What is Mass Spectrometry (MS)?

This technique measures the mass and molecular weight of a molecule.

How do you gain structural information?

By measuring the masses of fragments produced when molecules break apart

What are the three basic parts of spectrometers?

Ionization source

Mass Analyzer

Detector

Ionization Source is what?

sample molecules are given an electrical charge

Mass analyzer is what?

ions are separated by their mass-to-charge ratio,

What is a detector?

the separated ions are observed and counted.

What is the most common spectrometer used?

The electron-impact, magnetic-sector instrument

What causes a cation radical?

A high energy electron strike

What is a cation radical?

A species with a positive charge and unpaired electrons

What is the base peak?

The tallest peak which is assigned to 100% intensity

What is the Parent peak?

The peak that corresponds to the unfragmented cation radical

What is often not the base peak?

The molecular ion

What are mass measurements taken from?

Specific isotopic compositions rather than the periodic table.

How does fragmentation occur?

when the high-energy cation radical flies apart by spontaneous cleavage of a chemical bond.

What is formed during fragmentation?

a relatively stable carbocation