Trapped Ion Mobility Spectrometry (TIMS) is a separation technique in the gas phase, which resolves sample complexity with an added dimension of separation in addition to HPLC and mass spectrometry, increasing peak capacity and confidence in the compound characterization. TIMS device also serves to accumulate and concentrate ions of a given mass and mobility, enabling a unique increase in sensitivity and speed along with the additional dimension of separation.

timsTOF Technology

In this technique, ions are propelled through the TIMS tunnel by a gas flow. An electrical field controls each ion from moving beyond a position defined by the ion’s mobility, where the push it experiences from the gas flow matches the force of the electrical field. Ramping down the electrical field allows selectively releasing ions from the TIMS tunnel according to their mobility. By incorporating a TIMS device at the front of a quadrupole time-of-flight (QTOF) mass spectrometer, ions can be accumulated for a specific amount of time before being released for MS analysis.

Using the PASEF® method, peptide ions are separated using TIMS, eluted (~ 100 ms), and detected in the QTOF, generating the TIMS MS heat map. In the PASEF® method, the same TIMS separation is used with the quadrupole isolating a certain ion species during its elution and immediately shifting to the next precursor. Parent and fragment spectra are aligned by mobility values. With PASEF® technology >100 Hz sequencing speed can be achieved, and the MS/MS spectra quality of low abundant peptides can be increased by selecting them several times.