Development of a Quantitative Multi-Class Method for 18 Antibiotics in Chicken, Pig, and Fish Muscle using UPLC-MS/MS

A unique implementation of Hantzsch reaction for determination of natamycin in Yoghurt: Hyphenated with Box-Behnken-design for optimization

This study aims to develop a novel and selective method for the detection of natamycin (E235) in yoghurt. The suggested method adopts an application of Hantzsch reaction to turn on the fluorescence behavior of natamycin (blue fluorescence), allowing its sensitive and selective determination in yoghurt samples without any overlapping at 485 nm. The originality of the research lies in the fact that this application takes place for the first time, also the detection (LOD) and quantification (LOQ) limits were very low (0.02 and 0.06μg mL-1, respectively) with a linear concentration range of 0.1-1.0 μgmL-1. Moreover, the developed method was employed for the detection of E235 in yoghurt sample with a good recoveries (98.80 ± 1.20-99.20 ± 1.15 (%), over a concentration range of 0.5-1.0 μgmL-1, (LOD = 0.04 and LOQ = 0.12 μgmL-1). Furthermore, the specificity and convenient application of our intended method is an attempt to determine E235 in milk anddairy products with easily followable steps.

Detection of Antibiotic Residues in Blossom Honeys from Different Regions in Turkey by LC-MS/MS Method

In the present study, a total of 80 commercial blossom honey samples were obtained from local markets in Ankara, Turkey. These honeys were analyzed for 35 important and risky antibiotics (sulfonamide, tetracycline, macrolide, cephalosporin, aminoglycoside, quinolone, nitrofuran, chloramphenicol, and anthelmintic groups) by the LC-MS/MS multi-antibiotic method. In addition to these analyses, pH measure, moisture, and electrical conductivity were determined in these honey samples. Finally, seven out of 35 antibiotic residues investigated in the honeys were positive. The most frequently detected antibiotics in the analyzed samples were dihydrostreptomycin, streptomycin, erythromycin, sulfadimidine (sulfamethazine), and enrofloxacin as 58.75%, 22.5%, 13.75%, 10%, and 2.5%, respectively. Tetracycline and doxycycline were detected in only one sample. The pH, moisture, and electrical conductivity values of the honey samples were determined as between pH 3.78 and 5.41, 17.48 and 18.03%, and 0.25 and 0.47 mS/cm, respectively. In terms of food safety and human health, it is very important to monitor the residues of these pharmacologically active substances with analytical methods.

Determination of Antibiotic Residues in Aquaculture Products by Liquid Chromatography Tandem Mass Spectrometry: Recent Trends and Developments from 2010 to 2020

The issue of antibiotic residues in aquaculture products has aroused much concern over the last decade. The residues can remain in food and enter the human body through the food chain, posing great risks to public health. For the safety of foods and products, many countries have issued maximum residue limits and banned lists for antibiotics in aquaculture products. Liquid chromatography tandem mass spectrometry (LC/MS/MS) has been widely used for the determination of trace antibiotic residues due to its high sensitivity, selectivity and throughput. However, considering its matrix effects during quantitative measurements, it has high requirements for sample pre-treatment, instrument parameters and quantitative method. This review summarized the application of LC/MS/MS in the detection of antibiotic residues in aquaculture products in the past decade (from 2010 to 2020), including sample pre-treatment techniques such as hydrolysis, derivatization, extraction and purification, mass spectrometry techniques such as triple quadrupole mass spectrometry and high-resolution mass spectrometry as well as status of matrix certified reference materials (CRMs) and matrix effect.

Development of a monoclonal-based ic-ELISA for the determination of kitasamycin in animal tissues and simulation studying its molecular recognition mechanism

To monitor the residue of kitasamycin (KIT), a monoclonal antibody against KIT was prepared, and a 50% inhibition concentration (IC₅₀) of 5.7 ± 1.4 μg/L was achieved with the most sensitive antibody, KA/2A9, by optimizing ELISA conditions. The LODs for KIT in different animal tissues ranged from 22.47 μg/kg to 29.32 μg/kg, and the recoveries of the fortified tissues were 70% ~ 120% with coefficients of variation below 20%. Then, KIT-specific scFv KA/2A9/3 was prepared for the first time. Homologous modeling and molecular docking results indicated that the key amino acids of KA/2A9/3 scFv are TYR-92 (CDRL3), SER-93 (CDRL3), ASP-155 (CDRH1) and GLY-226 (CDRH3), and the hydrogen bond is the main force. And then, virtual mutation provides a method to evolve KA/2A9/3 scFv antibodies. These results contribute to comprehending the antigen-antibody binding mechanism and provide effective information for in vitro affinity maturation of anti-KIT scFv.

Antibiotic Residues in Food: Extraction, Analysis, and Human Health Concerns

The abundant use of antibiotics leads to antibiotic residues in frequently consumed foods. Residual antibiotics in food may have adverse effects on humans by directly causing disease via low-dose exposure and indirect harm via antibiotic resistance. However, the current methods for antibiotic extraction and analysis in food have not yet formed a uniform standard, and only a few data exist regarding the residual antibiotic condition in various types of foods. Hence, we review the literature since 2008 to summarize analytical methods and residue status of antibiotics in food. Then, we discuss the causes of antibiotic residues in food and the possible hazards to human health. We hope that the joint efforts of the scientific community and political circles will lead to the formation of a unified standard for the extraction and analysis of antibiotics in food, to allow for comprehensive monitoring of residual antibiotics and ensure human health.