Cox Jonathan T, Marginean Ioan, Kelly Ryan T, Smith Richard D, Tang Keqi
Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
J Am Soc Mass Spectrom. 2014 Dec;25(12):2028-37. doi: 10.1007/s13361-014-0856-5. Epub 2014 Mar 28.
Arrays of chemically etched emitters with individualized sheath gas capillaries were developed to enhance electrospray ionization (ESI) efficiency at subambient pressures. By incorporating the new emitter array in a subambient pressure ionization with nanoelectrospray (SPIN) source, both ionization efficiency and ion transmission efficiency were significantly increased, providing enhanced sensitivity in mass spectrometric analyses. The SPIN source eliminates the major ion losses of conventional ESI-mass spectrometry (MS) interfaces by placing the emitter in the first reduced pressure region of the instrument. The new ESI emitter array design developed in this study allows individualized sheath gas around each emitter in the array making it possible to generate an array of uniform and stable electrosprays in the subambient pressure (10 to 30 Torr) environment for the first time. The utility of the new emitter arrays was demonstrated by coupling the emitter array/SPIN source with a time of flight (TOF) mass spectrometer. The instrument sensitivity was compared under different ESI source and interface configurations including a standard atmospheric pressure single ESI emitter/heated capillary, single emitter/SPIN and multi-emitter/SPIN configurations using an equimolar solution of nine peptides. The highest instrument sensitivity was observed using the multi-emitter/SPIN configuration in which the sensitivity increased with the number of emitters in the array. Over an order of magnitude MS sensitivity improvement was achieved using multi-emitter/SPIN compared with using the standard atmospheric pressure single ESI emitter/heated capillary interface.
开发了带有个体化鞘气毛细管的化学蚀刻发射器阵列，以提高亚环境压力下的电喷雾电离（ESI）效率。通过将新的发射器阵列整合到具有纳升电喷雾（SPIN）源的亚环境压力电离中，电离效率和离子传输效率均显著提高，从而在质谱分析中提供了更高的灵敏度。SPIN源通过将发射器放置在仪器的第一个减压区域，消除了传统ESI-质谱（MS）接口的主要离子损失。本研究中开发的新型ESI发射器阵列设计允许在阵列中的每个发射器周围形成个体化鞘气，从而首次有可能在亚环境压力（10至30托）环境中产生均匀且稳定的电喷雾阵列。通过将发射器阵列/SPIN源与飞行时间（TOF）质谱仪联用，证明了新型发射器阵列的实用性。使用包含九种肽的等摩尔溶液，在不同的ESI源和接口配置下比较了仪器灵敏度，包括标准大气压单ESI发射器/加热毛细管、单发射器/SPIN和多发射器/SPIN配置。使用多发射器/SPIN配置时观察到最高的仪器灵敏度，其中灵敏度随阵列中发射器的数量增加而提高。与使用标准大气压单ESI发射器/加热毛细管接口相比，使用多发射器/SPIN实现了超过一个数量级的质谱灵敏度提升。
