Extraction Clean-up Research Articles

Simultaneous determination of macrolide and quinolone antibiotics in animal tissues for human consumption validated by Regulation (EU) 2021/808

In this work, an analytical method for the simultaneous detection and quantification of 11 macrolides (erythromycin A, gamithromycin, lincomycin, neospiramycin, pirlimycin, spiramycin, tildipirosin, tilmicosin, tulathromycin A and its metabolite CP-60300, and tylosin A) and 10 quinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, nalidixic acid, norfloxacin, oxolinic acid, and sarafloxacin) in muscle (bovine, ovine, porcine, equine, rabbit, poultry including laying hens, and fish) and kidney (bovine, ovine, porcine, equine) for human consumption was developed and validated according to Commission Implementing Regulation (EU) 2021/808. Sample preparation consisted of liquid extraction using a citrate–phosphate/EDTA buffer solution (McIlvaine buffer) followed by solid phase extraction for cleanup and UHPLC-MS/MS analysis. The developed method was comprehensively validated with regard to relative matrix effects (CVMF ≤ 20 %), linearity (R2 ≥ 0.98), accuracy (84–119 %), trueness (−16 to + 19 %), repeatability (2.1–20.0 %), reproducibility (3.0–25.0 %), selectivity, and robustness. The method limit of quantification values ranged from 2 to 40 µg kg−1, established as 0.1 × the lowest maximum residue limit (MRL) by species for the authorized antibiotics. Method applicability was demonstrated in six interlaboratory proficiency tests, and in the official control analyses of 1200 field samples of muscle and kidney.

Systematic Comparison of Extract Clean-Up with Currently Used Sorbents for Dispersive Solid-Phase Extraction

Dispersive solid-phase extraction (dSPE) is a crucial step for multiresidue analysis used to remove matrix components from extracts. This purification prevents contamination of instrumental equipment and improves method selectivity, sensitivity, and reproducibility. Therefore, a clean-up step is recommended, but an over-purified extract can lead to analyte loss due to adsorption to the sorbent. This study provides a systematic comparison of the advantages and disadvantages of the well-established dSPE sorbents PSA, GCB, and C18 and the novel dSPE sorbents chitin, chitosan, multi-walled carbon nanotube (MWCNT), and Z-Sep® (zirconium-based sorbent). They were tested regarding their clean-up capacity by visual inspection, UV, and GC-MS measurements. The recovery rates of 98 analytes, including pesticides, active pharmaceutical ingredients, and emerging environmental pollutants with a broad range of physicochemical properties, were determined by GC-MS/MS. Experiments were performed with five different matrices, commonly used in food analysis (spinach, orange, avocado, salmon, and bovine liver). Overall, Z-Sep® was the best sorbent regarding clean-up capacity, reducing matrix components to the greatest extent with a median of 50% in UV and GC-MS measurements, while MWCNTs had the largest impact on analyte recovery, with 14 analytes showing recoveries below 70%. PSA showed the best performance overall.

Valorization of Date Fruit (Phoenix dactylifera L.) as a Potential Functional Food and Ingredient: Characterization of Fiber, Oligosaccharides, and Antioxidant Polyphenols.

The fruit of the date tree (Phoenix dactylifera L.) is increasingly recognized for its nutritional and functional value. This exotic fruit shows variable composition, influenced by factors such as variety, ripening stage, and climatic conditions. In this context, this study aimed to investigate the nutritional profile and the bioactive components, including phenolic compounds and oligosaccharides, in different varieties of dates from Saudi Arabia collected at the Tamr ripening stage. The HPLC-ESI-MS analysis identified a total of 15 phenolic compounds, principally phenolic acids and flavonoids. Among the varieties tested, Safawi exhibited the highest phenolic concentration (1132 µg/100 g dw). To the best of our knowledge, the oligosaccharide composition is described for the first time among different varieties, with Sukari showing the highest concentration (3.37 g/100 g dw). Moreover, the antioxidant capacity (DPPH, ABTS, and FRAP assays) was assessed following a solid-phase extraction (SPE) clean-up to remove interferents, especially sugars. These results provide valuable insights into the health-promoting properties of date fruit as a functional food and provide a foundation for further research into their industrial applications as functional ingredients.

