Molecularly imprinted solid-phase extraction for the determination of ten macrolide drugs residues in animal muscles by liquid chromatography–tandem mass spectrometry

Construction of a portable and sensitive electrochemical immunosensor for the rapid detection of erythromycin based on semiconductive bimetallic MOF

The sensitive determination of antibiotics in food products is vital for ensuring food safety and protecting human health. Herein, we have fabricated a novel electrochemical portable and sensitive electrochemical immunosensor for the efficient detection of erythromycin (ERY) containing in food stuffs. For this, a semiconductive cooper/ferric bimetallic metal-organic framework (scMOF), which was synthesized using 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) as linking ligand (denoted as CuxFe3-x(HHTP)2), was utilized simultaneously as the platform for anchoring antibody and for modifying the sprinted printed electrode (SPE) to construct the electrochemical immunosensor. The obtained scMOF, CuxFe3-x(HHTP)2, exhibited high porosity, promoted conductivity, and enhanced anchoring ability toward antibody. Thereby, the developed SPE immunosensor demonstrated the superior biosensing performance for the detection of ERY. Within a wide range from 1.0 fg mL-1 to 1.0 ng mL-1, the CuxFe3-x(HHTP)2-based portable SPE immunosensor had an ultralow detection limit of 0.69 fg mL-1, together with high selectivity, good reproducibility, and excellent long-term stability, as well as acceptable practicality. The present SPE immunosensor based on scMOFs not only provides an innovative biosensing strategy for the sensitive inspection of antibiotics, but also extends the application of scMOF in the field of food analysis.

Selective extraction and quantitative analysis of pyrroloquinoline quinone from food

Pyrroloquinoline quinone (PQQ) is a bioactive compound that has attracted significant attention due to its potential health benefits. In this study, we developed a new magnetic molecularly imprinted nanoparticle (MMIN) for the selective extraction and determination of PQQ from food samples. The MMIN was synthesized using a surface molecular imprinting technique with PQQ as the template molecule, Fe3O4 nanoparticles as the magnetic core, and methacrylic acid as the functional monomer. The MMIN exhibited high selectivity and affinity towards PQQ, allowing for efficient extraction and preconcentration of PQQ from complex food matrices. The extracted PQQ was then quantified using HPLC-DAD. The developed method showed good linearity (R2 = 0.9985) and low limits of detection (0.03 μg L-1). The accuracy and precision of the method were evaluated by analyzing spiked food samples, with average recoveries close to 89.8%. The MMIN also demonstrated good reusability, with negligible decrease in extraction efficiency after five cycles of use. Overall, the developed MMIN-based method provides a reliable and efficient approach for the analysis of PQQ in food samples.

A Robust Homogeneous Fluorescence Polarization Immunoassay for Rapid Determination of Erythromycin in Milk

Erythromycin (ERY) is one of the most common macrolides applied in veterinary medicine to treat diseases or as a feed additive for animal growth promotion. Long-term irrational use of ERY could lead to residues in animal-derived food and the emergence of drug-resistant strains, posing potential threats to human health. In this study, a highly sensitive, specific, robust, and rapid fluorescence polarization immunoassay (FPIA) for the determination of ERY in milk has been described. Herein, to achieve high sensitivity, five tracers of ERY with different fluorescein structures were synthesized and paired with three monoclonal antibodies (mAbs). Under the optimized conditions, the combination of mAb 5B2 and tracer ERM-FITC achieved the lowest IC₅₀ value in the FPIA with 7.39 μg/L for ERM. The established FPIA was used to detect ERY in milk, revealing a limit of detection (LOD) of 14.08 μg/L with recoveries of 96.08-107.77% and coefficients of variations (CVs) of 3.41-10.97%. The total detection time of the developed FPIA was less than 5 min from the addition of samples to the result readout. All the above results showed that the proposed FPIA in this study was a rapid, accurate, and simple method for the screening of ERY in milk samples.

