Status of antibiotic residues in milk and dairy products of Iran: a systematic review and meta-analysis.

Background: Today, antibiotics are widely used for treatment and feed additives to enhance livestock growth. Antibiotic residues may be found in food of animal origin for various reasons, including ignoring the withdrawal period after treatment, overuse for animals, and contamination of feed with treated animals in animal products. Among animal products, dairy products have a special place in the human diet, and antibiotic residues in them have caused a great deal of concern among consumers. Objective: This systematic review and meta-analysis aimed to evaluate and compare studies conducted in Iran on antibiotic residues in dairy products during 2000-2022. Methods: In this review, 52 eligible studies were collected by searching the Scientific Information Database (SID), Magiran, Google Scholar, Science-Direct, Scopus, and PubMed using the English or Persian keywords such as an antibiotic or antimicrobial residue, Beta-lactam residue, Tetracycline residue, Sulfonamide residue, Chloramphenicol residue, Aminoglycosides residue, Macrolide residue, Quinolones residue, Milk, Raw milk, Pasteurized milk, UHT milk, Powder milk, Cheese, Yogurt, Butter, Cream, Doogh, Kashk, Ice cream, and Iran. Results: According to the reviewed studies, the total prevalence of antibiotic residues in dairy products was 29% (95% CI: 15-43%). Among the seven evaluated antibiotic groups, most studies have been conducted on tetracycline, beta-lactam, and sulfonamide groups, with 16, 10, and 7 respectively, and the highest level of contamination with 663 ± 1540 µg/l is related to tetracycline. Most studies on antibiotic dairy product residues in Iran with 12, 11, and 8 studies are associated with East Azarbaijan province, then Tehran and Khorasan Razavi respectively, and no study has been conducted in 11 provinces of the country. According to the studies, Gilan, Qazvin and Razavi Khorasan provinces had the highest amount of antibiotic residue in milk with an average value of 56.415 ± 33.354, 45.955 ± 4.179 and 45.928 ± 33.027, respectively. Most of the methods used in the studies to measure antibiotic residues in milk were the Copan test kit and the HPLC method, which were used in 19 and 14 studies, respectively. Conclusions: Studies have shown that the prevalence of antibiotic residue in dairy products in Iran is high, so applying an effective strategy and developing the necessary standards in this field to control milk quality is a public health necessity. The findings of this study show that further evaluation of fermented dairy products, especially non-fermented ones such as butter and cream, is needed to prevent adverse health reactions.

Veterinary Drug Residues in the Food Chain as an Emerging Public Health Threat: Sources, Analytical Methods, Health Impacts, and Preventive Measures.

Veterinary medications are necessary for both contemporary animal husbandry and food production, but their residues can linger in foods obtained from animals and pose a dangerous human risk. In this review, we aim to highlight the sources, occurrence, human exposure pathways, and human health effects of drug residues in food-animal products. Following the usage of veterinary medications, pharmacologically active compounds known as drug residues can be found in food, the environment, or animals. They can cause major health concerns to people, including antibiotic resistance development, the development of cancer, teratogenic effects, hypersensitivity, and disruption of normal intestinal flora. Drug residues in animal products can originate from variety of sources, including water or food contamination, extra-label drug use, and ignoring drug withdrawal periods. This review also examines how humans can be exposed to drug residues through drinking water, food, air, and dust, and discusses various analytical techniques for identifying these residues in food. Furthermore, we suggest some potential solutions to prevent or reduce drug residues in animal products and human exposure pathways, such as implementing withdrawal periods, monitoring programs, education campaigns, and new technologies that are crucial for safeguarding public health. This review underscores the urgency of addressing veterinary drug residues as a significant and emerging public health threat, calling for collaborative efforts from researchers, policymakers, and industry stakeholders to develop sustainable solutions that ensure the safety of the global food supply chain.

Simultaneous detection of residues of 34 beta-lactam antibiotics in livestock and fish samples through liquid chromatography-tandem mass spectrometry.