Rapid green analytical methodology for simultaneous monitoring of nitrosamines and semi-volatile organic compounds in water and human urine samples.

Nitrosamines and semi-volatile organic compounds (SVOCs) are carcinogenic contaminants in water and biological matrices. Conventional analytical methods often struggle to detect trace concentrations due to poor extraction efficacies. This study presents a novel, low-cost, in-syringe-assisted fast extraction cum cleanup technique coupled with GC-FID for monitoring four nitrosamines and two SVOCs in drinking water and human urine samples to measure the contamination and exposure levels. This extraction protocol combines a novel green in-syringe liquid-liquid extraction step using dimethyl carbonate as the green extraction solvent, coupled with a semi-automated solid-phase extraction cleanup process. Then, the final extractant is analyzed using gas chromatography-flame ionization detection (GC-FID) for monitoring. The method demonstrated excellent linearity (R2 > 0.998) between 1.5 and 500ngmL⁻1 for all six target compounds. Detection limits ranged from 1.0 to 2.0ngmL⁻1. Extraction recoveries were between 87 and 105% for both urine samples and water samples. Intra-day and inter-day precision were below 9% RSD. The blue applicability grade index evaluation scored 70.0, indicating good practical applicability. The developed analytical protocol offers a sensitive, accurate, low-cost, rapid, and environmentally friendly method for simultaneously quantifying multiple nitrosamines and SVOCs in environmental and human samples. Its performance characteristics and sustainability metrics suggest the potential for broad application in monitoring and exposure studies.

Optimization and Validation of a Cheaper, Safer, and More Sustainable Methodology for Aflatoxins Determination in Rich-Lipidic Matrices (Pistachio Nuts) Using Deep Eutectic Solvent Extraction and UHPLC-FLD Analysis.

Aflatoxins pose a major health concern and require strict monitoring in food products. Existing methods rely on hazardous organic solvents for extraction, prompting the development of a greener alternative. This study explores deep eutectic solvents (DESs) for aflatoxin extraction from pistachios, a valuable food product prone to aflatoxin contamination. The proposed method utilizes DES extraction followed by solid-phase extraction cleanup and ultrahigh-performance liquid chromatography coupled with fluorescence detector analysis. Recovery rates ranged from 85.5 to 99.1% for pistachios spiked with 1-8 ng/g aflatoxins, in compliance with EU regulations, with coefficients of variation less than 2.94%. The method demonstrates good sensitivity with limits of detection and quantification in the range of 0.02-0.22 ng/g and 0.05-0.72 ng/g, respectively. Greenness assessment using AGREEPrep and White Analytical Chemistry metrics confirms its environmental sustainability. This approach offers a promising, safer, and more eco-friendly alternative for aflatoxin extraction from complex food matrices like pistachios.

Determination of tetrodotoxin in human plasma and urine using online MCX SPE column cleanup coupled with liquid chromatography-tandem mass spectrometry

An efficient technique for quantitative analysis of tetrodotoxin (TTX) in human plasma and urine has been developed, which combines liquid chromatography-tandem mass spectrometry (LC-MS/MS) with online MCX solid phase extraction (SPE) cleanup. Sample preparation, including extraction with acetonitrile containing 0.5 % acetate acid, centrifugation, and filtration, was followed by online SPE cleanup. The whole run-time was less than 15 min, including online cleanup, chromatographic separation, and re-equilibration of the online SPE − LC-MS/MS system. The parameters of sample extraction, purification, separation, and detection were optimized. The matrix-matched internal standard calibration standard curves with linear regression coefficients larger than 0.9990 were established for quantification. The LOD and LOQ for this approach were determined to be 0.1 ng/mL and 0.3 ng/mL, respectively. The recoveries for varied concentrations of TTX in human plasma and urine were 84.9–104.2 % and 89.2–109.6 %, respectively. The matrix effects of TTX in human plasma and urine matrices were 85.5 % and 74.3 %, respectively, and both the inter- and intra-day precision values were less than 9.5 %. This analytical method was successfully employed for detecting TTX in biological samples from a poisoned patient who accidentally ingested the nassarius glans.

