Common Spurious Signals Observed in Mass Spectrometers
Thomas J. Bruno, Paris D. Svoronos
The following table provides guidance in the recognition and interpretation of spurious signals (m/z peaks) that will sometimes be observed in measured mass spectra . Often, the occurrence of these signals can be predicted by the recent history of the instrument or the method being used. This is especially true if the mass spectrometer is interfaced to a gas chromatograph.
CRC Handbook of Chemistry and Physics - 93rd edition