Appearance of mass spectra

Question 1

What molecular ions does EI produce

Answer 1

Radical cations: M+

Question 2

What molecular ions does MALDI produce

Answer 2

Singly charged cations and anions: [M+H]+, [M-H]-, [M+Na]+

Question 3

What molecular ions does ES produce

Answer 3

Multiply charged cations and anions: [M+nH]n+, [M-nH]n-, [M+nNa]n+

Question 4

Alkaloid

Answer 4

Any class of naturally occurring organic nitrogen-containing bases

Question 5

What are the two types of mass

Answer 5

Nominal (rounded) and accurate

Question 6

Resolving power

Answer 6

Separate ions of same nominal mass but different accurate mass

Question 7

When are peaks considered to be fully resolved?

Answer 7

Peak width at 10% height is approx equal to m/z separation

Question 8

What is the resolving power equation

Answer 8

mass/ difference in mass between the two peaks

Question 9

When happens to Mr when resolving power increases

Answer 9

Mr increases

Question 10

Relative mass accuracy

Answer 10

Error = (mass diff/ accurate mass) x10^6

Question 11

How much 13C is in our body

Answer 11

1.1%