ISOTOPE-LABELED PYRYLIUM COMPOUND

摘要

The present invention provides: a compound represented by formula (I) or a salt thereof; a method for quantitatively analyzing a target substance containing an amino group, which comprises labeling the target substance in at least two samples by the isotopic labeling respectively using, as labeling compounds, at least two types of the compounds or salts thereof that have different masses from each other so that the mass of the target substance in one of the samples can be different from the mass of the target substance in the other of the samples; and others.