Analytica of Branford, Inc.

Perkinelmer Health Sciences, Inc.

Shida Shen

Craig M Whitehouse

Bruce A Andrien, Jr

Thomas P White

Michael A Sansone

John Bennett Fenn

Cawthon Smith

Thomas White

Species that may be required to enhance an upstream sample preparation or separation process may be less compatible with the downstream electrospray (ES) processes and cause reduction in mass spectroscopy (MS) signal. New electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes. The new electrolyte species increase ES MS signal when added directly to a sample solution or when added to a second solution flow in an electrospray membrane probe, it has also been found that running the ES membrane probe with specific electrolytes in the second solution of the ES membrane probe have been found to enhance ESMS signal compared to using the same electrolytes directly in the sample solution being electrosprayed. The new electrolytes can be added to a reagent ion source configured in a combination atmospheric pressure ion source to improve ionization efficiency.

Atmospheric pressure ion source performance enhancement

The instant invention deals with species that may be required to enhance an upstream sample preparation or separation process may be less compatible with the downstream ES processes and cause reduction in MS signal. New electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes. The new electrolyte species increase ES MS signal when added directly to a sample solution or when added to a second solution flow in an electrospray membrane probe, it has also been found that running the ES membrane probe with specific electrolytes in the second solution of the ES membrane probe have been found to enhance ESMS signal compared to using the same electrolytes directly in the sample solution being electrosprayed. The new electrolytes can be added to a reagent ion source configured in a combination atmospheric pressure ion source to improve ionization efficiency.

Multiple sample introduction means have been configured in Atmospheric Pressure Ion sources which are interfaced to mass analyzers. Different samples can be introduced through multiple Electrospray (ES) or Atmospheric Pressure Chemical Ionization (APCI) probes individually or simultaneously and ionized. The gas phase ion mixture resulting from individual solutions sprayed from multiple ES or APCI probe inputs is mass analyzed. In this manner a calibration solution can be introduced through one ES or APCI probe while one or more sample solutions are spray from additional probes. Simultaneous spraying of calibration and sample solutions, results in an acquired mass spectrum containing peaks of ions with known molecular weights as well as sample related peaks. The calibration peaks can be used as an internal calibration standard during data analysis. Acquisition of mass spectra containing internal calibration peaks can be achieved by spraying different solutions simultaneously from multiple inlet probes without having to mix calibration and sample solutions in the liquid phase. Arrangements of ES and APCI probes can be configured in one API source chamber and the solution flow through any combination of ES or APCI probes can be switched on or off during an analytical run. A single mass analyzer can serve as a detector for multiple separation systems each delivering sample solution through separate ES or APCI inlet probes into an atmospheric pressure ion source.

Multiple sample introduction mass spectrometry

The subject invention teaches the use of mechanical vibration to enhance the electrostatic dispersion of sample solutions into the small, highly charged droplets that can produce ions of solute species for mass spectrometric analysis. Such vibration turns out to be surprisingly effective at ultrasonic frequencies for solutions with flow rates, conductivities and surface tensions too high for stable dispersion by electrostatic forces alone as in conventional electrospray ionization. Several embodiments of the invention are described for purposes of illustration. Other possible embodiments will become apparent to those skilled in the art.

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Branford, CT, United States of America

Shida Shen