ß-Lactam is one of the widely used veterinary drugs, but simultaneous analytical methods for ß-lactam on various animal foods have not been established. In this study, we aimed to detect 34 ß-lactam antibiotics simultaneously in livestock samples (beef, pork, chicken, egg, and milk) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted using phosphate buffer/acetonitrile or water/acetonitrile and then cleaned with 150 mg of C18 and 900 mg of MgSO4. The method showed acceptable recovery and repeatability of 66.1-119% and 1.5-26%, respectively. The method was employed to monitor 127 real samples from the domestic market to confirm its applicability, and no ß-lactam residues were detected. It was also applied to other matrices (eel, flat fish, and shrimp) and showed acceptable recovery (62.1-120%) and repeatability (1.0-28%). The method is expected to improve the efficiency of monitoring veterinary drug residues in domestic livestock products and fishery foods.

Antibiotic residues and microbial contamination in pasteurized whole milk intended for human consumption.

Background and Aim: Milk contamination for human consumption is one of the biggest concerns worldwide. To prevent milk contamination, it is important to implement sustainable production practices that ensure animal health and guarantee veterinary drugs have been used properly. This study aimed to detect antibiotic residues and microbial contamination in commercially available pasteurized whole milk intended for human consumption. Materials and Methods: We conducted a cross-sectional study on all brands of pasteurized milk (n = 17) for human consumption in Medellín, Colombia, from February 30 to April 30, 2022. Six milk samples of each brand were collected every 15 days, resulting in 102 samples. IDEXX SNAPduo™ ST Plus test (IDEXX Laboratories Inc, Maine, USA) was used to detect cephalosporins residues to detect beta-lactam and tetracyclines. We detected mesophilic aerobic bacteria and coliforms using Chromocult Coliform Agar® (Merck KGaA, Darmstadt, Germany) and Plate-Count Agar® (Merck KGaA), respectively. Results: Beta-lactam residues were found in 24.4% of the brands. No tetracyclines or cephalosporins were detected. Mesophilic aerobic bacteria and coliform contamination were detected in 42.6% and 12.8% of the brands, respectively. No fecal coliform contamination was detected. Conclusion: This study demonstrated the presence of antibiotic residues and microbial contamination in commercially available pasteurized whole milk intended for human consumption in the study area, highlighting its potential public health implications.

In-tube solid phase extraction with graphitic-based polyurethane sponge as a superhydrophobic sorbent and determination of drug residues in foodstuffs using high-performance liquid chromatography.

Veterinary drugs used in animal husbandry raise public health concerns due to their residues in the bodies of animals. This study employs a simple and quick sample preparation technique, in-tube solid phase extraction, to extract drug residues from foodstuffs, including eggs, honey, and water. This technique utilizes the synergy of graphitic-based materials and polyurethane sponges (PU) combined through dip coating method to make reusable sorbents for extracting drugs, including amoxicillin, paracetamol, ciprofloxacin, and cefixime. These prepared sorbents were characterized using FTIR, SEM, and XRD. HPLC analysis assessed the extraction efficiency, considering various parameters such as analyte concentration, sample solution pH, extraction time, type of eluting solvent, and graphitic-based polyurethane sponge reusability and stability. The proposed method exhibited a linear response for all three sorbents in the range of 0.03-1000 µg mL-1, with LOD 0.03-1.60 µg mL-1 and LOQ 0.18-4.84 µg mL-1. The % RSD ranged from 1.3 to 9.3 %, with recoveries of up to 98.42 %.

Comparison of filter membranes in the analysis of 183 veterinary and other drugs by liquid chromatography-tandem mass spectrometry.

Although filtration is one of the most common steps in sample preparation for chemical analysis, filter membrane materials can leach contaminants and/or retain some analytes in the filtered solutions. In multiclass, multiresidue analysis of veterinary drugs, it is challenging to find one type of filter membrane that does not retain at least some of the analytes before injection in ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In this study, different filter membranes were tested for use in UHPLC-MS/MS analysis of 183 diverse drugs in bovine muscle, kidney, and liver tissues. Membranes evaluated consisted of polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVDF), polyethersulfone, nylon, and regenerated cellulose. Drug classes represented among the analytes included ß-agonists, ß-lactams, anthelmintics, macrolides, tetracyclines, sulfonamides, tranquilizers, (fluoro)quinolones, anti-inflammatories, nitroimidazoles, coccidiostats, phenicols, and others. Although the presence of a matrix helped reduce the binding of analytes on surface active sites, all of the filter types partially retained at least some of the drugs in the final extracts. In testing by flow-injection analysis, all of the membrane filters were also observed to leach interfering components. Ultimately, filtration was avoided altogether in the final sample preparation approach known as the quick, easy, cheap, effective, rugged, safe, efficient, and robust (QuEChERSER) mega-method, and ultracentrifugation was chosen as an alternative.

