Chen Lee Chuin, Tsutsui Satoru, Naito Tsubasa, Ninomiya Satoshi, Hiraoka Kenzo
Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi, 400-8511, Japan.
Clean Energy Research Center, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi, 400-8511, Japan.
J Mass Spectrom. 2018 May;53(5):400-407. doi: 10.1002/jms.4072.
A new electrospray source design is introduced by having an extractor electrode placed at 1 to 2 mm behind the emitter tip. The extractor was integrated into the sprayer body as a single device. An insulating tube was used to isolate the emitter from the extractor and to deliver the sheath gas for the electrospray. The electric field strength at the emitter was primarily determined by the relative position and the potential between the needle and the extractor; therefore, the spraying condition was insusceptible to the change of sprayer position or orientation with respect to the ion sampling inlet. Such design allowed the use of much lower operating voltage and facilitated the optimization of sprayer position by keeping the electric field parameter constant. Using an emitter capillary of 150 and 310 μm in inner and outer diameters, strong ion signal could still be acquired with 2-kV emitter potential even if the distance between the emitter and ion inlet was extended to >70 mm. Charge reduction of protein ions using 2 extractor-based electrosprays of opposite emitter polarities was also demonstrated.
通过将提取电极放置在发射极尖端后方1至2毫米处，引入了一种新的电喷雾源设计。该提取器作为一个单一装置集成到喷雾器主体中。使用绝缘管将发射极与提取器隔离，并为电喷雾输送鞘气。发射极处的电场强度主要由针与提取器之间的相对位置和电位决定；因此，喷雾条件不受喷雾器相对于离子采样入口的位置或方向变化的影响。这种设计允许使用低得多的工作电压，并通过保持电场参数恒定来促进喷雾器位置的优化。使用内径为150μm、外径为310μm的发射极毛细管，即使发射极与离子入口之间的距离延长至>70mm，在2kV发射极电位下仍可获得强离子信号。还展示了使用基于提取器的两种具有相反发射极极性的电喷雾来减少蛋白质离子电荷的方法。
