7. analytical techniques 1

Question 1

what is mass spectrometry

Answer 1

analytical technique used to identify different isotopes and find the overall atomic mass of an element

Question 2

what are the 5 steps of TOF mass spectrometry

Answer 2

1. ionisation - a sample is vapourised and ionised and injected into the mass spectrometer
2. acceleration - the ions are accelerated
3. deflection - the ions are deflected by a magnetic field into a curved path
4. detection - when the ions hit the detection plate they gain an electron producing a flow of charge. the greater the charge the higher the abundance of that particle
5. analysis - the values are used to produce a spectra print out with the abundances of each isotope

Question 3

why can half m/z ratios be seen on a mass spectrum

Answer 3

during the ionisation process 2+ ions may be produced which are affected more by the magnetic field producing a sharper curved path. as a result its m/z ratio is halved

Question 4

how to calculate the Ar from a mass spectrum

Answer 4

Ar = m/z x abundance for all m/z / total abundance

Question 5

what is infrared spectrometry

Answer 5

an analytical technique that uses infrared radiation to determine the functional groups present in organic compounds.

Question 6

how does infrared spectrometry work

Answer 6

IR radiation is passed through a sample where the different types of bonds absorb the radiation in different amounts which are recorded and identified

Question 7

what shape are OH alcohol groups

Answer 7

curved

Question 8

what share are C=C and C=O groups

Answer 8

sharp points