离子液体萃取分光光度法测定水中四环素类抗生素

以疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐(Bmim]PF6)替代挥发性有机溶剂萃取分离水中的四环素类抗生素,在pH值为6.5时,金属离子Al(Ⅲ)能与四环素类抗生素(TCs)形成稳定的配合物,Bmim]PF6能够高效萃取该配合物,可用光度法直接测定,最大吸收波长为380 nm,方法灵敏度高,TCs-Al(Ⅲ)配合物摩尔吸光系数达到1.38×106 L/(mol.cm),一次萃取率达97.2%,分配系数达到174。实测某鱼塘水样,加标回收率在81.25%～93.66%之间,RSD≤4.25%,该方法可用于环境水样中四环素类抗生素残留的分析,简便、快速、无毒、无污染。

Determination of Tetracycline Antibiotics by Ionic Liquid Extraction and Spectrophotometry

As a substitute of traditional volatile organic solvent, the hydrophobic ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (Bmim] PF_6) was used to extract tetracyclines antibiot-ics (TCs). Aluminum ion and TCs form a stable complex at pH 6.5, and Bmim] PF_6 can extract the complex effectively. In the ionic liquid phase, the complex has high absorbance with the maximum wave of 380 nm, the apparent molar absorptivity is 1.38×10~6L/(mol·cm), the extraction yield can reach over 97.2% by one stage extraction, and the partition coefficient is 174. In actual determination of TCs in fish pond water sample, the recovery with standard addition is between 81.25% and 93.66%, and the relative standard deviation is equal to or less than 4.25%. This method is suitable for determining the trace TCs residue in water sample with the merits, such as simple and fast operation, non toxicity and non pollution.