3.5 Mass Spectroscopy Flashcards Preview

Chemistry Unit 1 > 3.5 Mass Spectroscopy > Flashcards

Flashcards in 3.5 Mass Spectroscopy Deck (20)
Loading flashcards...
0
Q

How are atoms ionised in mass spectroscopy?

A

Gaseous atoms are bombarded by electrons with sufficient energy to form +1 charge

1
Q

How does mass spectroscopy work?

A
Sample vaporised
Ionised
Accelerated
Deflected
Detected
2
Q

How are atoms accelerated in mass spectroscopy?

A

Charged ions are accelerated by an electric field by repulsion

3
Q

How are atoms deflected in mass spectroscopy?

A

Charged particles will be deflected by a magnetic or electric field
Heavier isotopes are deflected less

4
Q

How are atoms detected in mass spectroscopy?

A

Electric or photographic methods

5
Q

How are different isotopes detected in mass spectroscopy?

A

Radius of path depends on mass charge ratio
Heavier isotopes have larger m/z values so follow a larger radius curve
Most change is due to mass because they have the same charge
Heavier isotopes are deflected less

6
Q

What would happen if an ion acquires a +2 charge?

A

It will be deflected more

M/z value is halved

7
Q

What is a mass spectrum and what does it tell you?

A

Results of mass spectroscopy
Positions of peaks give atomic masses
Peak intensity gives relative abundance
Abundance adds up to 100%

8
Q

What is an atomic mass unit?

A

The mass of a carbon-12 atom divided by 12

9
Q

What instrument is used to measure the mass of atoms?

A

Mass spectrometer

10
Q

What does the velocity sector do in a mass spectrometer and why is it important?

A

Makes sure atoms are travelling at the same speed so in the next section it will only be affected by mass or charge

11
Q

What does the amount atoms are deflected by depend on in mass spectroscopy?

A

Mass and charge on ion

12
Q

Why is the strength of the magnetic field steadily increased in mass spectrometry?

A

To allow other ions to pass through as only one particular mass charge ratio will pass through and be detected

13
Q

What does the detector ultimately show in mass spectrometry?

A

The ratio of ions that pass through at each setting and each setting of the velocity flashcards

14
Q

What do the peaks in a mass spectrum tell you?

A

The relative abundance

15
Q

Where is mass spectrometry being used more?

A

Pharmaceutical industries

16
Q

Why is a mass spectrometer such a useful tool?

A

Sensitive to allow small samples

Tell difference between similar compounds which have same atoms in different arrangements

17
Q

Which other technique is mass spectrometry often used with?

A

High -Performance Liquid Chromatography (HPLC)

18
Q

How many compounds make it past the early stages of drug development

A

One compound in every 4000-10000

19
Q

Give two uses of mass spectrometry used with HPLC throughout the development of a new drug?

A

Identify the breakdown products of a drug in the body

Assessing the purity of a sample