Organic Analysis

Question 1

What does mass spectrometry determine

Answer 1

Ar

Question 2

What two factors does mass spectrometry measure

Answer 2

•relative abundance
•mass/charge ratio

Question 3

Step 1 of mass spectrometry

Answer 3

1. Vacuum- prevents collision of air molecules

Question 4

Step 2 of mass spectrometry

Answer 4

2. Ionisation- gain positive charge through electrospray/ electron impact

Question 5

Step 3 of mass spectrometry

Answer 5

3. Acceleration- positive ions attracted to negative plate. All ions have the same kinetic energy

Question 6

Step 4 of mass spectrometry

Answer 6

4. Ion drift- once in the flight tube, the ions drift further apart. Ions with a smaller mass travel at a faster speed

Question 7

Step 5 of mass spectrometry

Answer 7

5. Detection- ions gain electron at detector which generates a current. Size of current is proportional to size of each type of atom

Question 8

Step 6 of mass spectrometry

Answer 8

6. Data analysis- signal is passed to computer which generates a mass spectrum

Question 9

What is the process of mass spectrometry?

Answer 9

1. Vacuum- prevents collision of air molecules
2. Ionisation- gain positive charge through electrospray/ electron impact
3. Acceleration- positive ions attracted to negative plate. All ions have the same kinetic energy
4. Ion drift- once in the flight tube, the ions drift further apart. Ions with a smaller mass travel at a faster speed
5. Detection- ions gain electron at detector which generates a current. Size of current is proportional to size of each type of atom
6. Data analysis- signal is passed to computer which generates a mass spectrum

Question 10

Process of electrospray ionisation

Answer 10

•sample is dissolved in a volatile solvent
•injected through thin needed
•with high voltage
•each particle gains a proton

Question 11

Process of electron impact ionisation

Answer 11

•high energy electrons
•fired at sample
•with an electron gun
•knocks off an electron from each particle

Question 12

How does infrared work

Answer 12

•Covalent bonds have different strengths because of different atoms at each end
•bonds vibrate at different frequencies
•infrared is absorbed by bonds which vibrate at the same frequency as infrared energy

Question 13

Position of peaks in infrared spectroscopy depends on…

Answer 13

•bond strength
•mass of atoms in the bond

Question 14

The finger print region is…

Answer 14

Below 1500cm-1