This research presents a simple and green in situ solid phase extraction (is-SPE) combined with high-performance liquid chromatography (HPLC) for the simultaneous analysis of tetracyclines (TCs) including tetracycline, oxytetracycline, and chlortetracycline. In is-SPE, TCs were efficiently extracted through the precipitation formation of dissolvable layered double hydroxides (LDHs) by mixing the LDH components such as magnesium and aluminum ions (both in metal chloride salts) thoroughly in an alkaline sample solution. After the centrifugation, the precipitate was completely dissolved with trifluoroacetic acid to release the enriched TCs, and then analyzed by HPLC. Under optimized conditions, this method gave good enrichment factors (EFs) of 41–93 with low limits of detection (LODs) of 0.7–6 μg/L and limits of quantitation (LOQs) of 3–15 μg/L. Also, the proposed method was successfully applied for the determination of TCs in water and milk samples with the recoveries ranging from 81.7-108.1% for water and 55.7-88.7% for milk.

这项研究提出了一种简单，绿色的原位固相萃取（is -SPE）与高效液相色谱（HPLC）相结合的方法，可同时分析四环素（TC），包括四环素，土霉素和金霉素。在是-SPE通过将可溶解的层状双氢氧化物（LDHs）沉淀形成而有效地提取TC，方法是将LDH组分（例如镁和铝离子（均在金属氯化物盐中））充分混合在碱性样品溶液中。离心后，沉淀物用三氟乙酸完全溶解以释放出富集的TC，然后通过HPLC分析。在优化的条件下，该方法可得到良好的富集因子（EFs）为41–93，检测限（LOD）为0.7–6μg/ L，定量限（LOQs）为3–15μg/ L。而且，该方法成功地用于水和牛奶样品中TC的测定，水的回收率在81.7-108.1％之间，牛奶的回收率在55.7-88.7％之间。