Analysis of 14 ß-agonists in pork using an automated wooden tip-based solid-phase microextraction device and ultra-high-performance liquid chromatography-tandem mass spectrometry.

This study introduces a cost-effective, automated ultra-high-performance liquid chromatography-tandem mass spectrometry method for the detection of 14 ß-agonists in pork using a novel solid-phase microextraction probe composed of polyacrylonitrile and molecularly imprinted polymer. Integrated into an automated extraction device, the probe optimizes extraction prior to analysis while reducing expenses and time compared to traditional solid-phase extraction procedures. The method validation followed the Chinese National Standard (GB/T 27404-2008) and examined limits of detection, limits of quantification, matrix effects, linearity, intraday, and interday precision. Average recovery rates ranged from 71.6% to 82.2%, with relative standard deviations less than 15%. Limits of detection and limits of quantification ranged from 0.09 to 0.39 and 0.27 to 0.99 µg/kg, respectively. The new method identified positive samples more accurately than the current National Standard GB/T 31658.22-2022 and demonstrated its potential for routine assessment and regulatory compliance in the detection of ß-agonists in pork.

Development, validation, and implementation of an ultratrace analysis method for the determination of moenomycin A, in aquatic animal products.

Moenomycin A, an antimicrobial growth promoter widely used as an additive in aquaculture feedstuffs, has been restricted for use in the European Union and China due to its potential risk of promoting resistant strains of pathogenic bacteria and causing residues in aquatic animal products. Although methods for analyzing moenomycin A in feedstuffs have been developed, no established method exists for aquatic matrices. In this study, we present, for the first time, a sensitive and validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of moenomycin A in aquatic animal products. Samples were extracted using methanol and purified with the QuEChERS method employing C18 sorbent. The aliquot was dried under a nitrogen stream, reconstituted with methanol-water solvent, and analyzed by HPLC-MS/MS. The developed method exhibited good linearity (r2 > 0.995) over a wide concentration range (1-100 µg/L) and a low limit of detection (1 µg/kg). Average recoveries ranged between 70 and 110% at spiked concentrations of 1, 50, and 100 µg/kg, with associated intra- and inter-day relative standard deviations of 1.25 to 7.32% (n = 6) and 2.91 to 10.08% (n = 3), for different representative aquatic animal production, respectively. To the best of our knowledge, this is the first reported HPLC-MS/MS method for the quantification of moenomycin A in aquatic animal products. The new approach was effectively employed in the analysis of moenomycin A across various aquatic samples.

Surveillance of veterinary drug residues in food commonly consumed in Singapore and assessment of dietary exposure.

Non-judicious and indiscriminate use of veterinary drugs in animal husbandry may result in accumulation of residues in animal tissues, and consequently in food for human consumption. The abuse of veterinary drugs presents a potential risk to consumer health, especially if the residue level is higher than the health-based guidance value (HBGV) such as the acceptable daily intake (ADI). Contamination of drug residues in food also promotes the emergence of antimicrobial resistance (AMR) which poses a serious threat to public health globally. There has been limited information on the occurrence and dietary exposure to veterinary drug residues in Singapore to date. In this study, the occurrence of four classes of veterinary drugs, namely beta-agonists, coccidiostats, fluoroquinolones and macrolides, were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in food widely consumed by Singapore residents. The magnitude of dietary exposure was assessed based on the consumption profile of Singapore population. Out of 216 food samples, 9.72 % were detected positive with veterinary drug residues, where majority of the positive samples were poultry and its derived products, followed by eggs and egg products. 7 veterinary drugs, specifically ciprofloxacin, enrofloxacin, clopidol, diclazuril, lasalocid, nicarbazin and tilmicosin, were detected in the samples, with clopidol and enrofloxacin being the most frequently detected drugs. Dietary exposure was evaluated using the estimated daily intake (EDI) of the detected drugs and benchmarked against the corresponding acceptable daily intake (ADI). All the %ADI values were far less than 100 in both the average and high consumer scenarios, indicating that the health risk associated with dietary exposure to these drugs in Singapore is low.

Novel filter-press single-step cleanup approach facilitated rapid screening and accurate quantification of 112 veterinary drugs in aquatic products.

