| 摘要 |
<p>A method of mass spectrometry comprises using a separator (e.g. ion mobility separator, chromatography, scanned differential mobility, FAIMS) to vary the intensity profile of ions as a function of time. Precursor ions are subjected to reactions or fragmentation to produce product ions. Intensity profiles are recorded for precursor and product ions as a function of time (e.g. elution time). The method comprises identifying a precursor ion in the precursor mass spectra that has a predetermined mass difference to a product ion in the product mass spectra, wherein the mass difference may be associated with the loss or gain of neutral function groups or adduct ions. The intensity profile of the precursor ion is compared with that of product ion to determine whether the precursor ion is an ion of interest, e.g. by comparing the elution times or by matching the shape of the intensity profiles. When a candidate ion is identified, a third mode may be enabled wherein the ion of interest is isolated and fragmented or reacted in order that the fragment or daughter or product ion may be analysed.</p> |