Advances in solid-phase extraction techniques: Role of nanosorbents for the enrichment of antibiotics for analytical quantification

Antibiotics are life-saving medications for treating bacterial infections; however it has been discovered that resistance developed by bacteria against these incredible agents is the primary contributing factor to rising global mortality rates. The fundamental cause of the emergence of antibiotic resistance in bacteria is the presence of antibiotic residues in various environmental matrices. Although antibiotics are present in diluted form in environmental matrices like water, consistent exposure of bacteria to these minute levels is enough for the resistance to develop. So, identifying these tiny concentrations of numerous antibiotics in various and complicated matrices will be a crucial step in controlling their disposal in those matrices. Solid phase extraction, a popular and customizable extraction technology, was developed according to the aspirations of the researchers. It is a unique alternative technique that could be implemented either alone or in combination with other approaches at different stages because of the multitude of sorbent varieties and techniques. Initially, sorbents are utilized for extraction in their natural state. The basic sorbent has been modified over time with nanoparticles and multilayer sorbents, which have indeed helped to accomplish the desired extraction efficiencies. Among the current traditional extraction techniques such as liquid-liquid extraction, protein precipitation, and salting out techniques, solid-phase extractions (SPE) with nanosorbents are most productive because, they can be automated, selective, and can be integrated with other extraction techniques. This review aims to provide a broad overview of advancements and developments in sorbents with a specific emphasis on the applications of SPE techniques used for antibiotic detection and quantification in various matrices in the last two decades.

Heterogeneous adsorbent based on CeZrO2 nanoparticles doped magnetic graphene oxide used for vortex assisted magnetic dispersive solid phase extraction of erythromycin in chicken

A simple, fast, and efficient method of vortex assisted magnetic dispersive solid phase extraction for separation and pre-concentration of erythromycin in chicken samples prior to high LC-UV determination has been developed. The novel heterogeneous CeZrO₂ nanoparticles doped magnetic graphene oxide, for use as an efficient nanosorbent, was synthetised and applied for the adsorption of erythromycin. The synthetised nanosorbent was characterised using both Fourier-transform infra-red (FT-IR) and energy dispersive X-Ray (EDX) spectroscopy together with field emission scanning electron microscopy-EDX. To obtain the best extraction condition and maximum extraction efficiency of erythromycin, the effect of important parameters including pH, amount of sorbent, vortexing time, ionic strength, sample volume, and desorption conditions were investigated. At optimum conditions, a linear range of 0.25-300 µg kg^-1, LOD (S/N = 3) of 0.079 µg kg^-1, and LOQ (S/N = 10) of 0.270 µg kg^-1 were obtained. The precision of the method was established as having an RSD (%) at 100 µg kg^-1 of erythromycin for seven replicates of 2.6% and 3.2% for the intra-day and the inter-day, respectively. Recoveries over 94.0% confirmed a high capability of the proposed method for separation and determination of erythromycin residues in chicken being one of the most important animal products.

Surface molecularly imprinted solid-phase extraction for the determination of vancomycin and norvancomycin in milk by liquid chromatography coupled to tandem mass spectrometry

A simple and sensitive method based on surface molecularly imprinted solid-phase extraction (SMISPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to determine the residues of vancomycin (VCM) and norvancomycin (NVCM) in milk samples. The imprinted polymer prepared with teicoplanin as a virtual template can specifically recognize VCM and NVCM. The samples were purified with SMISPE and analyzed by LC-MS/MS in positive ionization mode. The results showed that the VCM and NVCM had a good linear correlation in the range of 0.5 μg/kg to 50 μg/kg. The recoveries of target analytes were from 83.3% to 92.1%, and the limits of quantification were both 1.0 μg/kg. The matrix effects of VCM and NVCM were -11.0% and -3.43%, respectively. The proposed method can efficiently eliminate the interference from matrix compounds and reduce baseline noise, which is useful for the monitoring of the residues of VCM and NVCM in milk samples.

