Wang Huili, Gao Ming, Gao Jiajia, Yu Nana, Huang Hong, Yu Qing, Wang Xuedong
College of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China.
College of Marine Life, Ocean University of China, Qingdao, Shandong, 266000, China.
Anal Bioanal Chem. 2016 Sep;408(22):6105-14. doi: 10.1007/s00216-016-9719-1. Epub 2016 Jun 25.
In conventional microextraction procedures, the disperser (organic solvent or ionic liquid) is left in the aqueous phase and discarded after finishing the microextraction process. Because the disperser is water-soluble, it results in low extraction recovery for polar compounds. In this investigation, an ionic-liquid-based microextraction (ILBME) was integrated with salting-out assisted liquid-liquid microextraction (SALLME) to build an ionic-liquid-based, salt-induced, dual microextraction (ILSDME) for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P, -1.0 to 1.0). The proposed ILSDME method incorporates a dual microextraction by converting the disperser in the ILBME to the extractor in the SALLME. Optimization of key factors was conducted by integrating single-factor experiments and central composite design. The optimized experimental parameters were 80 μL [C8MIM][PF6] as extractor, 505 μL acetone as disperser, pH = 2.0, 4.1 min extraction time, and 4.2 g of Na2SO4. Under optimized conditions, high ERs (90.6-103.2 %) and low LODs (0.07-0.61 μg kg(-1)) were determined for five FQs in swine feed. Experimental precision based on RSDs was 1.4-5.2 % for intra-day and 2.4-6.9 % for inter-day analyses. The combination of ILBME with SALLME increased FQ recoveries by 15-20 % as compared with SALLME, demonstrating that the ILSDME method can enhance extraction efficiency for polar compounds compared to single-step microextraction. Therefore, the ILSDME method developed in this study has wide application for pretreatment of moderately to highly polar pollutants in complex matrices. Graphical Abstract A dual microextraction was developed by integrating ionic-liquid-based microextraction with salting-out assisted liquid-liquid microextraction for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P = -1.0 to 1.0). The principle of dual microextraction is based on converting the remaining disperser from the first microextraction into an extractor in the second microextraction. Single-factor experiment and central composite design were applied for optimizing operational parameters using 3D response surfaces and contour lines. Under optimized conditions, the method provided high extraction recoveries and low LODs for five FQs in swine feed. The prominent advantage of the dual microextraction is rapid and highly efficient extraction of moderately to highly polar fluoroquinolones from complex matrices.
在传统的微萃取方法中，分散剂（有机溶剂或离子液体）留在水相中，并在微萃取过程完成后被弃去。由于分散剂是水溶性的，因此对于极性化合物而言，其萃取回收率较低。在本研究中，基于离子液体的微萃取（ILBME）与盐析辅助液液微萃取（SALLME）相结合，构建了一种基于离子液体的、盐诱导的双微萃取（ILSDME）方法，用于分离五种高极性（log P，-1.0至1.0）的氟喹诺酮类抗生素（FQs）。所提出的ILSDME方法通过将ILBME中的分散剂转化为SALLME中的萃取剂，实现了双微萃取。通过单因素实验和中心复合设计对关键因素进行了优化。优化后的实验参数为：80 μL [C8MIM][PF6]作为萃取剂，505 μL丙酮作为分散剂，pH = 2.0，萃取时间4.1分钟，以及4.2 g Na2SO4。在优化条件下，测定了猪饲料中五种FQs的高萃取回收率（90.6 - 103.2%）和低检测限（0.07 - 0.61 μg kg⁻¹）。基于相对标准偏差（RSDs）的实验精密度，日内为1.4 - 5.2%，日间为2.4 - 6.9%。与SALLME相比，ILBME与SALLME的结合使FQs的回收率提高了15 - 20%，这表明与单步微萃取相比，ILSDME方法可以提高极性化合物的萃取效率。因此，本研究开发的ILSDME方法在复杂基质中对中度至高度极性污染物的预处理方面具有广泛的应用。图形摘要 通过将基于离子液体的微萃取与盐析辅助液液微萃取相结合，开发了一种双微萃取方法，用于分离五种高极性（log P = -1.0至1.0）的氟喹诺酮类抗生素（FQs）。双微萃取的原理是基于将第一次微萃取中剩余的分散剂转化为第二次微萃取中的萃取剂。采用单因素实验和中心复合设计，利用三维响应面和等高线对操作参数进行优化。在优化条件下，该方法为猪饲料中的五种FQs提供了高萃取回收率和低检测限。双微萃取的突出优点是能够从复杂基质中快速、高效地萃取中度至高度极性的氟喹诺酮类化合物。
