Abstract：
This work presents the development, synthesis, and application of a layered double hydroxide (LDH) coupled to magnetic particles for the removal of antibiotics as tetracyclines (TC´s): tetracycline (TC), chlortetracycline (CT), oxytetracycline (OT), and doxycycline (DT) from milk samples. The LDH synthesis conditions, reaction time (30-90 min), molar ratios Mg2+/Al3+ (7:1-1:7), interlayer anion (NO3-, Cl-, CO32-, and dodecyl sulphate (DS-)) were evaluated. Under synthesis conditions (reaction time of 30 min, Mg2+/Al3+ molar ratio of 7:1, and DS- as interlayer anion), the LDH was coupled in a magnetic solid phase microextraction (MSPμE) methodology. At the optimal extraction conditions (pH 6, 5 min of contact time, 10 mg of adsorbent), a removal percentage of 99.0 % was obtained for each tetracycline. FTIR, TGA, SEM, and adsorption isotherms were employed to characterize the optimal adsorbent. Each experiment was corroborated by large-volume sample stacking capillary electrophoresis (LVSS-CE). The adsorbent was applied directly to positive milk samples (previously tested) for TC´s removal.
摘要：
这项工作提出了发展，合成，以及与磁性颗粒偶联的层状双氢氧化物（LDH）的应用，用于去除抗生素如四环素（TC）：四环素（TC），金霉素（CT），土霉素（OT），和来自牛奶样品的强力霉素(DT)。LDH的合成条件,反应时间（30-90分钟），摩尔比Mg2+/Al3+(7:1-1:7)，层间阴离子(NO3-，Cl-,CO32-,和十二烷基硫酸盐(DS-)进行评价。在合成条件下（反应时间为30min，Mg2+/Al3+摩尔比为7:1，DS-作为层间阴离子），LDH采用磁性固相微萃取（MSPμE）方法进行偶联。在最佳提取条件(pH6，接触时间5min，10毫克吸附剂)，每种四环素的去除率为99.0%。FTIR,TGA,SEM,和吸附等温线用于表征最佳吸附剂。每个实验都通过大体积样品堆叠毛细管电泳（LVSS-CE）进行证实。将吸附剂直接应用于阳性乳样品(先前测试的)以去除TC。
