Mass spectrometry 3

Question 1

How to interprate MS?

Answer 1

1. general inspection
2. Identify highest m/z (take isotopes into account)
3. Are there A+2 elements ?
4. Use above and find potential molecular formulae
5. Check if fromulae can explain OE+.
6. Derive structure using all information

Question 2

Electronegative atom tends to carry + charge. TRUE OR FALSE?

Answer 2

TRUE

Question 3

In a-cleavage bond is alpha position is the site of ionisation . TRUE OR FALSE?

Answer 3

TRUE

Question 4

Molecular rearrangement prior to fragmentation is more likely to occur if a ring is present. TRUE OR FALSE?

Answer 4

TRUE

Question 5

diels-alder fragmentation can occur with ring systems and provide an example. TRUE OR FALSE?

Answer 5

TRUE

e.g limonene

Question 6

Drugs with extensive ring structures tend to have large molecular ion peaks if , no side chains and side chains without hetero atoms to direct cleavage. TRUE OR FALSE?

Answer 6

TRUE

Question 7

What are the ppliactions of LC-MS in pharmacy?

Answer 7

• Quality control -determination of impurities
• Use in drug discovery
• Drug formulation - degradation
• Profiling impurities and degradants