High-Performance Liquid Chromatographic Quantification of the Plant Hormone Abscisic Acid at ppb Levels in Plant Samples after a Single Immunoaffinity Column Cleanup.

High-performance liquid chromatography with ultraviolet detection (HPLC-UV) is a common analysis technique due to its high versatility and simple operation. In the present study, HPLC-UV detection was integrated with immunoaffinity cleanup (IAC) of the sample extracts. The matrix effect was greatly reduced, and the limit of detection was as low as 1 ng/g of free abscisic acid (ABA) in fresh plant tissues. A monoclonal antibody 3F1 (mAb 3F1) was developed to specifically recognize free ABA but not ABA analogues. The mAb 3F1-immobilized immunoaffinity column exhibited a capacity of 850 ng/mL and an elution efficiency of 88.8-105% for standards. The extraction recoveries of the column for ABA ranged from 80.4 to 108.9%. ABA content was detected in various plant samples with IAC-HPLC-UV. The results were verified with ultraperformance liquid chromatography-electrospray tandem mass spectrometry. IAC-HPLC-UV can be a sensitive and cost-efficient method for plant hormone analysis.

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.

Accurate Quantification of Okadaic Acid Group Toxins in Bivalves by Simple Solid-Phase Extraction Clean-up Using Hydrophilic-Lipophilic Packing Materials

Accurate Quantification of Okadaic Acid Group Toxins in Bivalves by Simple Solid-Phase Extraction Clean-up Using Hydrophilic-Lipophilic Packing Materials

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.

Quantification of parabens in marine fish samples by a rapid, simple, effective sample preparation method.

Parabens (p-hydroxybenzoic acid esters) commonly used preservatives (in cosmetics, pharmaceuticals, and foods) can pose potential effects on environmental health. In this study, seven parabens were quantified in marine fish samples using an ultra-high performance liquid chromatography triple quadrupole mass spectrometer (UHPLC-MS/MS) system. Parabens in the fish samples were extracted and purified by a rapid, simple, and effective procedure comprising sample homogenization with solvent, solid-phase extraction clean-up, and solvent evaporation. Results demonstrated that the recoveries of seven compounds (with relative standard deviation < 15%) were 88-103% in matrix-spike samples and 86-105% in surrogate standards. The method detection limits and method quantification limits of seven parabens were 0.015-0.030 and 0.045-0.090ng/g-ww (wet weight), respectively. The optimized method was applied to measure the concentration of parabens in the 37 marine fish samples collected from Vietnam coastal waters. The concentration ranges of seven parabens found in round scad and greater lizardfish samples were 6.82-25.3ng/g ww and 6.21-17.2ng/g-ww, respectively. Among parabens, methylparaben accounted for the highest contribution in both fish species (43.2 and 44.9%, respectively). Based on the measured concentrations of parabens in marine fish samples, the estimated daily intake was calculated for children and adults with the corresponding values of 0.0477µg/kg/day and 0.0119µg/kg/day, respectively. However, the presence of parabens in Vietnamese marine fish may not pose a significant risk to human health.

Assessing Matrix Solid-Phase Dispersion Extraction Strategies for Determining Bisphenols and Phthalates in Gilthead Sea Bream Samples

Microplastics (MPs) and nanoplastics (NPs) are widely spread in the environment, generating significant concern due to their potential impact on environmental health. Marine species usually ingest plastic fragments, mistaking them for food. Many toxic compounds, such as plastic additives that are not chemically bound to the plastic matrix, can be released from MPs and NPs and reach humans via the food chain. This paper highlights the development and validation of a straightforward solid–liquid extraction clean-up procedure in combination with a matrix solid-phase dispersion method using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) detection, enabling facile, precise, and reliable identification and quantitation of a total of six bisphenols and phthalates in gilthead sea breams. Under the optimized conditions, the developed method showed good linearity (R2 &gt; 0.993) for all target compounds. The recoveries obtained were between 70 and 92%. The relative standard deviations (RSDs) for reproducibility (inter-day) and repeatability (intra-day) were less than 9% and 10%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the target compounds ranged from 0.11 to 0.68 µg/kg and from 0.37 to 2.28 µg/kg, respectively. A new, efficient extraction methodology for the determination of BPA, BPS, BPF, DBP, DEP, and DHEP in gilthead seabream has been optimized and validated.

