【摘要】 强力霉素(DC)是四环素类抗生素(TCs)的一种，因其广谱高效而被广泛应用，但其代谢性能差，进入环境蓄积对人体和动植物的健康存在威胁；因此，开发一种简单、快速、成本低且灵敏度高的检测水环境和食品环境中DC残留的检测方法具有十分重要的意义。本研究利用非离子型表面活性剂曲拉通X-100(Triton X-100)和钙离子对DC荧光协同增敏效应，建立一种简单、快速测定牛奶和水环境中DC的荧光分析技术。在碱性环境中，DC属于弱荧光物质，但与Triton X-100和钙离子共存时，由于Triton X-100和钙离子对DC的胶束增溶和络合反应所引起的荧光增敏效果，DC的荧光会显著增强。结果表明，在最优的检测体系中，该检测方法对DC的浓度在0.005～1.000μmol/L范围内表现出良好的线性关系，其线性方程式为y=2.940 8x+0.080 7,决定系数R~2为0.994 1,检测限(S/N=3)和定量限(S/N=10)分别为0.8和66.8 nmol/L。在诸多干扰抗生素中，该检测方法对DC表现出很高的选择性。实际牛奶和水样中的DC回收率为80.0%～119.6%,相对标准偏差为2.29%～9.33%,说明该检测方法在实际水和食品环境中的准确性和可信度较高。因此，Triton X-100和金属钙离子对DC的协同荧光增敏技术可以选择性检出DC,为水和食品环境中TCs监测提供了一种新的思路。更多还原

【Abstract】 Doxycycline(DC), a type of tetracycline antibiotic(TC), is widely used in disease treatment and animal husbandry because of its broad-spectrum and high efficiency. However, due to its poor metabolization, the accumulation of DC in the environment poses a threat to human health, animals and plants. Therefore, it is of great importance to develop a simple, rapid, low-cost and sensitive assay for the detection of DC residues in water and food environments. In this study, a simple and rapid fluorescence analytical method for the determination of DC in milk and aqueous environments was developed utilizing the synergistic sensitizing effect of the nonionic surfactant Triton X-100 and the metal calcium ions on DC fluorescence. In an alkaline environment, DC is a weakly fluorescent substance and gives a green fluorescence intensity at 520 nm upon excitation at 360 nm. When DC coexisted with Triton X-100, the micellar environment of Triton X-100 enhanced the fluorescence of DC at 520 nm to a certain extent, but there was no significant change under the UV lamp. In the presence of calcium ions, the hydroxyl and ketone groups on the DC structure formed stable complexes with metal ions, and the fluorescence was slightly enhanced at 520 nm, emitting green fluorescence under the UV lamp. However, when Triton X-100 coexisted with calcium ions, through the complexation and sensitization of calcium ions to DC, and the micellar solubilization and sensitization of Triton X-100 to the complex of DC reacting with calcium ions, the fluorescence of DC was greatly enhanced at 520 nm, emitting bright green fluorescence. Under the optimal detection conditions, the results showed that the analytical method exhibited good linearity in the range of 0.005-1.000 μmol/L for the DC concentrations, with a linear equation of y=2.940 8x+0.080 7(R~2=0.994 1). Limit of detection(S/N=3) and limit of quantification(S/N=10) were obtained 0.8 and 66.8 nmol/L, respectively, which are far lower than those maximum residue limits(MRLs) in food environment of China. Among the many interfering antibiotics, the analytical method showed high selectivity for DC. The recoveries of DC in spiked real milk and water samples ranged from 80.0% to 119.6% with the relative standard deviations(RSD) of 2.29%-9.33%, which indicated that the analytical method had good accuracy and confidence in real water and food environments. Therefore, the synergistic fluorescence sensitization of DCs by Triton X-100 and cation calcium ions could apply to detect DC sensitively and selectively, providing a new idea for the monitoring of TCs in water and food environments.更多还原