Antibiotic residues in pasteurised and Raw Cow’s milk in Dhaka, Bangladesh

ABSTRACT

This study aimed to investigate antibiotic residues such as oxytetracycline, ciprofloxacin, enrofloxacin and levofloxacin, in both pasteurised and raw cow’s milk. A method using high-performance liquid chromatography with a UV detector (HPLC-UV) was developed and validated following International Conference on Harmonization (ICH) guidelines for simultaneous detection and quantification of these residues. The technique demonstrated linearity, with r² values ranging from 0.999 to 1.00 within the 1.3–15.0 μg ml⁻¹ range for each antibiotic. Thirty cow’s milk samples, raw and pasteurised, from Dhaka’s local markets were analysed, revealing the presence of enrofloxacin and levofloxacin, while oxytetracycline was absent in all samples. Notably, pasteurised milk samples contained enrofloxacin, levofloxacin and oxytetracycline, with groups P6 and P7 exceeding the Maximum Residue Limit for enrofloxacin, levofloxacin and ciprofloxacin (121 µg l⁻¹). This study emphasises antibiotic residues in milk, with a validated method holding promise for routine analysis in industries requiring simultaneous quantitation of multiple antibiotics.

KEYWORDS:

• Antibiotic residues
• pasteurized and Raw Cow’s milk
• milk contamination
• food safety
• quantification
• HPLC-UV

Acknowledgments

Prof. ABM Faroqe thanks BANBEIS (Bangladesh Bureau of Educational Information and Statistics), Dhaka, Bangladesh, for research support. We also acknowledge Abdur Rahim (Senior Scientific Officer, BCSIR) for providing support with Grammarly Premium edition software during manuscript editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.