Signal processing method and system based on time-of-flight mass spectrometry and electronic apparatus

The signal processing method for analysis of time-of-flight mass spectra, comprising:

• filtering the detected maxima of the wavelet coefficient distribution with a preset criterion, so as to determine the position and intensity of each spectral peak therein;
• the criterion comprising one of the followings or a combination thereof:
• 1) the frequency band or scale of the maxima location is within a preset range;
• 2) the length of a corresponding ridge line reaches a preset threshold, the so-called ridge line is formed by the following steps:
• first searching the maxima on the said two-dimensional wavelet coefficient distribution and set as the starting point;
• connecting each said starting point to the neighboring maxima on the one-dimensional wavelet coefficient distribution with respect to time on the next scale/frequency band;
• extending each line to the neighboring maxima on the one-dimensional wavelet coefficient distribution with respect to time on the next scale/frequency band;
• and so forth until the upper/lower limit of the range of the scale/frequency band is reached;
• 3) the corresponding signal-to-noise ratio reaches a preset threshold.

A signal processing system for analysis of time-of-flight mass spectra, comprising:

• an raw spectrum acquisition module, which is configured to digitalize an analog signal output from an ion detector to acquire a plurality of complete raw time-of-flight spectra or acquire each effective part in a plurality of raw time-of-flight spectra one by one for a plurality of times;
• an optional extraction module, which is configured to extract the effective parts from each complete raw time-of-flight spectrum;
• a wavelet transform module, which is configured to apply a one-dimensional wavelet transform to each effective spectrum part in each of the raw time-of-flight spectra to map to each frequency band or scale;
• a peak detection module, which is configured to determine the position and intensity of each spectral peak in each raw time-of-flight mass spectrum by detecting maxima on the obtained wavelet coefficient distribution, and save said peak position and intensity as characteristic data of each spectral peak;
• and
• an analysis module, which is configured to accumulate the characteristic data of spectral peaks obtained by processing each of the raw time-of-flight mass spectra and stack the data to form a spectral peak intensity/time-of-flight histogram.