Review on molecular imprinting technology and its application in pre-treatment and detection of marine organic pollutants

Molecular imprinting technology (MIT) has been considered as an attractive method to produce artificial receptors with the memory of size, shape and functional groups of the templates and has become an emerging technique with the potential in various fields due to recognitive specificity, high efficient selectivity and mechanical stability, which can effectively remove background interference and is suitable for the pre-treatment and analysis of trace level substances in complex matrix samples. Nearly 100 papers about the application of MIT in the detection of marine pollutants were found through Science Citation Index Expanded (SCIE). On this basis, combined with the application of MIT in other fields, the pre-treatment process of marine environmental samples was summarized and the potential of four types of different molecularly imprinted materials in the pre-treatment and detection of marine organic pollutants (including antibiotics, triazines, organic dyes, hormones and shellfish toxins) samples was evaluated, which provides the innovative configurations and progressive applications for the analysis of marine samples, and also highlights future trends and perspectives in the emerging research field.

Fate of antibiotics in engineered wastewater systems and receiving water environment: A case study on the coast of Hangzhou Bay, China

The occurrence of man-made antibiotics in natural environment has aroused attentions from both scientists and publics. However, few studies tracked antibiotics from their production site to the end of disposal environment. Taking the coastal region of Hangzhou Bay as the study area, the fate of 77 antibiotics from 6 categories in two-step wastewater treatment plants (WTPs, i.e. pharmaceutical WTP and integrated WTP) was focused; and the antibiotics in both dissolved and adsorbed phases were investigated simultaneously in this study. The ubiquitous occurrence of antibiotics was observed in the two-step WTPs, with antibiotic concentrations following the order of PWTP (LOQ - 1.0 × 10⁵ ng·L^-1) > IWTP_i (for industrial wastewater treatment, LOQ - 3.7 × 10³ ng·L^-1) > IWTP_d (for domestic sewage treatment, LOQ - 1.3 × 10³ ng·L^-1). And the types of antibiotics detected in excess sludge and suspended particles were in accordance with those in wastewater. Quinolones were invariably dominant in both dissolved and adsorbed fractions. High removal efficiencies (median values >50.0%) were acquired for the dissolved quinolones (except for DFX), tetracyclines, β-lactams, and lincosamides. Anaerobic/anoxic/oxic achieved the highest aqueous removal of antibiotics among the investigated treatment technologies in the three WTPs. PWTP and IWTP removed 9797 and 487 g·d^-1 of antibiotics, respectively; and a final effluent with 126.4 g·d^-1 of antibiotics was discharged into the effluent-receiving area (ERA) of Hangzhou Bay. Source apportionment analysis demonstrated that the effluents of IWTP_d and IWTP_d contributed respectively 39.3% and 8.9% to the total antibiotics in the ERA. The results illustrate quantitatively the antibiotic flows from engineered wastewater systems to natural water environment, on the basis of which the improvements of wastewater treatment technologies and discharge management would be put forward.

Eco-friendly ionic liquid imprinted polymer based on a green synthesis strategy for highly selective adsorption tylosin in animal muscle samples

A novel eco-friendly molecularly imprinted polymer (MIP) was proposed as solid-phase extraction (SPE) adsorbent to selective adsorption tylosin (TYL) in animal muscle samples. The MIP was synthesized in aqueous by using 1,4-butanediyl-3,3-bis-1-vinyl imidazolium chloride and 2-acrylamide-2-methylpropanesulfonic acid as bifunctional monomer. The obtained MIP had excellent selectivity towards TYL in water, and the maximum binding capacity can reach 123.45 mg g^-1. Combined with high-performance liquid chromatography, the presented MIP can be used as SPE sorbent to recognize and detect TYL in the range of 0.008 to 0.6 mg L^-1 (R² = 0.9995). The limit of detection and limit of quantification were 0.003 mg L^-1 and 0.008 mg L^-1, and the intraday and interday precision were 1.05% and 3.36%, respectively. Under the optimal condition, the established MIP-SPE-HPLC method was successfully applied to separate and determine trace TYL in chicken, pork, and beef samples with satisfactory recoveries ranged from 94.0 to 106.3%, and the MIP-SPE cartridge can be cycled at least 20 times. This study implies a promising green MIP-SPE-HPLC method for highly selective adsorption and analysis trace TYL in complex matrices.

