Thermo Finnigan LLC

University of New Hampshire

Linfan Li

Jae C Schwartz

Oleg Silivra

Derek J Bailey

Anyin Li

Mengtian Li

The present disclosure relates to an apparatus and method to achieve electrospray ionization at femtoliter/minute to nanoliter/minute flow rates including relatively rapid alternation between such flow rates within the same device. These flow rates provide enhanced and relatively more uniform ionization of sprayed compounds for subsequent analytical evaluations.

Capillary emitter with electrospray ionization providing femtoliter to nanoliter flow rates

A method of ion detection comprises: (a) setting electrical potentials of a dynode and a scintillator electrode of a Daly detector and of a focusing lens disposed at an ion inlet of the Daly detector so as to detect negatively charged ions received from a mass analyzer or mass filter; (b) transferring the negatively charged ions from the mass analyzer or mass filter to the Daly detector through the lens and detecting said negatively charged ions by a photodetector of the Daly detector; (c) setting electrical potentials of the dynode, the scintillator electrode and the focusing lens of the Daly detector so as to detect positively charged ions received from the mass analyzer or mass filter; and (d) transferring the positively charged ions from the mass analyzer or mass filter to the Daly detector through the lens and detecting said positively charged ions by the photodetector.

Daly detector operable in negative ion and positive ion detection modes

An ion detector that can detect either positive or negative ions comprises: an ion inlet comprising an ion focusing lens; a dynode having a surface configured to intercept, within a zone of interception, a stream of ions passing through the ion focusing lens, wherein a plane that is tangent to the dynode surface at the zone of interception is disposed at an angle to a line that passes through the center of the dynode surface and the center of the focusing lens; a scintillator having a surface that is configured to receive secondary electrons emitted from the zone of interception; a scintillator electrode affixed to the scintillator surface; a photodetector configured to receive photons emitted by the scintillator and to generate an electric signal in response thereto; and one or more power supplies electrically coupled to the focusing lens, the dynode, the scintillator electrode and the photodetector.

A method of quantitative mass analysis of precursor ion species of different mass-to-charge (m/z) ratios from the same or common ion injection event is disclosed. A plurality of precursor ion species with different respective m/z ratios are introduced into an ion trap mass analyzer at the same time. The precursor ion species are isolated. A first subset of the isolated precursor ions, which are multiply charged and have a first m/z ratio range, is fragmented and scanned by dividing the scan into at least two separate scan windows. A first mass spectrum is generated for the fragment ions of the first subset of precursor ions. A second subset of the isolated precursor ions having a second m/z ratio is fragmented and scanned, and a second mass spectrum is generated for the fragment ions of the second subset of precursor ions.

Methods and systems for quantitative mass analysis

A mass spectrometry apparatus includes an ion source, an ion trap and a mass spectrometer controller. The ion source is configured to generating ions. The ion trap is configured to trap ions within a RF field; eject unwanted ion while retaining target ions; and fragment target ions. The mass spectrometer controller is configured to determine an injection time for the ion trap based on a precursor ion flux and a product ion flux; fill the ion trap with ions from the ion source for an amount of time equal to the injection time; isolate target precursor ions in the ion trap; fragment the target precursor ions to generate product ions; and mass analyzing the product ions.

[object Object]

A method of quantitative mass analysis of precursor species of different mass-to-charge (m/z) ratios from the same ion injection event is disclosed. A plurality of precursor ion species is introduced into a mass spectrometer at the same time, and isolated. A first subset of the isolated precursor ions having a first m/z ratio and a second subset of the isolated precursor ions having a second m/z ratio are fragmented. The fragmented ions are analyzed at the same time. A mass spectrum is generated for the fragment ions of the first and second subsets of precursor ions.

A method of quantitative mass analysis of precursor species of different mass-to-charge (m/z) ratios from a single or the same ion injection event is disclosed. A plurality of precursor ion species having different respective m/z ratios are introduced into a mass spectrometer at the same time. The precursor ion species are isolated. A first subset of the isolated precursor ions having a first m/z ratio is fragmented and analyzed. A second subset of the isolated precursor ions having a second m/z ratio is fragmented and analyzed. A first mass spectrum is generated for the fragment ions of the first subset of precursor ions, and a second mass spectrum is generated for the fragment ions of the second subset of precursor ions.

Growing community of inventors

San Jose, CA, United States of America

Linfan Li