A novel portable Raman scattering platform for antibiotic screening in pig urine

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Chemometrics

Background:

• Global attention on food safety necessitates early detection of antibiotic residues in meat.
• Conventional methods for detecting antibiotic residues are post-slaughter, leading to significant economic losses.
• Developing rapid, on-farm screening methods is crucial for preventing business losses and ensuring consumer health.

Purpose of the Study:

• To develop and validate a portable surface-enhanced Raman spectroscopy (SERS) method.
• To utilize multivariate curve resolution-alternation least squares (MCR-ALS) for quantitative analysis of antibiotic residues.
• To determine the concentrations of enrofloxacin, oxytetracycline, and neomycin in pig urine, aiming for cost and time efficiency.

Main Methods:

• Preparation of standard antibiotic solutions (enrofloxacin, oxytetracycline, neomycin) in aqueous media.
• Determination of limit of detection (LOD) for each antibiotic using SERS.
• Analysis of enrofloxacin in spiked pig urine samples and in urine collected post-administration using SERS and MCR-ALS.

Main Results:

• Achieved LODs of 0.5 ppm for enrofloxacin, 2.0 ppm for oxytetracycline, and 100 ppm for neomycin in aqueous solutions.
• Successfully detected spiked enrofloxacin in pig urine at concentrations of 10, 20, 50, 100, and 10,000 ppm, with an LOD of 10 ppm.
• Validated the technique using pig urine samples, showing higher enrofloxacin concentrations on day 7 compared to day 1 due to continuous administration, correlating with circulation time and metabolism.

Conclusions:

• The combination of SERS and MCR-ALS is a promising technique for on-farm screening of antibiotic residues in pig urine.
• This approach offers increased efficiency, reduced costs, and shorter analysis times compared to conventional methods.
• Further optimization of the Raman dataset may be required for enhanced sensitivity tailored to individual farm needs.