Antibiotic residue contamination in the aquatic environment, sources and associated potential health risks.

Antibiotic residues are widely recognized as major pollutants in the aquatic environment on a global scale. As a significant class of pharmaceutically active compounds (PhACs), antibiotics are extensively consumed worldwide. The primary sources of these residues include hospitals, municipal sewage, household disposal, and manures from animal husbandry. These residues are frequently detected in surface and drinking waters, sewage effluents, soils, sediments, and various plant species in countries such as China, Japan, South Korea, Europe, the USA, Canada, and India. Antibiotics are used medicinally in both humans and animals, with a substantial portion excreted into the environment as metabolites in feces and urine. With the advancement of sensitive and quantitative analytical techniques, antibiotics are consistently reported in environmental matrices at concentrations ranging from nanograms per liter (ng/L) to milligrams per liter (mg/L). Agricultural soils, in particular, serve as a significant reservoir for antibiotic residues due to their strong particle adsorption capacities. Plants grown in soils irrigated with PhAC-contaminated water can uptake and accumulate these pharmaceuticals in various tissues, such as roots, leaves, and fruits, raising serious concerns regarding their consumption by humans and animals. There is an increasing need for research to understand the potential human health risks associated with the accumulation of antibiotics in the food chain. The present reviews aims to shed light on the rising environmental pharmaceutical contamination concerns, their sources in the environment, and the potential health risks as well as remediation effort. To discuss the main knowledge gaps and the future research that should be prioritized to achieve the risk assessment. We examined and summarized the available data and information on the antibiotic resistance associated with antibiotic residues in the environment. As studies have indicated that vegetables can absorb, transport, and accumulate antibiotics in edible parts when irrigated with wastewater that is either inadequately treated or untreated. These residues and their metabolites can enter the food chain, with their persistence, bioaccumulation, and toxicity contributing to drug resistance and adverse health effects in living organisms.

Determining nine fasciolicides and three metabolite residues in milk and infant formula using solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A new sensitive method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for nine fasciolicides (closantel, rafoxanide, oxyclozanide, niclosamide, nitroxinil, ioxynil, 4-nitro-3-(trifluoromethyl)phenol, salicylanilide, and triclabendazole) and three metabolite residues (ketotriclabnedazole, triclabendazole sulfone, and triclabendazole sulfoxide) in milk and infant formula was established. The samples were extracted and purified through solid-phase extraction and analyzed using LC-MS/MS. The proposed method demonstrated high accuracy (the average recoveries ranged from 70.5 % to 107.4 %) and high sensitivity (the limits of quantification ranged from 1.0 to 25.0 µg/kg). This method was successfully applied to determine nine fasciolicides and three metabolite residues in 45 milk and infant formula, providing technical support for the safety and quality evaluation of dairy products.

[Determination of five veterinary drug residues in milk by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry based on modified chitosan membrane purification].