In this study, a novel filter-press cleanup column was developed as a single-step cleanup approach for the rapid screening and quantification of 112 veterinary drugs in fish samples. Fish muscle samples were extracted with acetonitrile and ethyl acetate, sequentially. After concentration and reconstitution, N-propylethylenediamine (PSA) sorbent, packed in filter-press column, allows rapid single-step cleanup operation, while UHPLC-Q-Orbitrap-HRMS provides high-precision mass information in multi-residue screening. Under optimum settings, the detection and quantification limits were validated at 0.5 and 2.0 µg·kg-1, for all analytes, respectively. The ranges of recoveries were from 35.3 to 138.4%. Most of these target analytes (82%) could be measured with recoveries between 60 and 130%, and intra-day RSDs ranging from 1.9 to 26.1%. This method was further applied to evaluate the residual of veterinary drugs in fish samples from four cities in China, and results demonstrated its practicability for multi-residue monitoring veterinary residues for food safety administration.

A review on recent advances in mass spectrometry analysis of harmful contaminants in food.

Food safety is a widespread global concern with the emergence of foodborne diseases. Thus, establishing accurate and sensitive detection methods of harmful contaminants in different food matrices is essential to address and prevent the associated health risks. Among various analytical tools, mass spectrometry (MS) can quantify multiple impurities simultaneously due to high resolution and accuracy and can achieve non-target profiling of unknown pollutants in food. Therefore, MS has been widely used for determination of hazardous contaminants [e.g., mycotoxin, pesticide and veterinary drug residues, polychlorinated biphenyls (PCBs), dioxins, acrylamide, perfluorinated compounds (PFCs) and p-Phenylenediamine compounds (PPDs) in food samples]. This work summarizes MS applications in detecting harmful contaminants in food matrices, discusses advantages of MS for food safety study, and provides a perspective on future directions of MS development in food research. With the persistent occurrence of novel contaminants, MS will play a more and more critical role in food analysis.

Residue Depletion Profile and Estimation of Withdrawal Period for Sulfadimethoxine and Ormetoprim in Edible Tissues of Nile Tilapia (Oreochromis sp.) on Medicated Feed.

Sulfadimethoxine (SDM) and ormetoprim (OMP) are antimicrobials used in combination to treat bacterial infections in fish farming. The use of this drug combination is not yet regulated in some countries, such as Brazil. Due to the lack of regulated drugs for aquaculture in Brazil, this study investigated the residue depletion profile of SDM and OMP in Nile tilapia (Oreochromis sp.) after oral administration. Fish were treated with medicated feed containing a 5:1 ratio of SDM:OMP at the dose of 50 mg kg BW-1 for five consecutive days with an average water temperature of 28 °C. The drugs were incorporated into the feed by using a gelatin coating process which promoted homogeneity in drug concentration and prevented the drug leaching into the water during medication. The SDM and OMP determination in fish fillets (muscle plus skin in natural proportions) was performed using the QuEChERS approach followed by LC-MS/MS quantification. The analytical method was validated according to Brazilian and selected international guidelines. A withdrawal period of 9 days (or 252 °C days) was estimated for the sum of SDM and OMP residues at concentration levels below the maximum residue level of 100 µg kg-1.

A single exposure to sub-lethal concentrations of a glyphosate-based herbicide or fluoxetine-based agent on growth performance in Nile tilapia.

The aim of the present study was to determine e whether a single acute 96 hr exposure of a glyphosate-based herbicide (GBH) to Nile tilapia fingerlings affected growth performance during the first 90 days of culture. This association was considered as GBH increases serotoninergic activity that affect fish anorexically. Although these findings were based upon chronic investigations, this study was designed to examine whether a single, acute, but excessive concentration GBH might impair growth performance in fish. In parallel, fish were also exposed to fluoxetine (FLU), a drug that selectively inhibits the reuptake of serotonin in brain synapses, leading to increased serotoninergic activity. Data demonstrated a decreased growth performance in fingerlings exposed to GBH or FLU compared to unexposed fingerlings. In fact, FLU-exposed fingerlings exhibited lower average weight and length, diminished weight gain, which resulted in lower final biomass. GBH-exposed fish, despite displaying a lower mean body weight, exhibited a biomass similar to biomass on controls. These body weight differences were noted after 30-60- and 90-day growth period in clean water. In an aquaculture context, these observed changes may be considered harmful to the production or economic performance of large-scale farming as currently practiced in tilapia farming.

