Help on Understanding and Interpreting Mass Spectra

What is ionisation?

Electron Ionisation (EI); Chemical Ionisation (CI); Electrospray Ionisation (ESI); Atmospheric Pressure Chemical Ionisation (APCI) & Matrix Assisted Laser Desorption Ionisation (MALDI)

Sample considerations

EI / CI; ESI / APCI / MALDI & Reporting data

Interpretation of spectra

API and Electrospray: positive ion, negative ion & multiply charged molecules

Contamination Peaks - Positive Ion Electrospray

Commonly observed peaks arising from contaminants; click on the appropriate number to show ion type and contaminant.

Contamination Peaks - Other Electrospray

Cluster Ions and PEG Polymers