Milk is an important consumer product with high nutritional value. The presence of veterinary drug residues in milk owing to the indiscriminate use of veterinary drugs may affect consumer health. In the mass spectrometric analysis of trace compounds, chromatographic co-eluting components easily interfere with the mass spectral signals obtained, affecting the accuracy of qualitative and quantitative analyses. Matrix purification is a promising method to reduce the matrix effect. Chitosan is a natural biopolymer with numerous active functional groups such as amino, acetyl, and hydroxyl groups; these groups can adsorb lipids through hydrophobic and electrostatic interactions. Chitosan also has the advantages of low production cost, stable chemical properties, and convenient modification. Novel chitosan-based materials are promising candidates for lipid purification. In this study, a chitosan membrane was modified with trimethoxyoctadecylsilane (C18-CSM). C18-CSM was prepared through one-step hydrolysis and used as a dispersive solid phase extraction (DSPE) adsorbent to purify the matrix during milk pretreatment. We combined C18-CSM with ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry (UHPLC-Q/Exactive Orbitrap MS) to develop an effective method for the extraction and determination of ofloxacin, enrofloxacin, ciprofloxacin, diazepam, and metronidazole in milk. C18-CSM was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle testing. The results indicated that the material has a rough surface and uniformly dense cross-section. The water contact angle of C18-CSM was 104°, indicating its good hydrophobicity. The pretreatment conditions (extraction solvent, dosage of NaCl, extraction frequency, and dosage of C18-CSM) that influenced the recoveries of the five veterinary drugs were investigated in detail. The optimal conditions were established as follows: 5% formic acid in acetonitrile, 1 g NaCl, extraction 1 time, 20 mg C18-CSM. Separation was performed on a Hypersil GOLD VANQUISH column (100 mm×2.1 mm, 1.9 µm). The mobile phase consisted of 0.1% formic acid aqueous solution and 0.1% formic acid in acetonitrile, and was flowed at a rate of 0.3 mL/min. The sample injection volume was 1 µL, and the column temperature was maintained at 25 ℃. Mass spectrometric analysis was performed in positive electrospray ionization mode. To verify the necessity of the purification material, the matrix effect was investigated using the matrix-matched standard curve method. The use of C18-CSM reduced the matrix effects of the five necessity drugs from the range of -22%-8.8% to the range of -13%-3.6%, indicating that C18-CSM is a highly efficient DSPE material. Under optimal conditions, the developed method showed good linearities within the range of 0.5-100 µg/L, with correlation coefficients (r2)≥0.9970. The limits of detection(LODs) and quantification (LOQs) were 0.2 µg/L and 0.5 µg/L, respectively. To assess the accuracy and precision of the method, we prepared milk samples with three spiked levels (low, medium, and high). The recoveries of the five veterinary drugs were ranged from 79.5% to 115%, and the intra-day and inter-day relative standard deviations were 7.0%-13% (n=6) and 1.3%-11% (n=3), respectively. This study provides a simple, accurate, and reliable method for the rapid and simultaneous determination of the five veterinary drug residues in milk.

Are pharmaceutical residues in crops a threat to human health?

The application of biosolids, manure, and slurry onto agricultural soils and the growing use of treated wastewater in agriculture result in the introduction of human and veterinary pharmaceuticals to the environment. Once in the soil environment, pharmaceuticals may be taken up by crops, resulting in consequent human exposure to pharmaceutical residues. The potential side effects of pharmaceuticals administered in human medicine are widely documented; however, far less is known regarding the risks that arise from incidental dietary exposure. The aim of this study was to evaluate human exposure to pharmaceutical residues in crops and assess the associated risk to health for a range of pharmaceuticals frequently detected in soils. Estimated concentrations of carbamazepine, oxytetracycline, sulfamethoxazole, trimethoprim, and tetracycline in soil were used in conjunction with plant uptake and crop consumption data to estimate daily exposures to each compound. Exposure concentrations were compared to Acceptable Daily Intakes (ADIs) to determine the level of risk. Generally, exposure concentrations were lower than ADIs. The exceptions were carbamazepine, and trimethoprim and sulfamethoxazole under conservative, worst-case scenarios, where a potential risk to human health was predicted. Future research therefore needs to prioritize investigation into the health effects following exposure to these compounds from consumption of contaminated crops.

Intra-species differences shape differences of enrofloxacin residues and its degradation products in tilapia: A precise risk assessment.

The increasing use and abuse of antibiotics in agriculture and aquaculture necessitates a more thorough risk assessment. We first advocate a precise assessment that subdivides the assessment scope from interspecies to intraspecific levels. Differences in ENR residues and degradation within the intraspecific category were simultaneously explored. This study chose red and GIFT tilapia, both belonging to the intra-specific category of tilapia, for an enrofloxacin (ENR) exposure experiment. Red tilapia had a lower area under the curve (AUC) representing drug accumulation, indicating a notably shorter withdrawal period (7 days) compared to GIFT tilapia (31.4 days) in the edible parts. While four potential transformation pathways were proposed for ENR in tilapia, red tilapia had fewer detected degradation products (6 items) than GIFT tilapia (10 items), indicating a simpler transformation pathway in red tilapia. Predictive assessments using the Toxtree model revealed that of the four extra degradation products in GIFT tilapia, two may possess carcinogenic and mutagenic properties. Overall, differences were observed in ENR residues and degradation within the intraspecific category, with red tilapia presenting lower risks than GIFT tilapia. This work suggests a new strategy to perfect the methodology for antibiotic risk assessment and facilitate systematic antibiotic administration management in the future.