[Determination of 41 veterinary drug residues in livestock and poultry meat using a composite purification system coupled with direct analysis in real time-tandem mass spectrometry].

In a market environment where food safety problems still occur despite repeated prohibitions, food safety problems caused by veterinary drug residues and biological safety problems caused by the transfer of drug resistance have attracted much attention. Herein, a method based on a compound purification system coupled with direct analysis in real time-tandem mass spectrometry (DART-MS/MS) was established to determine 41 different types of veterinary drug residues in livestock and poultry products. First, a single-standard solution sampling method was used to optimize the selection of the best quasi-molecular ion, two daughter ions, and their cone-hole and collision voltages; qualitative and quantitative ion pairs are composed of a quasi-molecular ion and its corresponding daughter ion. The abundance ratios of the drug compounds in standard solutions of the solvent and matrix mixtures were then calculated according to the requirements of the European Union 2002/657 specification. DART-MS/MS was subsequently developed for the accurate characterization and quantitative analysis of the veterinary drugs. Finally, a composite purification pretreatment system was formed by combining the primary secondary amine (PSA) and octadecyl bonded silica gel (C18) of a QuEChERS technology with multiwalled carbon nanotubes (MWCNTs) to achieve the one-step purification of the drug compounds. The influence of the key parameters of the DART ion source on the determination of the drugs was investigated using the peak areas of the quantitative ions as the criterion. The optimum conditions were as follows: ion source temperature of 350 ℃, 12-Dip-it Samplers module, sample injection speed of 0.6 mm/s, and external vacuum pump pressure of -75 kPa. According to the differences in the dissociation constant (pKa) ranges of the 41 types of veterinary drug compounds and the characteristics of the sample matrixes, the extraction solvent, matrix-dispersing solvent, and purification method were optimized based on the recovery. The extraction solvent was 1.0% acetonitrile formate solution, and the pretreatment column included MWCNTs containing 50 mg of PSA and 50 mg of C18. The three chloramphenicol drugs showed a linear relationship in the ranges of 0.5-20 µg/L with correlation coefficients of 0.9995-0.9997,and the detection and quantification limits of three chloramphenicol drugs were 0.1 and 0.5 µg/kg, respectively. The 38 other drugs, including quinolones, sulfonamides, and nitro-imidazoles showed a linear relationship in the ranges of 2-200 µg/L with correlation coefficients of 0.9979-0.9999, and the detection and quantification limits of the 38 other drugs were 0.5 and 2.0 µg/kg, respectively. The recoveries of the 41 veterinary drugs at low, medium, and high spiked levels in chicken, pork, beef, and mutton samples were 80.0%-109.6%, with intra- and inter-day precisions of 0.3%-6.8% and 0.4%-7.0%, respectively. A total of 100 batches of animal meat (pork, chicken, beef, and mutton; 25 batches each) and known positive samples were simultaneously analyzed using the national standard method and the detection method established in this study. Sulfadiazine (89.2, 78.1, and 105.3 µg/kg) was detected in three batches of pork samples, and sarafloxacin (56.3, 102.0 µg/kg) was detected in two batches of chicken samples and no veterinary drugs were detected in the other samples; both methods yielded consistent results for known positive samples. The proposed method is rapid, simple, sensitive, environmentally friendly, and suitable for the simultaneous screening and detection of multiple veterinary drug residues in animal meat.

[Health risks from crop irrigation with treated wastewater containing antibiotic residues, resistance genes, and resistant microorganisms]. / Gesundheitsrisiken durch die Bewässerung von Nutzpflanzen mit aufbereitetem Abwasser, das Antibiotikarückstände, Resistenzgene und resistente Mikroorganismen enthält.