Application of core-satellite polydopamine-coated Fe3O4 nanoparticles-hollow porous molecularly imprinted polymer combined with HPLC-MS/MS for the quantification of macrolide antibiotics

Core-satellite-structured magnetic nanosorbents (MNs) used for the selective extraction of macrolide antibiotics (MACs) were prepared in this study. The MNs (core-satellite polydopamine-coated Fe₃O₄ nanoparticles-hollow porous molecularly imprinted polymer) consisted of polydopamine-coated Fe₃O₄ nanoparticles (Fe₃O₄@PDA) "core" linked to numerous hollow porous molecularly imprinted polymer (HPMIP) "satellites" with bridging amine functional groups. It is worth mentioning that HPMIPs act as "anchors" for selectively capturing target molecules. Polymers were characterized using TEM, SEM, FT-IR, VSM, and TGA and applied as magnetic dispersive solid-phase extraction (MDSPE) sorbents for the enrichment of trace MACs from a complex food matrix prior to quantification by HPLC-MS/MS. Nanocomposites revealed outstanding magnetic properties (36.1 emu g^-1), a high adsorption capacity (103.6 μmol g^-1), selectivity (IF = 3.2), and fast kinetic binding (20 min) for MACs. The multiple advantages of the novel core-satellite-structured magnetic molecularly imprinted nanosorbents were confirmed, which makes us believe that the preparation method of the core-satellite MNs can be applied to other fields involving molecular imprinting technology.

Synthesis of molecularly imprinted polymers based on boronate affinity for diol-containing macrolide antibiotics with hydrophobicity-balanced and pH-responsive cavities

In this research, in order to separate and purify diol-containing macrolide antibiotics, like tylosin, from complex biological samples, molecularly imprinted polymer (MIP) based on boronate affinity for tylosin was synthesized by using precipitation polymerization method with 4-vinylphenylboronic acid (VPBA) and dimethyl aminoethyl methacrylate (DMAEMA) as pH-responsive functional monomers, and N,N'-methylene bisacrylamide (MBAA)/ ethylene glycol dimethacrylate (EGDMA) as the co-crosslinkers that balance the hydrophobicity of the MIP. The synthesized tylosin-MIP had the advantages of high adsorption capacity (120 mg/g), fast pH-responsiveness responsible for the accessibility of imprinted cavities, and high selectivity coefficient towards tylosin versus its analogues (2.8 versus spiramycin, 7.3 versus desmycosin) in an aqueous environment. The mechanism of boronate affinity between tylosin and VPBA in the form of charged hydrogen bonding was analyzed via density functional theory (DFT). MIPs were used to successfully separate diol-containing macrolides through molecularly imprinted solid phase extraction (MISPE). The results show that MIPs prepared in this method have a good application prospect in the separation and purification of the diol-containing macrolide antibiotics.

Determination of antibiotics in meat samples using analytical methodologies: A review

Antibiotics are widely used to prevent or treat some diseases in human and veterinary medicine and also as animal growth promoters. The presence of these compounds in foods derived from food-producing animals can be a risk for human health. Consequently, regulatory agencies have set maximum residue limits for antibiotics in food samples. Therefore, the development of novel methodologies for its determination in food samples is required. Specifically, the analysis and quantification of these substances in meat tissues is a challenge for the analytical chemistry research community. This is due to the complexity of the matrix and the low detection limits required by the regulatory agencies. In this sense, a comprehensive review on the development of new sample preparation treatments involving extraction, cleanup, and enrichment steps of antibiotics in meat samples in combination with sensitive and sophisticated determination techniques that have been carry out in the last years is necessary. Therefore, the aim of this work is to summarize the published methodologies for the determination of antibiotics from 2016 until the beginning of the second semester of 2020. The first part of this review includes an introduction about antibiotic families, followed by sample preparation and determination techniques applied to the different families. Finally, a detailed discussion of the current trends and the future possible perspectives in this field are also included.