Ion coordination and chelation in Eu-MOFs matrices: Ultrafast fluorescence visual quantification monitoring of antibiotic residues.

Rapid monitoring of trace antibiotics in the field in real time is essential for environment forewarning and human health. High sensitivity and real-time on-site quantitative monitoring of antibiotic residues can be accomplished by integrating portable sensors alongside fluorescent optics to construct an intelligent sensing platform that smoothly eliminates the instability of conventional detection methods. In this study, a ratiometric fluorescence sensor for the ultrasensitive detection of pefloxacin was built employing the photoinduced electron transfer (PET) mechanism from red Eu-MOFs to Mn2+-PEF complex. A visual color change results from the photoinduced electron transfer process from manganese ions to pefloxacin weakening the ligand metal charge transfer (LMCT) process in Eu-MOFs. This enables the ultrafast visible detection of pefloxacin and produces a transient shift in visual color with a detection limit as low as 15.4 nM. For the detection of pefloxacin in water, tomato, and raw pork samples, various sensing devices based on the developed fluorescent probes exhibit good practicability and accuracy. With the development of the ratiometric fluorescence sensing probe, it is now possible to quickly and quantitatively identify pefloxacin residues in the environment, offering a new method for ensuring the safety of food and people's health.

Combining Vis-NIR and NIR hyperspectral imaging techniques with a data fusion strategy for prediction of norfloxacin residues in mutton.

Norfloxacin is an antibacterial compound that belongs to the fluoroquinolone family. Currently, hyperspectral imaging (HSI) for the detection of antibiotic residues focuses mostly on individual systems. Attempts to integrate different HSI systems with complementary spectral ranges are still lacking. This study investigates the feasibility of applying data fusion strategies with two HSI techniques (Visible near-infrared and near-infrared) in combination to predict norfloxacin residue levels in mutton. Spectral data from the two spectral techniques were analyzed using partial least squares regression (PLSR), support vector regression (SVR) and stochastic configuration networks (SCN), respectively, and the two data fusion strategies were fused at the data level (low-level fusion) and feature level (middle-level fusion, mid-level fusion). The results indicated that the modeling performance of the two fused datasets was better than that of the individual systems. Mid-level fusion data achieved the best model based on uninformative variable elimination (UVE) combined with SCN, in which the determination coefficient of prediction set (R2p) of 0.9312, (root mean square error of prediction set) RMSEP of 0.3316 and residual prediction deviation (RPD) of 2.7434, in comparison with all others. Therefore, two HSI systems with complementary spectral ranges, combined with data fusion strategies and feature selection, could be used synergistically to improve the detection of norfloxacin residues. This study may provide a valuable reference for the non-destructive detection of antibiotic residues in meat.

Optimal conditions for determination of bacitracin, bacitracin zinc and bacitracin methylene disalicylate in animal feed by ultra-performance liquid tandem mass spectrometry.

An integrated method combining solid-phase extraction (SPE) with ultra-performance liquid tandem mass spectrometry (UPLC-MS/MS) has been established for quantifying bacitracin (BTC), bacitracin zinc (BZ), and bacitracin methylene disalicylate (BMD) in animal feed. A pretreatment procedure that can effectively, quickly, and simultaneously extract and purify BTC, BZ, or BMD in feed was developed for the first time through the optimization of extraction and SPE conditions. After extraction with acetonitrile + methanol + 15 % ammonia solution (1:1:1, v:v:v) and dilution with EDTA solution (1.5 mmol/L, pH 7.0), a SPE procedure was carried out with C18 cartridge. Following LC-MS/MS analysis utilized a Waters Peptide BEH C18 column with a gradient elution of 0.1 % formic acid in water/acetonitrile with. This method demonstrated a strong linear correlation (R2 > 0.9980) across a 0.01-1.0 mg/L concentration span, based on a matrix-matched standard curve. Satisfactory recoveries of BTC (bacitracin A, B1, B2, and B3), BZ, and BMD in different feeds were obtained from 80.7 % to 108.4 %, with relative standard deviations below 15.7 %. Low limits of quantification ranging within 7.2-20 µg/kg were achieved for bacitracin A, B1, B2, and B3. This method provided an effective and reliable detection method to prevent the addition of BTC and different BTC formulations in feeds.

