Systems and methods of operation of linear ion traps in dual balanced AC/unbalanced RF mode for 2D mass spectrometry

A method for identifying components of a sample comprising:

• supplying ions to a mass selective linear ion trap, the ion trap including a plurality of trap electrodes spaced apart from each other and surrounding a trap interior, the trap electrodes configured for generating a quadrupolar trapping field in the trap interior;
• trapping the ions within a balanced trapping field, the balanced trapping field generated by applying AC voltages to the plurality of trap electrodes such that a first pair of trap electrodes receive an AC voltage of equivalent magnitude but opposite sign to an AC voltage received by a second pair of trap electrodes;
• transitioning between a balanced trapping field to an unbalanced trapping field, the unbalanced trapping field generated by applying RF voltages to the plurality of trap electrodes such that a magnitude of the RF voltage applied to the first pair of trap electrodes is different from a magnitude of the RF voltage applied to the second pair of trap electrodes, wherein transitioning includes ramping down the AC voltages over less than about 1.5 ms and ramping up the RF voltages over between about 0.8 ms and about 2.5 ms;
• and
• maintaining the unbalanced trapping field while selectively ejecting ions from the trap interior based on their mass using an auxiliary RF voltage.