Rapid and Simultaneous Analysis of Multiple Classes of Antimicrobial Drugs by Liquid Chromatography-Tandem Mass Spectrometry and Its Application to Routine Biomedical, Food, and Soil Analyses

Antimicrobial agents (AMAs) are widely exploited nowadays to meet the high demand for animal-derived food. It has a significant impact on the food chain whose end consumers are human beings. The burden of AMAs on humans comes from either meat or crops cultivated on soil containing high residual antibiotics, which are responsible for the global crisis of antibiotic resistance. Thus, the objective of this study was to design a selective and sensitive liquid chromatography-mass spectrometry (LC-MS)/MS-based simultaneous bioanalytical method for estimation of twenty AMAs in human plasma, raw meat, and soil samples. The selective extraction of all analytes from the above matrices was performed by the solid-phase extraction clean-up method to overcome the interferences. Analytes were separated on a Waters Symmetry Shield C18 (150 × 4.6 mm², 5 μm) column, using an isocratic solvent system of methanol-0.5% formic acid (80:20, v/v) with 0.75 mL/min flow rate. The average extraction recoveries for all analytes in plasma were ranged from 42.0 to 94.0% with relative standard deviations (RSDs) below ±15%. All of the validation parameters are in accordance with the United State Food and Drug Administration (USFDA) guidelines. Moreover, the method was also valid for a broad plasma concentration range and can be proposed as an excellent method for routine pharmacokinetic studies, therapeutic drug monitoring, clinical analysis, and detection and quantitation of AMA remnants in raw meat as a standard quality control test for human consumption.

A review of pretreatment and analysis of macrolides in food (Update Since 2010)

Macrolides are versatile broad-spectrum antibiotics whose activity stems from the presence of a macrolide ring. They are widely used in veterinary medicine to prevent and treat disease. However, because of their improper use and the absence of effective regulation, these compounds pose a threat to human health and the environment. Consequently, simple, quick, economical, and effective techniques are required to analyze macrolides in animal-derived foods, biological samples, and environmental samples. This paper presents a comprehensive overview of the pretreatment and analytical methods used for macrolides in various sample matrices, focusing on the developments since 2010. Pretreatment methods mainly include liquid-liquid extraction, solid-phase extraction, matrix solid-phase dispersion, and microextraction methods. Detection and quantification methods mainly include liquid chromatography (coupled to mass spectrometry or other detectors), electrochemical methods, capillary electrophoresis, and immunoassays. Furthermore, a comparison between the pros and cons of these methods and prospects for future developments are also discussed.

Preparation and characterization of molecularly imprinted polymers based on β-cyclodextrin-stabilized Pickering emulsion polymerization for selective recognition of erythromycin from river water and milk

Molecularly imprinted polymers were prepared via β-cyclodextrin-stabilized oil-in-water Pickering emulsion polymerization for selective recognition and adsorption of erythromycin. The synthesized molecularly imprinted polymers were spherical in shape, with diameters ranging from 20 to 40 µm. The molecularly imprinted polymers showed high adsorption capacity (87.08 mg/g) and adsorption isotherm data fitted well with Langmuir model. Adsorption kinetics study demonstrated that the molecularly imprinted polymers acted in a fast adsorption kinetic pattern and the adsorption features of molecularly imprinted polymers followed a pseudo-first-order model. Adsorption selectivity analysis revealed that molecularly imprinted polymers had a much better specificity for erythromycin than that for spiramycin or amoxicillin, and the relative selectivity coefficient values on the bases of spiramycin and amoxicillin were 3.97 and 3.86, respectively. The Molecularly imprinted polymers also showed a satisfactory reusability after four times of regeneration. In addition, molecularly imprinted polymers exhibited good adsorption capacities for erythromycin under complicated environment, that is, river water and milk. These results proved that the as-prepared molecularly imprinted polymers is a potent absorbent for selective recognition of erythromycin, and therefore it may be a promising candidate for practical applications, such as wastewater treatment and detection of erythromycin residues in food.