Advancements and greenification potential of magnetic molecularly imprinted polymers for chromatographic analysis of veterinary drug residues in milk.

Milk, as a widely consumed nutrient-rich food, is crucial for bone health, growth, and overall nutrition. The persistent application of veterinary drugs for controlling diseases and heightening milk yield has imparted substantial repercussions on human health and environmental ecosystems. Due to the high demand, fresh consumption, complex composition of milk, and the potential adverse impacts of drug residues, advanced greener analytical methods are necessitated. Among them, functional materials-based analytical methods attract wide concerns. The magnetic molecularly imprinted polymers (MMIPs), as a kind of typical functional material, possess excellent greenification characteristics and potencies, and they are easily integrated into various detection technologies, which have offered green approaches toward analytes such as veterinary drugs in milk. Despite their increasing applications and great potential, MMIPs' use in dairy matrices remains underexplored, especially regarding ecological sustainability. This work reviews recent advances in MMIPs' synthesis and application as efficient sorbents for veterinary drug extraction in milk followed by chromatographic analysis. The uniqueness and effectiveness of MMIPs in real milk samples are evaluated, current limitations are addressed, and greenification opportunities are proposed. MMIPs show promise in revolutionizing green analytical procedures for veterinary drug detection, aligning with the environmental goals of modern food production systems.

Validation of the method for determining lincomycin levels and calculating lincomycin levels in broiler chicken plasma using high-performance liquid chromatography.

Background: Antibiotic residues that come from food of animal origin, such as broiler chicken, have a variety of consequences on human health and increase the likelihood of antibiotic resistance. Lincomycin residue investigations in broiler chicken especially in plasma broiler chicken should be undertaken utilizing the validation method analysis. Aim: The purpose of this study is to determine the high-performance liquid chromatography (HPLC) as a validation method for calculating the residual concentration of lincomycin in broiler chicken blood plasma and compare it with the minimum Inhibitor Concentration (MIC) and Maximum Residue Limits (MRLs) standards for lincomycin. Methods: Thirty-five-day-old broiler chickens cobb 700 were weighed and randomly allocated to and separated into control (placebo) and six treatment groups of varying doses and duration. The treatment group's suggested dosage of lincomycin was 50, 100, or 150 mg/kg/day given to 18-day-old chicken, along with drinking water for a week (A group) and 2 weeks (P group). Lincomycin levels in blood plasma were validated using HPLC. The residual lincomycin concentrations 24 hours and 1 week after injection were compared to the lincomycin MIC and the Indonesian National Standard of MRL. Result: The validation of linscomycin reveals a linear value in blood plasma with an R2 of 0.9983. Precision and accuracy levels indicate promising results for detecting lincomycin. The retention duration for 100 µg/ml lincomycin was 10.0-10.5 minutes. Lincomycin had LOD and LOQ values of 13.98 and 4.86 µg/ml, respectively. After 1 week of dosing at 50 and 100 mg/kg dosages, lincomycin residue detection was 0.00, which was below the MRL criterion of <0.1 ppm. The study found that the residual concentration of 150 mg/kg dosages for a week and 100/150 mg/kg doses for 2 weeks above the lincomycin MIC limits against Mycoplasma synoviae, Staphylococcus aureus, and Salmonella enteritidis. Conclusion: Lincomycin detection by HPLC in chicken blood plasma showed promising results in terms of linearity, accuracy, precision, specificity, and sensitivity. Lincomycin administration for 1 week at doses of 50 and 100 mg/kg resulted in the lowest residual concentration below the lincomycin MIC and MRL standards.

[A colloidal gold immunochromatography-based method for detecting enramycin residues in feed].

