achem

electron ionization ei

volatile small gas GC MS, differentiate structural isomers

chemical ionization CI

volatile need ionizaton preserve ions molecular weight

inductively plasma ICP

elemental analysis

electrosoray ionization ESI

polar large bio molecules LC MS PROTEINS ambient

MALDI

Large biomolecules need matrix FRAGILE

ionizes large non volatile molecules by mixing them with a UV absorbing matrix pulsing a laser at the mixtutr anf lettinf thr matrix abbsob the energy and transfer cjange to the analyte as it vaporizes into gas phase.

DESI

ambient biological tissue