The method is designed to analyse small about 100 mg dry weight (dw) samples obtained after lyophilisation of 500 mg wet weight (ww) samples. The sample preparation procedure is simple, environment friendly (method was classified as “an excellent green analysis” according to the analytical Eco-Scale assessment), non-laborious and low-cost and, apart from the sample extract concentration step, is quick. Thorough disintegration of the gammarids is achieved by a combination of sonication and the addition of granular anhydrous Na2SO4 to the gammarid suspension, thus avoiding the need to grind the sample prior to analysis. The QqQ-MS/MS detector, thanks to its excellent selectivity and sensitivity, allows to meet the EQS requirements for PAHs in biota with a good margin (limits of quantification in the range of 0.12 and 0.56 ng g‒1 ww). The method has been successfully validated (in terms of linearity, method limits, precision, trueness, robustness, measurement uncertainty and comparative analysis of real samples), and has been shown to be suitable for monitoring and evaluating the PAHs contamination in surface water biota.

Targeted and non-targeted analysis of pesticides and aflatoxins in baby foods by liquid chromatography coupled to quadrupole Orbitrap mass spectrometry

In this study, 21 pesticides and 4 aflatoxins were monitored in baby food marketed in Brazil, applying ultra-high-performance liquid chromatography coupled to quadrupole-Orbitrap mass spectrometry (UHPLC-Q-Orbitrap-MS). The quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method combined with dispersive solid-phase extraction (d-SPE) clean-up was applied and primary secondary amine (PSA), octadecylsilane (C18) and C18 with silica coated with zirconium dioxide (Z-Sep+) were used during the clean-up stage. Suitable performance criteria, set by the SANTE/2020/12830 guidelines, were achieved, and therefore, all targeted analytes were successfully validated. The method was applied to the analysis of 50 baby food samples. Cypermethrin was detected at 10.3 μg kg−1 (above maximum residue level (MRL) established by the European Union (EU)). Furthermore, suspect screening analysis was performed for reliable identification of contaminants not included in this study such as other pesticides, mycotoxins, hormones, veterinary drugs and their metabolites. Finally 10 pesticides and one metabolite were detected, demonstrating the suitability of the proposed approach.

Occurrence of polycyclic aromatic compounds in guarana (Paullinia cupana) seeds subjected to different drying processes

In this study, the levels of polycyclic aromatic compounds (PACs), such as polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (oxy-PAHs) were investigated in guarana seeds (Paullinia cupana) subjected to different drying methodologies. An innovative extraction method combined with a miniaturized dispersive solid-phase extraction cleanup procedure was developed for the determination of PACs concentration. Thirteen-eight guarana seed samples subjected to three different drying methodologies (sun drying, greenhouse drying, and alguidar furnace drying) were collected from different rural producers in the South Region of the State of Bahia, Brazil. Principal component analysis and diagnostic ratios were used to evaluate the correlation between samples and the PACs and the main sources of contamination. According to the results, the average concentration of PACs found in sun-dried, greenhouse-dried, and alguidar-dried ranged from 1.30 µg kg−1 (coronene) to 114 µg kg−1 (fluorene), from 0.48 µg kg−1 (dibenzo[a,h]anthracene) to 128 µg kg−1 (fluorene), and from 6.0 µg kg−1 (anthracene) to 422 µg kg−1 (phenanthrene). Oxy-PAHs, such as 1,4-NQ was detected predominantly in sun-dried and greenhouse-dried samples at concentrations ranging from 30.7 µg kg−1 to 83.9 µg kg−1. Low molecular weight PAHs, such as naphthalene, acenaphthylene, and fluorene were found in most of the samples independently of drying methodology. However, high molecular weight PAHs, including the carcinogenic benzo[a]pyrene was found predominately in alguidar-dried samples in concentrations higher than 20 µg kg−1.

Development and validation of a highly effective analytical method for the evaluation of the exposure of migratory birds to antibiotics and their metabolites by faeces analysis

The widespread occurrence of antibiotics in the environment may exert a negative impact on wild organisms. In addition, they can become environmental reservoirs, through the ingestion of food or contaminated water, and vectors for antibiotic-resistant bacteria. This fact is even more important in migratory birds that can promote their dissemination across continents. In this work, a multiresidue analytical method suitable for the determination of five families of antibiotics and their main metabolites in waterbird faeces has been developed and validated. The target compounds include environmentally significant sulfonamides, macrolides, fluoroquinolones, tetracyclines and antifolates. Sample treatment involves ultrasound-assisted extraction with methanol and dispersive solid-phase extraction clean-up with C18. Analytical determination was carried out by liquid chromatography–tandem mass spectrometry. The most significant parameters affecting sample extraction and extract clean-up were optimised by means of experimental designs. Good linearity (R2 > 0.994), accuracy (from 41 to 127%), precision (relative standard deviation lower than 24%) and limits of quantification (lower than 2 ng g−1 (dry weight, dw)) were obtained for most of the compounds. The method was applied to the determination of the selected compounds in 27 faeces samples from three common migratory waterbird species. Nine antibiotics and three of their metabolites were detected in the analysed samples. Fluoroquinolones and macrolides were the antibiotics most frequently detected. The highest concentrations corresponded to norfloxacin (up to 199 ng g−1 dw).Graphical abstract

Simultaneous Focused Ultrasound Solid–Liquid Extraction and Dispersive Solid Phase Extraction Clean-Up for Gas Chromatography–Tandem Mass Spectrometry Determination of Polycyclic Aromatic Hydrocarbons in Crustacean Gammarids Meeting the Requirements of the EU Water Framework Directive

Simultaneous Focused Ultrasound Solid–Liquid Extraction and Dispersive Solid Phase Extraction Clean-Up for Gas Chromatography–Tandem Mass Spectrometry Determination of Polycyclic Aromatic Hydrocarbons in Crustacean Gammarids Meeting the Requirements of the EU Water Framework Directive

Development of a USE/d-SPE and targeted DIA-Orbitrap-MS acquisition methodology for the analysis of wastewater-derived organic pollutants in fish tissues and body fluids

Pharmaceuticals (PhACs) are partially removed during wastewater treatment and end up in the receiving waters. As a result, aquatic biota is continuously exposed to a wide range of potentially hazardous contaminants such as PhACs. Therefore, fish could be a good bio indicator to give a direct measure of the occurrence of PhACs in the aquatic environment. In this study, a robust analytical method has been optimized and validated for the determination of 81 organic compounds, mainly PhACs, in seven wild fish tissue types (liver, muscle, pancreas, kidney, skin, heart, and brain) and two body fluids (plasma and bile). Solid samples extraction was performed combining a procedure based on bead beating tissue homogenization plus ultrasound extraction followed by dispersive solid-phase extraction (dSPE) clean-up using zirconia and C18 sorbents for solid matrices, whereas bile and plasma were diluted.The key aspects of this method are:• The method facilitated the simultaneous extraction of 81 PhACs of a wide range of polarity (logP from -4.9 to 5.6) in tissues with variable lipid content.• The validation was performed using Cyprinus carpio at 20 ng g−1 and 200 ng g−1 for solid tissues, 50 ng mL−1 and 500 ng mL−1 for plasma, and 100 ng mL−1 and 1000 ng mL−1 for bile. Analyte detection was performed in LC-HRMS Q-Exactive Orbitrap system with full scan and targeted data-independent acquisition (DIA) mode for high-confidence and sensitive quantitation in either (+) or (-) ESI mode.• The majority of compounds presented recoveries between 40% and 70% and relative standard deviations (RSD) below 30%.