Positional isomers of alkenes are frequently transparent to the mass spectrometer and it is difficult to provide convincing data to support their presence. This work focuses on the development of a new reactive nano-electrospray ionization (nESI) platform that utilizes non-inert metal electrodes (e.g., Ir and Ru) for rapid detection of fatty acids by mass spectrometry (MS), with concomitant localization of the CC bond to differentiate fatty acid isomers. During the electrospray process, the electrical energy (direct current voltage) is harnessed for in situ oxide formation on the electrode surface via electro-oxidation. The as-formed surface oxides are found to facilitate in situ epoxide formation at the CC bond position and the products are analyzed by MS in real-time. This phenomenon has been applied to analyze isomers of unsaturated fatty acids from complex serum samples, without pre-treatment.

中文翻译：

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集成的电催化nESI-MS平台，可直接从未经处理的生物流体中定量分析脂肪酸异构体

烯烃的位置异构体通常对质谱仪是透明的，并且很难提供令人信服的数据来支持它们的存在。这项工作的重点是开发新的反应性纳米电喷雾电离（nESI）平台，该平台利用非惰性金属电极（例如Ir和Ru）通过质谱（MS）快速检测脂肪酸，并同时定位C C键可区分脂肪酸异构体。在电喷雾过程中，利用电能（直流电压）通过电氧化在电极表面上原位形成氧化物。发现形成的表面氧化物有助于在C温度下原位形成环氧化物MS实时分析C键位置和产物。这种现象已应用于分析复杂血清样品中不饱和脂肪酸的异构体，而无需进行预处理。