Detection of azithromycin residue in broiler feathers by liquid chromatography-tandem mass spectrometry

Evaluating antibiotic occurrence, degradation, and environmental risks in poultry litter within Argentina's agricultural hub

This study explores the relationship between poultry farming's antibiotic administration practices and residual antibiotic levels in the litter before its application onto agricultural soils. Twenty-three antibiotics were performed across 19 Argentinean farms representing diverse antibiotic management practices. Analysis revealed up to 20 antibiotics from eight chemical classes in poultry litter samples, with tylosin, enrofloxacin, and salinomycin being the most relevant drugs. Farms with restricted antibiotic use in feed exhibited lower residual concentrations. A self-heating treatment was tested to reduce litter antibiotic levels. Although a 60 % reduction of antibiotics was found after treatment, prevalent compounds persisted at residual levels. Regulatory measures and comprehensive litter treatments pre-application are crucial to mitigate environmental risks. This is the first study that provides insight on the occurrence of >20 drugs in real poultry production scenarios from Latin America and demonstrates how relatively simple treatments can be readily applied to decrease the associated environmental risks.

Impregnation of biochar with montmorillonite and its activation for the removal of azithromycin from aqueous media

An inexpensive and environmentally friendly composite synthesized from rice husk, impregnated with montmorillonite and activated by carbon dioxide, was investigated for the removal of azithromycin from an aqueous solution. Various techniques were used to characterize adsorbents in detail. The sorption process was primarily regulated by the solution pH, pollutant concentration, contact duration, adsorbent dose, and solution temperature. The equilibrium data were best analyzed using the nonlinear Langmuir and Sips (R² > 0.97) isotherms, which revealed that adsorption occurs in a homogenous manner. The adsorption capacity of pristine biochar and carbon dioxide activated biochar-montmorillonite composite was 33.4 mg g^-1 and 44.73 mg g^-1, respectively. Kinetic studies identified that the experimental data obeyed the pseudo-second-order and Elovich models (R² > 0.98) indicating the chemisorption nature of adsorbents. The thermodynamic parameters determined the endothermic and spontaneous nature of the reaction. The ion exchange, π-π electron-donor-acceptor (EDA) interactions, hydrogen-bonding, and electrostatic interactions were the plausible mechanisms responsible for the adsorption process. This study revealed that a carbon dioxide activated biochar-montmorillonite composite may be used as an effective, sustainable, and economical adsorbent for the removal of azithromycin from polluted water.

Solvothermal synthesis of nitrogen-doped carbon quantum dots for the sensitive detection of azithromycin

Carbon quantum dots are widely used in various drug detection applications because of their excellent photoluminescence properties. However, there are few reports about the detection of macrolide antibiotics. In this work, blue emitting nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by using a hydrothermal method, which exhibit the most prominent emission band at 464 nm at an excitation wavelength of 414 nm. And it was found that Cu²⁺alone or the macrolide antibiotic azithromycin had no significant effect on the fluorescence intensity of N-CQDs. Still, when the two were mixed, they quenched the fluorescence of N-CQDs. Based on this, a fluorescence assay for azithromycin were developed. The fluorescence of the mixture of N-CQDs and Cu²⁺showed good linearity with azithromycin (0.52-42.2μM) with a low detection limit of 0.52μM.

Determining a wide range of antibiotics and pesticides in poultry feathers using selective accelerated solvent extraction-liquid chromatography-mass spectrometry

This study established a detection method based on accelerated solvent extraction-liquid chromatography-mass spectrometry for determining residues of 3 chloramphenicols, 8 macrolides, 18 sulfonamides, 4 nitroimidazoles, 15 insecticides, and 22 fungicides in poultry feathers. The extraction solvent, methanol, was used for a static extraction time of 5 min, and repeated three times. Fifty milligrams of adsorbents C18/PSA (1 : 1, W/W) were added to the extraction cell to achieve simultaneous extraction and purification. The extraction efficiency of three solvents, methanol, acetonitrile and ethyl acetate, was investigated. An orthogonal experimental design was used to explore the optimal combination of extraction temperature, static extraction time, number of extraction cycles, and adsorbent ratio for accelerated solvent extraction. After the optimal ratio was determined, the dosage of adsorbents was optimized. The extracted sample solution was concentrated by blowing nitrogen, redissolved, passed through a 0.22 μm PTFE membrane filter, then injected for instrumental analysis. The validation results showed that the recovery of the proposed method was 60.4-107.6%, the limit of detection 0.2-3.0 μg kg^-1, and the limit of quantification 0.5-8.3 μg kg^-1. This quantitative multi-residue detection method was able to determine the residues of 70 target compounds in poultry feathers.