Oxytetracycline, tetracycline, chlortetracycline and doxycycline in pasteurised cow’s milk commercialised in Brazil

The aim of this study was to investigate the presence of tetracycline residues in pasteurised cow’s milk using high-performance liquid chromatography coupled with UV/VIS detection to determine the exposure of Brazilian’s population to antibiotic residues. One hundred samples collected from the State of Paraná, Brazil, were analysed. Three of these samples were contaminated at the following concentrations: 121.8 µg·kg−1 for oxytetracycline, 93.5 µg·kg−1 for tetracycline and 134.6 µg·kg−1 for chlortetracycline (61.6 µg·kg−1) and doxycycline (73.0 µg·kg−1). The median tetracycline residue concentration found in the samples was 42.3 µg·kg−1, and the estimated daily intake (EDI) was 0.05 µg Kg−1 bw day−1 in Brazil. These results demonstrate that the occurrence of tetracycline in Brazilian milk was low (3%) and only for 2% above the maximum residue limit, so the risk to the population from the presence of these residues in milk was low (<1% of the acceptable daily intake).

本研究旨在采用紫外-可见光检测器联用高效液相色谱法（High Performance Liquid Chromatography, HPLC），检测巴氏杀菌牛乳中的四环素类残留，以评估巴西人群对抗生素残留的暴露水平。本研究共分析了采自巴西巴拉那州的100份牛乳样本。其中3份样本检出四环素类残留，各成分浓度如下：土霉素（oxytetracycline）121.8 μg·kg⁻¹、四环素（tetracycline）93.5 μg·kg⁻¹，金霉素（chlortetracycline）与多西环素（doxycycline）的浓度分别为61.6 μg·kg⁻¹与73.0 μg·kg⁻¹，二者总浓度为134.6 μg·kg⁻¹。所有样本中四环素类残留的中位数浓度为42.3 μg·kg⁻¹，巴西人群的估计每日摄入量（Estimated Daily Intake, EDI）为0.05 μg·kg⁻¹ 体重·天⁻¹。本研究结果显示，巴西市售巴氏杀菌牛乳中四环素类残留的检出率为3%，仅2%的样本残留量超过最大残留限量（Maximum Residue Limit, MRL）标准，因此牛乳中此类残留对人群的健康风险极低，仅为每日允许摄入量（Acceptable Daily Intake, ADI）的1%以下。