This review describes the effects and potential health risks of resistant microorganisms, resistance genes, and residues of drugs and biocides that occur when re-using wastewater for crop irrigation. It focusses on specific aspects of these contaminants and their interactions, but does not provide a general risk assessment of the microbial load when using reclaimed water.Antimicrobial residues, antimicrobial resistant microorganisms, and resistance genes are frequently detected in treated wastewater. They have effects on the soil and plant-associated microbiota (total associated microorganisms) and can be taken up by plants. An interaction of residues with microorganisms is mainly expected before using the water for irrigation. However, it may also occur as a combined effect on the plant microbiome and all the abundant resistance genes (resistome). Special concerns are raised as plants are frequently consumed raw, that is, without processing that might reduce the bacterial load. Washing fruits and vegetables only has minor effects on the plant microbiome. On the other hand, cutting and other processes may support growth of microorganisms. Therefore, after such process steps, cooling of the foods is required.Further progress has to be made in the treatment of wastewater that will be used for crop irrigation with respect to removing micropollutants and microorganisms to minimize the risk of an increased exposure of consumers to transferable resistance genes and resistant bacteria.

[Determination of amantadine, rimantadine and dimethylamantadine residues in poultry by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for determination of amantadine, rimantadine and dimethylamantadine residues in poultry matrix by ultra-performance liquid chromatography-tandem mass spectrometry. METHODS: Poultry samples were extracted with acid acetonitrile, salting out, and then the organic phase was cleaned up by C_(18) and PSA. A Waters ACQUITYTM UPLC HSS T3 column(100 mm×2.1 mm, 1.7 mm)was used for liquid chromatography separation, ESI positive ion scan was used with multiple reaction monitoring(MRM) mode and quantified by matrix-matched external standard method. RESULTS: At the spiked level of 0.5, 1.0 and 5.0 µg/kg, the recoveries of each compound were in the range of 81.3%-91.1% with the relative standard deviations of 6.5%-11.3%. The qualitative limits of detections were 0.06-0.2 µg/kg and the quantitative limits were 0.2-0.5 µg/kg for the 3 target compounds. The established method was applied to the detection of the 3 target compounds in 30 poultry samples, and none of the target compounds exceeded the residue limits. CONCLUSION: The method is simple, rapid, high sensitivity and good stability, with a wide variety and a certain development. It can be used for the daily monitoring of the veterinary drug residues in poultry.

SERS-active plasmonic metal NP-CsPbX3 films for multiple veterinary drug residues detection.

Sensitive and multiple veterinary drug residues detection is of important for food safety. Herein, uniform plasmonic Au nanobipyramids@Ag nanorods (Au NBP@Ag NR)-CsPbX3 films with strong surface-enhanced Raman scattering (SERS) activity were constructed. The effects of different CsPbX3 (X = Cl, Br, I, or mixed halogens) quantum dots (QDs) on the SERS performances of plasmonic metal NP films were investigated. CsPbI3 QDs with large dielectric constant could be served as the dielectric media to retard the attenuation of electromagnetic evanescent wave, inducing strong electromagnetic strength for SERS enhancement. Plasmon-induced metal-to-perovskite interfacial charge transfer transition also contributed to SERS enhancement. SERS-active plasmonic Au NBP@Ag NR-CsPbI3 films had excellent sensitivity and high reproducibility for quantitative, accurate and multiple detection of chloramphenicol, diazepam and malachite green in food matrix. This work deepened the understanding of the SERS enhancement mechanisms of plasmonic metal NP-perovskite hybrid heterostructures, showing potential prospects in food safety monitoring.

Introduction of multilayered magnetic core-dual shell SERS tags into lateral flow immunoassay: A highly stable and sensitive method for the simultaneous detection of multiple veterinary drugs in complex samples.

Direct, convenient, and sensitive monitoring of the residues of multiple drugs in complex environments is important but remains a challenge. Here, we report a surface-enhanced Raman scattering (SERS)-based multiplexed lateral flow immunoassay (LFA) that supports the simultaneous and sensitive detection of commonly used drugs kanamycin, ractopamine, clenbuterol, and chloramphenicol in unprocessed complex samples through the dual signal amplification strategy of numerous efficient hotspots and magnetic enrichment. Multilayered magnetic-core dual-shell nanoparticles (MDAu@Ag) with controllable subtle nanogaps were fabricated via the polyethyleneimine-mediated layer-by-layer (LBL) assembly of two layers of Au@Ag satellites onto superparamagnetic Fe3O4 cores and conjugated with specific antibodies as multifunctional tags in the LFA system for rapid capture, separation, and quantitative analysis. Two Raman reporters were embedded in internal nanogaps and modified on the surface of MDAu@Ag for the simultaneous and ultrasensitive detection of four targets on two test lines, which greatly simplified the fabrication and signal reading of SERS-LFA. The proposed assay can rapidly detect multiple drug residues in 35 min with detection limits down to pg/mL level. Moreover, the MDAu@Ag-based SERS-LFA demonstrated better stability, higher throughput, and superior sensitivity (at least 400 times) than traditional colloidal gold immunochromatography, showing its great potential in the field of point-of-care testing.

