Liu Yikun, Zhou Wei, Sun Wenqi, Chen Zilin
Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, and Wuhan University School of Pharmaceutical Sciences, Wuhan, 430071, China; State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing, 10080, China.
Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, and Wuhan University School of Pharmaceutical Sciences, Wuhan, 430071, China.
J Chromatogr A. 2021 May 24;1645:462123. doi: 10.1016/j.chroma.2021.462123. Epub 2021 Apr 1.
Micellar electrokinetic chromatography (MEKC) is a good separation technique with high efficiency, high selectivity and simple preparation process. Hyphenation of MEKC with mass spectrometry (MS) could extend its application in complex sample analysis. However, direct coupling MEKC using commonly used surfactants like sodium dodecyl sulfate (SDS) with ESI-MS will lead to strong signal suppression. In this work, a MEKC-MS method using volatile ammonium perfluorooctanoate as surfactant was developed. The MS compatibility of ammonium perfluorooctanoate was investigated. The result revealed that there is no signal suppression even the concentration of ammonium perfluorooctanoate was up to 300 mM. Meanwhile, we found that ammonium perfluorooctanoate used as surfactant in MEKC provided powerful F-F interaction and hydrophobic interaction, which was beneficial for separation of fluorinated compounds. Using the ammonium perfluorooctanoate based MEKC method, several groups of fluorinated compounds, which cannot be separated using non-fluorinated surfactants like lauric acid and SDS based MEKC method, were baseline separated. Finally, the MEKC-ESI-MS method was successfully applied for analysis of two herbicides including fluometuron and fenuron in lake water samples with high separation efficiency, high sensitivity, good linearity and reproducibility.
胶束电动色谱法（MEKC）是一种高效、高选择性且制备过程简单的良好分离技术。MEKC与质谱联用（MS）可扩展其在复杂样品分析中的应用。然而，使用十二烷基硫酸钠（SDS）等常用表面活性剂将MEKC直接与电喷雾电离质谱（ESI-MS）联用会导致强烈的信号抑制。在本研究中，开发了一种使用全氟辛酸铵作为表面活性剂的MEKC-MS方法。研究了全氟辛酸铵的质谱兼容性。结果表明，即使全氟辛酸铵的浓度高达300 mM，也不存在信号抑制。同时，我们发现全氟辛酸铵在MEKC中用作表面活性剂时提供了强大的氟-氟相互作用和疏水相互作用，这有利于含氟化合物的分离。使用基于全氟辛酸铵的MEKC方法，几组使用月桂酸和基于SDS的MEKC方法无法分离的含氟化合物实现了基线分离。最后，MEKC-ESI-MS方法成功应用于湖水样品中伏草隆和非草隆两种除草剂的分析，具有分离效率高、灵敏度高、线性良好和重现性好的特点。
