Study of ionization efficiency on silicon-based, micro-fabricated electrospray nozzles for micro flow LC/ESI-MS applications

One of the benefits of nanoelecrtospray ionization (nanoESI) is the reported optimal ionization efficiency (equalized response) of chemically different analyses despite the presence of matrix components. However, outside of a very low flow rate of ca. 1-20 nL/min, the ionization efficiency drops exponentially and coupling higher flow rates from a typical liquid chromatography (LC) system to ESI loses most of the benefits such as enhanced sensitivity and reduced ion suppression in mass spectrometry analysis (LC/ESI/MS). The Advion silicon-based ESI Chip accommodates micro flow LC/MS applications at ionization efficiencies near optimal levels and comparable to nanoelectrospray ionization (nanoESI).