To achieve rapid detection of enramycin in feed, we employed the competitive inhibition method to develop a colloidal gold immunochromatographic test strip based on the anti-enramycin A monoclonal antibody (anti-Er.A-mAb). Colloidal gold probes were prepared with a laboratory-prepared high-purity anti-Er.A-mAb. The effects of pH, antibody titer, and antigen concentration (test line) on the test strip performance were investigated. The colloidal gold test strip prepared with 8 µL potassium carbonate addition, 4 µg/mL antibody, 1.0 mg/mL antigen (test line), and 3 µL gold-labeled antibody showed acceptable specificity and a low limit of detection. The test strip showed the detection limit of 25 ng/mL for enramycin A, with a linear range of 25-300 ng/mL. The experiments on the feed with positive sample addition proved that the test strip had good repeatability and was more sensitive than high-performance liquid chromatography, being applicable for the rapid detection of enramycin in large batches of feed samples.

A Cost-Effective and Sensitive Method for the Determination of Lincomycin in Foods of Animal Origin Using High-Performance Liquid Chromatography.

BACKGROUND: Lincomycin (LIN) is extensively used for treating diseases in livestock and promoting growth in food animal farming, and it is frequently found in both the environment and in food products. Currently, most of the methods for detecting lincomycin either lack sensitivity and precision or require the use of costly equipment such as mass spectrometers. RESULT: In this study, we developed a reliable high-performance liquid chromatography-ultraviolet detection (HPLC-UVD) method and used it to detect LIN residue in 11 types of matrices (pig liver and muscle; chicken kidney and liver; cow fat, liver and milk; goat muscle, liver and milk; and eggs) for the first time. The tissue homogenates and liquid samples were extracted via liquid-liquid extraction, and subsequently purified and enriched via sorbent and solid phase extraction (SPE). After nitrogen drying, the products were derivatized with p-toluene sulfonyl isocyanic acid (PTSI) (100 µL) for 30 min at room temperature. Finally, the derivatized products were analyzed by HPLC at 227 nm. Under the optimized conditions, the method displayed impressive performance and demonstrated its reliability and practicability, with a limit of detection (LOD) and quantification (LOQ) of LIN in each matrix of 25-40 µg/kg and 40-60 µg/kg, respectively. The recovery ranged from 71.11% to 98.30%. CONCLUSIONS: The results showed that this method had great selectivity, high sensitivity, satisfactory recovery and cost-effectiveness-fulfilling the criteria in drug residue and actual detection requirements-and proved to have broad applicability in the field of detecting LIN in animal-derived foods.

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Antibiotics are widely utilized in agriculture for the prevention and treatment of animal diseases. How-ever, the abuse and overuse of antibiotics progressively increase the risks of antibiotic residues and antibiotic resis-tance. The bioaccumulation and biomagnification of antibiotics through food chains will negatively affect ecological safety, and finally threaten human health. There are many shortages of traditional antibiotic detection techniques, such as complex procedures, complicated operation and time consuming, and thus are difficult to meet the demand of instant, efficient and accurate on-site detection. Therefore, it is crucial to develop rapid detection techniques of antibiotics to manage the application of antibiotics in agriculture. We reviewed the utilization, and management of antibiotics in animal husbandry, residual characteristics, and potential hazards of antibiotics in agricultural products, summarized the advancements in rapid detection techniques of antibiotics in agricultural products over the past five years, compared the advantages and disadvantages of different rapid detection techniques, and prospected the future development in this area. This review would provide a valuable reference to the control and point-of-care test of antibiotics in agricultural products.

Development and performance evaluation of a microbiological method for screening and LC-MS/MS for conformation of sulfonamides in animal-derived foods.

This study developed a highly sensitive microbiological method utilizing a novel microtiter plate to screen 10 sulfonamides in chicken muscles, eggs, and prawns. This plate was fabricated from agar incorporating trimethoprim and spread with Bacillus megaterium. After residue detection by bioassay, the same test solutions were analyzed by LC-MS/MS for accurate identification and quantification. It also proved eco-friendly compared to using other quantitative methods. The residual drugs were extracted with McIlvaine buffer and purified using an Oasis® MCX cartridge. A triethylamine/methanol/water (0.5:75:24.5, v/v/v) mixture was used as the eluate. The obtained LOD values of the bioassay ranged from 5 to 25 µg kg-1 allowing the detection of the target drugs at the MRLs established in Japan. Adhering to ISO/IEC 17025 standards, the performance of the bioassay was evaluated. Based on the inhibition zone size in bioassay results, quality control yielded a Z score within ±2, indicating reasonable control over the screening process. Proficiency testing of a chicken muscle sample spiked with sulfadimidine demonstrated the inhibition zone detection of the bioassay and quantified value alignment of LC-MS/MS with reference values. In a surveillance study of 91 samples, sulfamethoxazole was detected in one prawn sample.

