Lazar I M, Ramsey R S, Jacobson S C, Foote R S, Ramsey J M
Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, TN 37831-6365, USA.
J Chromatogr A. 2000 Sep 15;892(1-2):195-201. doi: 10.1016/s0021-9673(00)00335-6.
A novel microchip device for electrospray ionization has been fabricated and interfaced to a time-of-flight mass spectrometer. Fluid is electrokinetically transported through the chip to a fine fused-silica capillary inserted directly into a channel at the edge of the device. Electrospray is established at the tip of the capillary, which assures a stable, efficient spray. The electric potential necessary for electrospray generation and the voltage drop for electroosmotic pumping are supplied through an electrically permeable glass membrane contacting the fluidic channel holding the capillary. The membrane is fabricated on the microchip using standard photolithographic and wet chemical etching techniques. Performance relative to other microchip electrospray sources has been evaluated and the device tested for potential use as a platform for on-line electrophoretic detection. Sensitivity was found to be approximately three orders of magnitude better than spraying from the flat edge of the chip. The effect of the capillary on electroosmotic flow was examined both experimentally and theoretically.
一种用于电喷雾电离的新型微芯片装置已被制造出来，并与飞行时间质谱仪相连。流体通过芯片以电动方式传输到一根精细的熔融石英毛细管，该毛细管直接插入装置边缘的一个通道中。在毛细管尖端形成电喷雾，这确保了稳定、高效的喷雾。产生电喷雾所需的电势和电渗泵的电压降通过与容纳毛细管的流体通道接触的电渗透玻璃膜提供。该膜是使用标准光刻和湿化学蚀刻技术在微芯片上制造的。已评估了该装置相对于其他微芯片电喷雾源的性能，并测试了其作为在线电泳检测平台的潜在用途。发现灵敏度比从芯片平边缘喷雾提高了约三个数量级。通过实验和理论研究了毛细管对电渗流的影响。
