QTOFs
QTOF stands for Quadrupole Time-of-Flight mass spectrometer, a hybrid instrument that combines a quadrupole mass filter with a time-of-flight analyzer to measure the mass-to-charge ratio of ions with high speed and accuracy. Ions are typically generated by electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) and enter the instrument through the source. A quadrupole can act as a precursor selector for MS/MS experiments or function in full-scan mode. After selection, ions are accelerated into the time-of-flight region, where their flight times are recorded and converted to m/z values. Many QTOFs include a collision cell for controlled fragmentation and a reflectron to enhance resolution and mass accuracy.
Operation and performance characteristics vary by model but share common strengths. The combination of a quadrupole
Applications and data strategies. QTOFs are widely used in proteomics, metabolomics, and small-molecule analysis, as well