Mass analysis data analyzing apparatus and program thereof

Abstract

In a mass analysis data analyzing apparatus, centroid data is used as mass spectrum data to be analyzed. First, peaks on the centroid data are specified in order of intensity as a standard peak for identifying an isotopic cluster. The isotopic cluster is detected by comparing an emerging pattern of peaks near the standard peak and an emerging pattern of peaks of an expected isotopic cluster in the case where each valence is assumed. The valence of the determined isotopic cluster is set as the valence of the peaks belonging to the isotopic cluster, and the peak at the forefront of cluster is selected as a monoisotopic peak. With such a mass analysis data analyzing apparatus, it is possible to determine the valence of each peak and identify the monoisotopic peak in a mass spectrum.

1 . A mass analysis data analyzing apparatus for determining a valence of each ion peak and identifying one or more monoisotopic peaks in a mass spectrum by analyzing mass spectrum data obtained by a mass analysis, comprising:
 a) a centroid data creator for creating centroid data based on profile data obtained as the mass spectrum data; and   b) a data analyzer for detecting an isotopic cluster in the mass spectrum based on an emerging pattern of peaks on the centroid data, determining a valence of peaks in the isotopic cluster based on a detection result, and identifying a monoisotopic peak of the isotopic cluster.   
   
   
       2 . The mass analysis data analyzing apparatus according to  claim 1 , wherein the data analyzer comprises:
 c) a standard peak specifier for specifying a peak on the centroid data, in order of descending peak intensity, as a standard peak for identifying the isotopic cluster;   d) a pattern matcher for comparing an emerging pattern of peaks near the standard peak and an emerging pattern of peaks of an isotopic cluster within a predetermined valence range;   e) an isotopic cluster identifier for determining a valence of the isotopic cluster including the standard peak and for determining peaks belonging to the isotopic cluster, in a case where an emerging pattern of the standard peak and the peaks near it corresponds to the emerging pattern of peaks of the isotopic cluster as a result of a comparison by the pattern matcher;   f) a peak valence determiner for determining the valence of the isotopic cluster identified by the isotopic cluster identifier as a valence of the peaks belonging to the isotopic cluster; and   g) a monoisotopic peak identifier for identifying a peak having a smallest mass-to-charge ratio in the isotopic cluster as a monoisotopic peak.   
   
   
       3 . The mass analysis data analyzing apparatus according to  claim 2 , wherein the isotopic cluster identifier selects each candidate for the peaks belonging to the isotopic cluster by using a relative intensity to the standard peak or peaks already matched as the peaks belonging to the isotopic cluster when determining the peaks belonging to the isotopic cluster. 
   
   
       4 . A program for making a computer functionate as a mass analysis data analyzing apparatus according to  claim 1 . 
   
   
       5 . A program for making a computer functionate as a mass analysis data analyzing apparatus according to  claim 2 . 
   
   
       6 . A program for making a computer functionate as a mass analysis data analyzing apparatus according to  claim 3 .