Target analysis and retrospective screening of contaminants in ready-to-eat cooked ham samples through UHPLC-Q-Orbitrap HRMS.

The use of veterinary drugs (VDs) is widely administered to animals for both therapeutic and prophylactic purposes. However, their improper use may involve their occurrence in the final products intended for human consumption. In this scientific work, a method for the investigation of target (n = 30) VDs residues and retrospective suspect screening followed by confirmation using analytical standards of others 38 contaminants in ready-to-eat cooked ham by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed. The extraction was performed based on the QuEChERS approach and validated in accordance with the European Regulation 2021/808. The application of the in-house validated method to ready-to-eat cooked ham showed the occurrence of fourteen VDs residues. Despite the important incidence, the concentration levels found were below the maximum residue limits set for VDs in porcine muscle, except for colchicine. Constant monitoring of animals derived food is strongly recommended to ensure the food safety of consumers.

[Determination of multi-veterinary drug residues in complementary foods for infants and young children by ultra performance liquid chromatography-tandem mass spectrometry].

Special attention must be paid to children and infants because health issues stemming from a poor immunologic system and low weight make them a vulnerable risk group. Complementary foods for infants and young children, which are a class of special dietary foods, are essential transitional foods for infants from lactation to adaptation to ordinary food. Some complementary foods for infants and young children are of animal origin such as fish, meat, and the liver, which may contain veterinary drug residues. Veterinary drugs are usually small-molecular-weight chemicals that are essential for treating infections, increasing production, and improving animal husbandry. However, abuse of these substances can provoke transfer to the food chain, leading to negative consequences for humans, especially infants and young children. For a more comprehensive safety supervision of infant supplementary foods, a method based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and used for the determination of 50 antibiotics and antivirals (grouped into six categories: fluoroquinolones, sulfonamides, macrolides, nitroimidazoles, chloramphenicols, and antivirals) in complementary foods for infants and young children. The matrix of complementary foods for infants and young children is complex and contains a large number of proteins and lipids, which poses a serious challenge for sample pretreatment. The Captiva EMR-Lipid solid-phase extraction (SPE) column is a new type of product that allows for selective and efficient lipid/matrix removal without negatively affecting the recovery of the analyte. In this study, samples were extracted with acidified acetonitrile and then purified using a Captiva EMR-Lipid SPE column. The target analytes were separated on a BEH C18 column by gradient elution using acetonitrile and water containing 0.1% (v/v) formic acid as the mobile phases. MS detection was performed with an electrospray source in the positive and negative modes in the multireaction monitoring (MRM) mode. The ion spray voltages were set at 5500 V and -4500 V in the positive and negative modes, respectively. The source temperature for both the ionization modes was set to 500 ℃. Instrumental parameters such as collision energy and declustering potential were optimized. The samples were quantified using the external standard method with matrix calibration curves to reduce the influence of the matrix effect on the quantitative results.The results showed that the 50 veterinary drug residues had good linear relationships in the range of 0.5 to 50 µg/L, with correlation coefficients higher than 0.995. The limits of detection (LODs) and quantification (LOQs) were in the range of 0.03-0.70 µg/kg and 0.09-2.33 µg/kg, respectively. The average recoveries for all the compounds under different matrices ranged from 64.37% to 119.3% at spiked levels of 5 µg/kg and 50 µg/kg, with relative standard deviations of less than 15%. Compared to QuEChERS, this method has a better purification effect. The recoveries of the 50 veterinary drugs extracted by this method were also much higher than those in the case of QuEChERS. This method was applied to the detection of 14 domestic and six imported infant supplementary foods. Sulfaquinoxaline, sulfamethazine, and tilmicosin were detected in one imported meat-based baby food. With its simple operation, high sensitivity and accuracy, and low sample quantity consumption, this method is suitable for the determination of multiveterinary drug residues in complementary foods for infants and young children. This study provides an effective analysis method for risk monitoring and troubleshooting of complementary foods for infants and young children, which is of great significance in ensuring the healthy growth of the next generation.