Structural elucidation of intact heavy molecules and molecular complexes in mass spectrometers

A method for the structural elucidation of pluralities of heavy molecular ions and molecular complex ions, each having a charge-related mass m/z of greater than 2000 daltons, in a linear radio frequency multipole collision cell which has an arrangement of a plurality of elongated electrodes situated in parallel to one another about a common axis, wherein all of the elongated electrodes of the collision cell together encompass a rotational symmetry about the common axis larger than twofold, comprising:

• accelerating the heavy molecular ions and molecular complex ions, which include multiply charged ions, to a predetermined kinetic energy of approximately 100 to 300 electron volts per surplus charge using acceleration voltages and axially injecting them into the linear collision cell,
• carrying out collisionally induced fragmentation without a DC potential enveloping the linear radio frequency multipole collision cell, brought about substantially by the predetermined kinetic energy of the axial injection, in the linear collision cell in a mixture of a light collision gas and a heavy collision gas, wherein the heavy collision gas has a molecular mass of at least approximately 80 daltons, and the light collision gas has a molecular mass of approximately 40 daltons at most, and
• conducting any heavy molecular ions and molecular complex ions remaining from the pluralities of heavy molecular ions and molecular complex ions after the collisionally induced fragmentation, as well as fragment ions resulting from the collisionally induced fragmentation, out of the linear collision cell to a mass analyzer.