title: Subattomole-Sensitivity Microchip Nanoelectrospray Source with Time-of-Flight Mass Spectrometry Detection.
abstract: 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 20-30 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.
authors.affiliation: Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6365, and Caliper Technologies Corporation, Mountain View, California 94043-2234.
authors.forename: I M
authors.initials: IM
authors.lastname: Lazar
authors.forename: R S
authors.initials: RS
authors.lastname: Ramsey
authors.forename: S
authors.initials: S
authors.lastname: Sundberg
authors.forename: J M
authors.initials: JM
authors.lastname: Ramsey