Screening stabilisers for cyanoenone triterpenoid TX101 in rat plasma samples by simultaneous analysis of parent drug and the epoxidation product.

In the development of bioanalytical methods, stabilizing drug molecules in biological matrices is crucial for ensuring reliable exposure data in pharmacokinetic and toxicokinetic sample analyses. This study focuses on the evaluation of stabilizing effects on the synthetic triterpenoid TX101, a cyanoenone triterpenoid Nrf2 activator with known instability in plasma samples. The molecule's unsaturated double bond is susceptible to oxidation, either nonenzymatically via oxygen or enzymatically through cytochrome P450 enzyme-catalyzed epoxidation. The research explores the impact of antioxidants (L-ascorbic acid, sodium metabisulfite, sodium sulfite) and P450 enzyme inhibitors (sodium diethyldithiocarbamate, memantine hydrochloride, 1-aminobenzotriazole) on TX101 stability in rat plasma samples. Results reveal that adding 2.5 mg/mL sodium sulfite or sodium metabisulfite effectively inhibits the nonenzymatic oxidation of TX101 to TX101-epoxide, while L-ascorbic acid shows minimal stabilizing effect. Among P450 enzyme inhibitors, sodium diethyldithiocarbamate and memantine hydrochloride exhibit modest stabilizing effects, likely attributed to their antioxidant activity. The developed High-formance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method, incorporating Supported Liquid Extraction for sample cleanup, allows simultaneous monitoring of TX101 and TX101-epoxide. Application of this method in a rat dose-range finding study confirms successful inhibition of TX101-epoxide formation in samples treated with sodium sulfite or sodium metabisulfite. Overall, the study emphasizes the importance of stabilizers in preventing nonenzymatic oxidation reactions during sample storage, providing valuable insights for bioanalytical method development and validation.

Rapid analysis and risk assessment of perchlorate in wild edible mushrooms from Yunnan, China

Ubiquitous perchlorate contamination has become an important food safety issue related to human health, but contamination characteristics and health risks of perchlorate in wild edible mushrooms remain unclear. In this study, a method based on dispersive solid phase extraction (d-SPE) clean-up procedure combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established for the rapid analysis of perchlorate in wild edible mushrooms. Sample pretreatment was achieved by acetonitrile extraction followed by clean-up with florisil and graphitized carbon black (GCB). The proposed method presented satisfactory linearity, accuracy, precision, negligible matrix effects, and low limit of detection (LOD) (0.15 µg/kg) and limit of quantification (LOQ) (0.5 µg/kg). The recoveries at four levels (0.5, 3, 30 and 300 µg/kg) were 93.1–108.7% with relative standard deviation ranging from 2.9% to 18.2% for mushroom samples. The validated methodology was successfully applied to detect 109 wild edible mushroom samples belonging to 8 species collected from Yunnan, China, and 95.41% of the samples were found to have detectable perchlorate contamination. Concentrations of perchlorate ranged from below LOD to 29.81 μg/kg, with a mean value of 4.11 μg/kg. The risk assessment results for perchlorate in wild edible mushrooms showed no health risks to consumers.

Residues of Deltamethrin in Pine Needles and Pine Nuts of Catalonia (Spain).

In recent years, recurrent droughts have weakened stone pine (Pinus pinea) forests and facilitated the emergence of harmful pests and diseases, including the Leptoglossus occidentalis. The production of stone pine nuts has declined over the past five years. To control this hemipteran pest, a synthetic pyrethroid insecticide called deltamethrin is being tested. However, it is necessary to estimate the residue left by these treatments in forest stands. Therefore, a fast and robust analytical procedure was developed based on QuEChERS clean-up extraction, followed by gas chromatography coupled with an electron capture detector. This optimized method can detect residual concentrations of deltamethrin in pine nuts and pine needles up to 0.1 and 6 μg kg-1, respectively, with a limit of quantification of 0.4 and 20 μg kg-1. Great recoveries (between 84 and 102%) were obtained for both matrices, and no matrix effect was observed. The results showed that two weeks after spraying, the deltamethrin content in the needles of stone pines decreased by up to 75%, and after nine months, its presence was like that of nontreated trees.

