Mass Spectrometry

Question 1

How does mass spec work

Answer 1

Vaporises sample

Changes to positively charged ions

Question 2

What are the uses of mass spec

Answer 2

RAM of element
RFM of compound
Existence of isotopes + relative abundances
Molecular groups in compounds - fragmentation pattern
Identify structure
Mechanism of a reaction

Question 3

What is the definition of an m+1 peak

Answer 3

Peak produced by a molecular ion with an increased mass due to the presence of one c-13 atom

Question 4

What does the m+1 peak allow you to measure and what is the % abundance of one c13

Answer 4

The number of C in a molecule

1.1%

Question 5

What is the general equation when a molecular ion is formed

Answer 5

M(g) ➡️ M+(g) + e-

Question 6

What is the definition of a fragmentation ion

Answer 6

A positively charged ion produced when the molecular ion breaks apart

Question 7

What is the definition of a molecular ion peak

Answer 7

Peak formed by an ion formed by the removal of one e- from a molecule

Question 8

What is the definition of base peak

Answer 8

Peak of greatest abundance in a mass spectrum