The quadrupole transmits or selects ions according to their mass-to-charge ratios before they enter the later stages of analysis. This filtering step determines which ions undergo further examination and helps organize measurements from a complex molecular sample. By controlling the ions that proceed, the instrument can focus structural analysis on selected mass-to-charge signals.
Collision-induced dissociation breaks selected ions into smaller ions before time-of-flight separation. The resulting products provide structural information that cannot be obtained from molecular mass alone. Comparing the masses of the original and fragment ions helps characterize molecules, making this process especially valuable for peptide sequencing and biomolecule identification.
In the time-of-flight analyzer, ions are separated according to how quickly they reach the detector. Their arrival behavior is related to mass-to-charge ratio, allowing the instrument to distinguish ions and measure their molecular masses with high accuracy. This capability supports confident analysis when biological samples contain multiple molecules with closely related signals.
A typical workflow begins by transmitting or selecting ions with the quadrupole, followed by collision-induced dissociation of the selected ions. The resulting ions then pass through the time-of-flight analyzer, where their arrival times separate them for detection. Researchers interpret the measured mass-to-charge values and fragment information together to identify or characterize molecules.
The platform is suited to high-resolution proteomics, metabolomics, peptide sequencing, and biomolecule identification. These applications use accurate molecular-mass measurements to detect or characterize molecules and use fragment-ion information to investigate structure. Its combination of mass accuracy and structural data makes it useful for examining complex biological samples rather than relying on mass measurement alone.
Q-tof analysis can provide both accurate molecular-mass measurements and structural information from the same analytical process. Mass-to-charge signals help distinguish and identify molecular components, while ions produced by collision-induced dissociation contribute evidence about molecular structure. In biology, this combined information supports interpretation of peptides, metabolites, proteins, and other biomolecules in complex samples.