Residue depletion of enrofloxacin and flumequine in feathers of broilers based on quantitative UHPLC-MS/MS detection.

To explore potential factors contributing to high fluoroquinolone resistance levels, it is essential to develop analytical methods capable of detecting residues and trace amounts of antibiotic use in broilers. The aim of the present study was to develop and in-house validate a sensitive UHPLC-MS/MS method capable of determining enrofloxacin (ENR) and flumequine (FLU) residues at slaughter age (day 45) when the animals were treated with these antimicrobials one day after hatching. Residue depletion of ENR and FLU in feathers was also assessed. Two experimental trials were performed, both consisting of 5 different treatment groups. In the first trial animals were treated with ENR and in the second one with FLU. The developed method was successfully validated and was found to be sensitive enough to detect residues of fluoroquinolones in the feathers up until slaughter age in all treatment groups. Average ENR concentration on day 45 was 10 ng g-1 feather after drinking water treatment, with all concentrations above the limit of quantification (LOQ) of 5 ng g-1 feather. For FLU average concentration on day 45 after drinking water administration was 4 ng g-1 feather, with an LOQ of 1 ng g-1 feather. Therefore, the method is suited for application to monitor fluoroquinolone use in broilers.

Hypersensitive electrochemical sensor based on thermally annealed gold-silver alloy nanoporous matrices for the simultaneous determination of sulfathiazole and sulfamethoxazole residues in food samples.

In this study, we have developed a novel, hypersensitive, and ultraselective electrochemical sensor containing thermally annealed gold-silver alloy nanoporous matrices (TA-Au-Ag-ANpM) integrated with f-MWCNTs-CPE and poly(l-serine) nanocomposites for the simultaneous detection of sulfathiazole (SFT) and sulfamethoxazole (SFM) residues in honey, beef, and egg samples. TA-Au-Ag-ANpM/f-MWCNTs-CPE/poly(l-serine) was characterized using an extensive array of analytical (UV-Vis, FT-IR, XRD, SEM, and EDX), and electrochemical (EIS, CV and SWV) techniques. It exhibited outstanding performance over a wide linear range, from 4.0 pM to 490 µM for SFT and 4.0 pM to 520 µM for SFM, with picomolar detection and quantification limits (0.53 pM and 1.75 pM for SFT, 0.41 pM and 1.35 pM for SFM, respectively). The sensor demonstrated exceptional repeatability, reproducibility, and anti-interference capability, with percentage recovery of 95.6-102.4% in food samples and RSD below 5%. Therefore, the developed sensor is an ideal tool to address the current antibiotic residue crisis in food sources.

A novel fluorescence immunoassay for the quantitative detection of florfenicol in animal-derived foods based on ZnCdSe/ZnS quantum dot labelled antibody.

Florfenicol (F), an antimicrobial agent exclusive to veterinary use within the chloramphenicol class, is extensively applied as a broad-spectrum remedy for animal diseases. Despite its efficacy, concerns arise over potential deleterious residues in animal-derived edibles, posing threats to human health. This study pioneers an innovative approach, introducing a quantum dot fluorescence-based immunoassay (FLISA) for the meticulous detection of F residues in animal-derived foods and feeds. This method demonstrates heightened sensitivity, with a detection limit of 0.3 ng/mL and a quantitative detection range of 0.6-30.4 ng/mL. Method validation, applied to diverse food sources, yields recoveries from 90.4 % to 109.7 %, featuring RSDs within 1.3 % to 8.7 %, the results showed high consistency with the national standard HPLC-MS/MS detection method. These findings underscore the method's accuracy and precision, positioning it as a promising tool for swift and reliable F residue detection, with substantial implications for fortifying food safety monitoring.

