Mass spectrometers are effective
tools to identify and quantify unknown molecules, such as disease-related
proteins and small molecules
in pharmaceutical
research
and medical diagnosis. In addition, mass spectrometry can be particularly
powerful when analyzing molecules with complex structures, such as
post-translationally-modified proteins. Among various mass spectrometric
approaches, high-resolution
multi-step
tandem mass spectrometry is an emerging methodology for accurate identification
of complex molecules. In this article, we describe a new tool for mass
analysis with enhanced quantitative capability combined with high-resolution
multi-step
tandem mass spectrometry, where the dynamic range of quantitation covers
4 orders-of-magnitude.