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.

Simultaneous Determination of Amphenicols in Animal-Derived Foods by Solvent and Solid Phase Extraction With Ultrahigh-Performance Liquid Chromatography Tandem Mass Spectrometry.

The consumption of foods containing amphenicols, a type of antibiotic, is a major concern for human health. A stable and accurate detection method can provide technical support for food-safety monitoring. An effective and efficient method was established for determining amphenicols in animal-derived foods through the simultaneous use of solid-phase extraction (SPE) cleanup and ultrahigh-performance liquid chromatography/mass spectrometry (UPLC-MS/MS). Samples were extracted using 1.0% ammoniated ethyl acetate solution, degreased with n-hexane, and then concentrated and cleaned using a C18 SPE column. Next, gradient elution was performed using methanol and 0.05% aqueous ammonia as the mobile phase, followed by separation using a C18 column. The target compound was detected using electrospray ionization, both in positive and negative modes, through multiple reaction monitoring, and quantified using an internal-standard method. The content of chloramphenicol (CAP), florfenicol (FF), and florfenicol amine (FFA) (content range: 0.2-8.0 µg/kg) as well as that of thiamphenicol (TAP; content range: 1.0-40.0 µg/kg) show a good linear relationship, with a correlation coefficient of r > 0.999. Furthermore, recoveries of 86.7-111.9% and relative standard deviations of <9.0% were achieved. The limits of detection and quantification are obtained as 0.03-0.33 and 0.1-1.0 μg/kg, respectively. The proposed method has excellent stability and accuracy, and can be successfully used for the qualitative and quantitative determination of amphenicols, i.e., CAP, TAP, FF, and FFA residues in 210 animal-derived food samples, of which FF and FFA were detected in four samples. A stable and accurate method was successfully established for the simultaneous determination of CAP, TAP, FF, and FFA in animal-derived foods using UPLC-MS/MS. Effective sample pretreatment was established, lipids were removed using n-hexane, concentration and cleanup were achieved with the C18 SPE column, and matrix effects were effectively reduced, thus improving the method's accuracy and stability. The method was validated for eight common animal-source foods, including beef, lamb, pork, chicken, egg, milk, fish, and honey. This method has good applicability for CAP, TAP, FF, and FFA in animal-derived foods.

Automated micro-solid-phase extraction clean-up and gas chromatography-tandem mass spectrometry analysis of pesticides in foods extracted with ethyl acetate

Generic extraction methods for the multi-compound pesticide analysis of food have found their solid place in laboratories. Ethyl acetate and acetonitrile extraction methods have been developed as fast and easy to handle standard multi-compound methods, both feature benefits and limitations. The direct injection to gas chromatography can be impaired by a high burden of coextracted matrix, resulting in deterioration of the chromatographic system and matrix effects, requiring frequent maintenance. Therefore, common clean-up methods, such as dispersive solid-phase extraction, freeze-out of fats, or gel permeation chromatography, have been applied in clean-up. Automated clean-up using micro-solid-phase extraction (µSPE) is a recent development with several demonstrated advantages when employed in the analysis of pesticides and other contaminants in foods extracted with acetonitrile, but it has not yet been evaluated in this application using ethyl acetate for extraction. In this study, an automated procedure using µSPE cartridges was developed and established on an x,y,z robotic sampler for the raw extract clean-up and preparation of diluted samples for injection on a GC-MS/MS system. Validation experiments for 212 pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons in lettuce, avocado, raspberry, paprika, egg, and liver extracts were performed using µSPE with MgSO4, PSA, C18, and CarbonX. The performance in routine operation is briefly discussed.Graphical abstract

Determination of Domoic Acid in Seafood Matrices using HPLC-UV with Solid Phase Extraction Cleanup

Determination of Domoic Acid in Seafood Matrices using HPLC-UV with Solid Phase Extraction Cleanup

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