Causes of Disorder in Peptide Mass Spectrometry Peaks

1. Sample Purity Issues

If the sample contains multiple different peptides, the mass spectrum will display many different peaks, resulting in a very cluttered spectrum. Therefore, the purity of the sample should be improved as much as possible before mass spectrometry analysis.

2. Incomplete Peptide Cleavage

During the enzymatic cleavage of peptides, if cleavage is incomplete, larger peptide fragments may form, resulting in additional peaks in the mass spectrum.

3. Incomplete Peptide Fragmentation

During mass spectrometry analysis, peptides are fragmented in the collision cell. If fragmentation is incomplete, it will result in peaks with high mass-to-charge ratios in the spectrum.

4. Instrumental Error

Instrumental error can also lead to chaotic mass spectrum peaks. For example, insufficient resolution of the mass spectrometer can cause peak overlap, and inaccurate mass calibration can result in peak position shifts.

5. Chemical Noise

During mass spectrometry analysis, impurities in the sample solution can generate chemical noise, contributing to the disorder of the mass spectrum peaks.