Sample treatment based on molecularly imprinted polymers for the analysis of veterinary drugs in food samples: a review

The use of veterinary drugs in medical treatments and in the livestock industry is a recurrent practice. When applied in subtherapeutic doses over prolonged times, they can also act as growth promoters. However, residues of these substances in foods present a risk to human health. Their analysis is thus important and can help guarantee consumer safety. The critical point in each analytical technique is the sample treatment and the analytical matrix complexity. The present manuscript summarizes the development, type of synthesis, characterization, and application of molecularly imprinted polymers in the separation, identification, and quantification techniques for the determination of veterinary drug residues in food samples in extraction, clean-up, isolation, and pre-concentration systems. Synthesized sorbents with specific recognition properties improve the interactions between the analytes and the polymeric sorbents, providing better analysis conditions and advantages in comparison with commercial sorbents in terms of high selectivity, analytical sensitivity, easy performance, and low cost analysis.

Preparation and Application of Molecularly Imprinted Monolithic Extraction Column for the Selective Microextraction of Multiple Macrolide Antibiotics from Animal Muscles

This study aimed to prepare a molecularly imprinted monolithic extraction column (MIMC) inside a micropipette tip by situ polymerization with roxithromycin as the dummy template. The polymers possessed excellent adsorption capacity and class-specificity to multiple macrolide drugs. MIMC was directly connected to a syringe for template removal and for the optimization of extraction conditions without any other post-treatment of polymers. A liquid chromatography-tandem mass spectrometric method was developed for the selective microextraction and determination of macrolide antibiotics in animal muscles based on MIMC. High recoveries of 76.1–92.8% for six macrolides were obtained with relative standard deviations less than 10.4%. MIMC exhibited better retention ability and durability when compared with the traditional C18 and HLB cartridges. The proposed method shows a great potential for the analysis of macrolide drugs at the trace level in animal foodstuffs.

Determination of Six Macrolide Antibiotics in Chicken Sample by Liquid Chromatography-Tandem Mass Spectrometry Based on Solid Phase Extraction

In this paper, a simple and effective method for the determination of six macrolide antibiotics (MACs), including tylosin, tilmicosin, azithromycin, clarithromycin, roxithromycin, and kitasamycin, in the chicken sample using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed based on a self-built porous aromatic framework- (PAF-) based solid phase sorbent. The main parameters influencing the extraction efficiency, such as sorbent amounts, type of the eluent, pH of the sample, and the eluent volume, were evaluated. Under the optimized condition, the limits of detection were from 0.2 to 0.5 μg·kg^-1. The recoveries of the method ranged from 82.1% to 101.4% with the relative standard deviations less than 11.1%. All the results demonstrated that the established method is potential for the determination of macrolide antibiotics in food safety analysis and monitoring.

Quick Multi-Class Determination of Residues of Antimicrobial Veterinary Drugs in Animal Muscle by LC-MS/MS

On the basis of the highly sensitive and selective liquid chromatography-tandem mass spectrometry technique, a generic extraction solvent and a sample dilution method was developed for the residue analysis of different polar veterinary drugs known as fluoroquinolones, sulfonamides, macrolides, and tiamulin in chicken muscle. The results showed that the matrix-matched calibration curves of all 10 compounds were in an effective linear relationship (r² ≥ 0.997) in the range of 0.2⁻100 μg L^-1. At three spiking levels of 2 (5), 50, and 100 μg kg^-1, average recoveries of analytes were between 67.1% and 96.6% with relative standard deviations of intra-day and inter-day below 20%. The limits of detection and limits of quantification of the method were in the range of 0.3⁻2.0 μg kg^-1 and 2.0⁻5.0 μg kg^-1, respectively, which were significantly lower than their maximum residue limits. In addition, the intensity of the target analytes and its corresponding matrix effects were obviously related to the sample dilution times (matrix concentration). There were no significant differences (p > 0.05) in the average content of almost any of the analytes in medicated chickens between this method and the method in the literature for determining analytes. Lastly, the proposed method was successfully applied for the simultaneous analysis of 10 common veterinary drugs in food animal muscle tissues.

