Mass spectrometry EI CI APCI ESI GC-MS LC-MS/MS LC-MS ToF

Outline Fundamentals Ionization Isotopes Some chromatography Applications Roles and responsibilities

Mass spectrometry Latin ”spectre” means ”image”. Word has drifted from optical spectrometry A mixture of masses can be separated and ”imaged” We get a raw look into chemistry Extremely versatile tool – the equivalent of a digital oscilloscope.

Remember this! Only IONS can be analyzed Separation based on m/z – not mass! ALWAYS done in vacuum

Mass spectrometer Ion sourceMass filter(s)Detector

m/z Rel. I Masspektrum Mass spectra

Modes GC-MS: Volatiles – solvents – reagents EI - Electron Impact is a classic CI - Chemical Ionization is difficult! LC-MS: Water soluble – proteolytes Electrospray is super mild – proteins APCI is a bit violent – hydrolyze esters

LC-MS Fundamental problem MS done in vacuum LC mobile phases DESTROY vacuum Over 20 years of hard work to solve

Kromatogram Antal scan Tid Totaljonkromatogram Total Ion Current (TIC) masspektrum vid en viss tidpunkt klemastin (Tavegyl®, antihistamin)

Summary GC-MS EI – Agressive! CI – Mild LC-MS APCI – Pretty agressive – hydrolyze esters ESI – Extremely soft – large proteins can be ionized