Apparatus for mass analysis of analytes by simultaneous positive and negative ionization

An apparatus for ionizing target molecular analytes comprising:

• a first ion source comprising an electron beam, the first ion source configured to emit positively-charged molecular ions and fragment ions and operate at approximately 70 eV;
• a second ion source comprising an electron beam, the second ion source configured to emit negatively-charged molecular ions and fragment ions and operate at between 0 to 10 eV,
• wherein the second ion source is tunable in order to better achieve frequencies that are resonant with electron capture ionization of target analytes, and
• wherein the second ion source comprises an electron deflecting region defined by a path of the election beam of the second ion source, wherein electrons enter the electron deflection region at a point that can be offset from their outlet due to motion of electrons;
• a first set of collimating electrodes arranged along a path of the electron beam of the first ion source;
• a second set of collimating electrodes arranged along a path of the electron beam of the second ion source;
• a first set of electron collectors and electron target plates arranged along the path of the electron beam of the first ion source;
• a second set of electron collectors and electron target plates arranged along the path of the electron beam of the second ion source;
• a single ionization chamber comprising a first inlet for the electron beam of the first ion source and a second inlet for the electron beam of the second ion source, the single ionization chamber configured to emit ions along an output path for ions from the first ion source and the second ion source;
• a mass analyzer configured to analyze ions from the first ion source and the second ion source;
• and
• wherein a split ratio of molecules between the first ion source and the second ion source can be tuned to meet requirements of an individual analysis.

An apparatus for ionizing target molecular analytes comprising:

• a first ion source comprising an electron beam, the first ion source configured to emit positively-charged molecular ions and fragment ions and operate at approximately 70 eV;
• a second ion source comprising an electron beam, the second ion source configured to emit negatively-charged molecular ions and fragment ions and operate at between 0 to 10 eV,
• wherein the second ion source is tunable in order to better achieve frequencies that are resonant with electron capture ionization of target analytes, and
• wherein the second ion source comprises an electron deflecting region defined by a path of the election beam of the second ion source, wherein electrons enter the electron deflection region at a point that can be offset from their outlet due to motion of electrons;
• a first ionization chamber comprising an inlet for the electron beam of the first ion source, the first ionization chamber configured to emit ions along an output path for ions from the first ion source;
• a second ionization chamber comprising an inlet for the electron beam of the second ion source, the second ionization chamber configured to emit ions along an output path for ions from the second ion source;
• a first mass analyzer configured to analyze ions from the first ion source;
• and
• a second mass analyzer configured to analyze ions from the second ion source;
• wherein a split ratio of molecules between the first ion source and the second ion source can be tuned to meet requirements of an individual analysis;
• wherein gas-phase molecules encounter incident electrons from the first ion source, producing positively-charged molecular ions and/or fragment ions, and gas-phase molecules pass through the second ion source, generating negatively-charged ions;
• and
• wherein the apparatus is configured for simultaneous ionization of compounds by their characteristic positive-ion mass fragment spectrum from the first ion source and by their negative-ion mass spectrum from the second ion source.