High-resolution mass spectrometer and methods for determining the isotopic anatomy of organic and volatile molecules

A mass spectrometer comprising:

• an entrance slit having a width, the slit configured to guide a first output of molecular analyte ions along a path, the molecular analyte ions of the first output having energy levels;
• an energy filter positioned along the path downstream from the entrance slit and configured to receive the first output of molecular analyte ions, the energy filter having a first radius of curvature along the path, the energy filter configured to filter the molecular analyte ions of the first output according to their energy levels and produce a second output of molecular analyte ions;
• a momentum filter positioned downstream from the energy filter and configured to receive the second output of molecular analyte ions, the momentum filter having a second radius of curvature along the path, the momentum filter configured to filter the molecular analyte ions of the second output according to their momenta and produce a third output of molecular analyte ions, the third output of molecular analyte ions comprising at least two ion beams;
• and
• a detector array positioned downstream of the momentum filter and configured to receive the third output of molecular analyte ions and resolve and concurrently detect the at least two ion beams,
• wherein the width and the first and second radii of curvature are selected to provide a mass resolution at the detector array of 20,000 or greater.