Determination of Ten Macrolide Drugs in Environmental Water Using Molecularly Imprinted Solid-Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

With the extensive application of antibiotics in livestock, their contamination of the aquatic environment has received more attention. Molecularly imprinted polymer (MIP), as an eco-friendly and durable solid-phase extraction material, has shown great potential for the separation and enrichment of antibiotics in water. This study aims at developing a practical and economical method based on molecularly imprinted solid phase extraction (MISPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneously detecting ten macrolide drugs in different sources of water samples. The MIP was synthesized by bulk polymerization using tylosin as the template and methacrylic acid as the functional monomer. The MIP exhibited a favorable load-bearing capacity for water (>90 mL), which is more than triple that of non-molecularly imprinted polymers (NIP). The mean recoveries of macrolides at four spiked concentration levels (limit of quantification, 40, 100, and 400 ng/L) were 62.6–100.9%, with intra-day and inter-day relative standard deviations below 12.6%. The limit of detection and limit of quantification were 1.0–15.0 ng/L and 3.0–40.0 ng/L, respectively. Finally, the proposed method was successfully applied to the analysis of real water samples.

Freeze-thaw approach: A practical sample preparation strategy for residue analysis of multi-class veterinary drugs in chicken muscle

Seven drugs from different classes, namely, fluoroquinolones (enrofloxacin, ciprofloxacin, sarafloxacin), sulfonamides (sulfadimidine, sulfamonomethoxine), and macrolides (tilmicosin, tylosin), were used as test compounds in chickens by oral administration, a simple extraction step after cryogenic freezing might allow the effective extraction of multi-class veterinary drug residues from minced chicken muscles by mix vortexing. On basis of the optimized freeze-thaw approach, a convenient, selective, and reproducible liquid chromatography with tandem mass spectrometry method was developed. At three spiking levels in blank chicken and medicated chicken muscles, average recoveries of the analytes were in the range of 71-106 and 63-119%, respectively. All the relative standard deviations were <20%. The limits of quantification of analytes were 0.2-5.0 ng/g. Regardless of the chicken levels, there were no significant differences (P > 0.05) in the average contents of almost any of the analytes in medicated chickens between this method and specific methods in the literature for the determination of specific analytes. Finally, the developed method was successfully extended to the monitoring of residues of 55 common veterinary drugs in food animal muscles.

Development and Validation of a Multiclass, Multiresidue Method for Veterinary Drug Analysis in Infant Formula and Related Ingredients Using UHPLC-MS/MS

A multiclass, multiresidue method based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) has been developed and validated for the analysis of around 150 veterinary drugs in infant formula and related dairy ingredients. The included analytes belong to the following veterinary drug classes: anthelmintics, antibiotics (aminoglycoside, amphenicols, β-lactams-penicillins and cephalosporins, lincosamides, macrolides, quinolones, sulfonamides, tetracyclines, and others), antimicrobial growth promoters, antiprotozoals, β-agonists, coccidiostats, dyes, pesticides, and tranquilizers. The sample preparation procedure involves dispersing the sample in 0.05 M EDTA solution in water, followed by extraction with 0.1% formic acid in acetonitrile, drying down an aliquot of the extract, and reconstituting it in a water-acetonitrile mixture. The analyte detection, identification, and quantitation are performed by UHPLC-MS/MS using positive electrospray ionization mode. The method was validated in infant formula powder, whole milk powder, and whey protein isolate, typically achieving limits of quantitation (meeting acceptable recovery and precision validation criteria) at 1-10 ng/g.