Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, Brno CZ-60200, Czech Republic.
Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, Brno CZ-60200, Czech Republic.
J Chromatogr A. 2023 Nov 22;1711:464455. doi: 10.1016/j.chroma.2023.464455. Epub 2023 Oct 17.
Three penicillin-based β-lactam antibiotics (benzylpenicillin, amoxicillin, and ampicillin) were extracted by electromembrane extraction (EME) and determined in the resulting extracts by capillary zone electrophoresis (CZE) with UV-Vis detection. The EME was optimized for the simultaneous clean-up of complex samples and preconcentration of the three antibiotics and employed 1-octanol as the organic phase interface (impregnated in the pores of a hollow fiber), acidified donor solution (pH 3), and phosphate buffer (pH 5.6) as the acceptor solution. The EMEs were carried out for 20 min at 300 V and constant stirring (750 rpm) of the donor solution. At the optimized EME-CZE conditions, the sensitivity of the analytical method was sufficient for the determination of the three β-lactam antibiotics in undiluted cow's milk at concentrations below the EU maximum residue limits (4 μg/L) in foodstuffs. The method was simple, rapid, and convenient and offered extraction recoveries of 13.5 - 87.3 %, enrichment factors of 23.6 - 152.8, repeatability (RSD values) better than 7.6 %, linear analytical response in the 1 - 100 μg/L (3 - 100 μg/L for benzylpenicillin) concentration range with correlation coefficients ≥ 0.9997, and limits of detection from 0.2 to 1.2 μg/L. The proposed analytical concept was used for the rapid control of milk quality (i.e. assessment of excessive use of antibiotics in dairy animals), moreover, it was further extended to the trace determination of β-lactam antibiotics in other complex samples, such as in wastewater.
三种基于青霉素的β-内酰胺抗生素（苄青霉素、阿莫西林和氨苄青霉素）通过电膜萃取（EME）提取，并通过毛细管区带电泳（CZE）与紫外可见检测在所得提取物中进行测定。EME 经过优化，可同时对复杂样品进行净化和三种抗生素的预浓缩，并采用 1-辛醇作为有机相界面（浸渍在中空纤维的孔中）、酸化供体溶液（pH 3）和磷酸盐缓冲液（pH 5.6）作为接受溶液。在 300 V 和供体溶液恒定搅拌（750 rpm）下进行 20 分钟 EME。在优化的 EME-CZE 条件下，该分析方法的灵敏度足以在未经稀释的牛奶中检测到三种β-内酰胺抗生素，浓度低于食品中欧盟最大残留限量（4μg/L）。该方法简单、快速、方便，萃取回收率为 13.5-87.3%，富集因子为 23.6-152.8，重复性（RSD 值）优于 7.6%，在 1-100μg/L（3-100μg/L 用于苄青霉素）浓度范围内具有线性分析响应，相关系数≥0.9997，检测限为 0.2-1.2μg/L。所提出的分析概念用于快速控制牛奶质量（即评估奶牛中抗生素的过度使用），此外，它还进一步扩展到其他复杂样品（如废水）中β-内酰胺抗生素的痕量测定。
