Subattomole-sensitivity microchip nanoelectrospray source with time-of-flight mass spectrometry detection

摘要

A microfabricated microfluidic device coupled with a nanospray tip for electrospray ionization of dilute solutions is-described. The device has been interfaced with a time-of-flight mass spectrometer and evaluated for sensitive, high-speed detection of peptides and proteins. The electrospray: voltage was applied through the microchip to the nanospray capillary that was attached at the end of a microfabricated channel. Fluid delivery rates were 20-39 nL min(-1) through the hybridized structure without any pressure assistance. On-line microchip electrophoresis has been demonstrated and the effect of the capillary-chip junction on band broadening examined. Full mass spectra are acquired within 10-20 ms at 50-100 spectra s(-1) storage rates. Detection of subattomole levels of sample from a 100 nM solution is demonstrated for infusion experiments. [References: 21]