Frequency scan linear ion trap mass spectrometry

A linear ion trap mass spectrometer for obtaining a mass spectrum of biomolecular ions, the linear ion trap mass spectrometer comprising:

• a single, non-segmented two dimensional linear ion trap for trapping and ejecting the ions having x and y electrodes consisting of two slotted x electrode rods and two y electrode rods in a quadrupole arrangement, and wherein the two dimensional linear ion trap is the only ion trap used;
• two power amplifiers to apply opposite phases of trapping RF to the x and y electrodes, wherein the two power amplifiers synchronize the two x and two y quadrupole rods, wherein each power amplifier is tuned with a capacitance to provide the same amplitude of RF as the other amplifier and a fixed degree of phase difference of the RF to the x and y electrodes during a stepwise, RF frequency scan with fixed amplitude;
• wherein the phase of the scanning RF and trapping RF are matched, wherein the RF phases are also matched to the timing of laser shots which generate the ions, and wherein the ions have an m/z of at least 150,000 Da/q;
• an inductance forming an LC circuit with the capacitance of the ion trap;
• a first end cap plate perpendicular to the electrode rods at a first end of the linear ion trap and a second end cap plate perpendicular to the electrode rods at a second end of the linear ion trap, wherein the first end cap defines an opening for a sample probe, and wherein the second end cap defines an opening for exit of ions and for passing a laser beam, wherein the end plates confine or release ions in the z axial direction with an axial trapping field.