Rapid and Online Microvolume Flow-Through Dialysis Probe for Sample Preparation in Veterinary Drug Residue Analysis.

A rapid and online microvolume flow-through dialysis probe designed for sample preparation in the analysis of veterinary drug residues is introduced. This study addresses the need for efficient and green sample preparation methods that reduce chemical waste and reagent use. The dialysis probe integrates with liquid chromatography and mass spectrometry (LC-MS) systems, facilitating automated, high-throughput analysis. The dialysis method utilizes minimal reagent volumes per sample, significantly reducing the generation of solvent waste compared to traditional sample preparation techniques. Several veterinary drugs were spiked into tissue homogenates and analyzed to validate the probe's efficacy. A diagnostic sensitivity of >97% and specificity of >95% were obtained for this performance evaluation. The results demonstrated the effective removal of cellular debris and particulates, ensuring sample integrity and preventing instrument clogging. The automated dialysis probe yielded recovery rates between 27 and 77% for multiple analytes, confirming its potential to streamline veterinary drug residue analysis, while adhering to green chemistry principles. The approach highlights substantial improvements in both environmental impact and operational efficiency, presenting a viable alternative to conventional sample preparation methods in regulatory and research applications.

Quick and high-throughput quantification of ß-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg using dispersive solid phase extraction.

A reliable liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS) method was developed for the simultaneous identification and quantification of 13 ß-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg. Dispersive-solid phase extraction (d-SPE) using acetonitrile (ACN) was used to prepare the samples. The analyte in the extracts was separated on a reversed-phase Accucore aQ (50 mm × 2.1 mm, 2.6 µm) using a mobile phase of an aqueous solution containing 2 mM ammonium acetate and acetonitrile (ACN) 0.1 % formic acid. The method was validated in accordance with Commission Implementing Regulation (CIR) EU 2021/808 at six different concentrations ranging from 0.1 to 5 µg/kg. The mean recoveries ranged from 65 to 94 %, while repeatability and reproducibility values were all below 13 %. The linearity, as correlation coefficients (R2) ranged from 0.9955 to 0.9999. The decision limit (CCα) and detection capability (CCß) ranges were 0.11-0.13 µg/kg and 0.12-0.15 µg/kg, respectively. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.004-0.048 µg/kg and 0.010-0.075 µg/kg, respectively. Of the 180 samples that were collected from local markets in Egypt, 21.11 % had ß-agonist residues. The mean concentration (µg/kg) and detection frequency (%) of the most frequently found ß-agonist in the samples were as follows: terbutaline (2.63 µg/kg and 90 %), ractopamine (5.14 µg/kg and 23.3 %). The method's applicability was verified by successfully completing two rounds of proficiency testing (PT).

Simultaneous determination of 68 antimicrobial compounds in pigs oral fluid by ultra-high performance liquid chromatography-tandem mass spectrometry.

Improper use of antimicrobials in veterinary medicine can lead to residues in food of animal origin. Post-mortem monitoring of antibiotics in animal products is carried out as part of official EU programmes on food safety and consumer health. Oral fluid testing is a promising surveillance method to monitor appropriate treatment in pigs and to avoid residues in edible tissues. Oral fluid analysis can be implemented in an antibiotic residue control programme, thus preventing economic losses due to meat disposal as a result of drug detection in tissues after the withdrawal period. An analytical method was developed for the analysis of 68 compounds from 12 groups (penicillins, cephalosporins, sulfonamides, macrolides, fluoroquinolones, tetracyclines, aminoglycosides, pleuromutilins, diaminopyrimidines, lincosamides, polypeptides and sulfones) in pig oral fluid. Extraction of antibacterials was performed with 0.5 % formic acid. Analyses were carried out by ultra-high performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-MS/MS) detection. The chromatographic separation was achieved on a Zorbax analytical column (2.1 × 50 mm) with a mobile phase consisting of acetonitrile and heptafluorobutyric acid (HFBA). The total run time was 7 min. The method was validated as a confirmatory method according to the Commission Implementing Regulation (EU) 2021/808. The reliability of the method was verified by testing real samples from pig farms.