Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Molecules and Medicine > W8 Mass Spectromotry > Flashcards

W8 Mass Spectromotry Flashcards

You may prefer our related Brainscape-certified flashcards:
Organic Chemistry 101 flashcards
1
Q

What is mass spectrometry

A

Mass spectrometry is an analytical technique

that involves the ionisation of chemical species

then sorting of the ions based on their mass to charge ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the main things it is used for

A

Obtaining details about

  • mass of a chemical species
  • structural information about molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are advanced ms techniques used for

A

analyze complex mixtures including ones which contain biomolecules e.g. carbohydrates or proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 main areas mass spectrometry is used

A

biomolecule characterization

environmental analysis

forensic analysis/clinical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a Dalton

A

one unit of mass and is defined as 1/12th the mass of a single carbon 12 atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is an isotopologues

A

it is a molecule that differs only in isotopic composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the size of a molecule affect its chance to have a less abundant isotope

A

the larger the molecule the chance to have more than one atom of a less abundant isotope is higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a characteristic of Isotopologues on a graph

A

peak splitting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the main components of a mass spectrometre

A

the machines consist of

an ion source

mass analyzer

detector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the 1st step an ms follows

A

the sample is vaporised and ionised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the 2nd step an ms follows

A

ions subject to a filter to separate them according to their mass to charge ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the 3rd step an ms follows

A

the stream of mass separated ions are detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the 4th step an ms follows

A

an electrical output is generated producing a plot of the signal intensity for each mass to charge ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the steps an ms follows

A

the sample is vaporised and ionised

ions subject to a filter to separate them according to their mass to charge ratio

the stream of mass separated ions are detected

an electrical output is generated producing a plot of the signal intensity for each mass to charge ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the highest peak in a ms known as

A

base peak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a base peak

A

it is the highest peak in a ms and is set to 100% relative intensity

17
Q

What is a molecular ion peak

A

the signal that represents the mass of the target compound

18
Q

what is the units of the x axis in ms

A

Mass / Charge (M/Z)

19
Q

Why are there many peaks on the mass spec

A

there are many peaks as they are the fragments of the molecule

20
Q

What are the two main types of mass spectrometry techniques

A

Electron Impact Ionization (EI)

Matrix assisted laser desorption ionisation (MALDI)

21
Q

What happens in Electron Impact Ionization

A

The vaporized sample gets bombarded with high energy electrons causing an electron from the compound to be ejected.

This makes the compound a high energy charged species,

which can then breakdown into lower weight fragment ions and radicals

22
Q

What is the first step of EI MS

A

Sample vaporised and ionised

23
Q

What is the second step of EI MS

A

Ions accelerated in an electric field

24
Q

What is the third step of EI MS

A

In the magnetic sector circular flight path adopted dependent upon the mass to charge ratio

25
Q

What is the fourth step of EI MS

A

Changing magnetic field strength allows only ions of correct M/Z ratio through the detector

26
Q

What is the fifth step of EI MS

A

Spectrometer operates by sweeping the magnetic field to scan hte mass range

27
Q

What is the process of EI MS (Simplefied)

A

Sample Vaporized and Ionized

Ions accelerated

Circular flight path can be adopted dependent of mass to charge ratio

change in magnetic field allows what we want to be detected

spectrometer scans magnetic field for mass range

28
Q

what can explain fragments

A

homolyic alpha cleavage
heterolytic alpha cleave

these are both pathways that can explain

29
Q

What does homolytic alpha cleave often do

A

it often gives the most abundant ion

the radical is often used to form a double bond with the heteroatom

loss of the largest possible radical favoured

30
Q

What can we get in addition to fargmentation

A

we can also get rearrangements

31
Q

what is the mclafferty rearrangement

A

It is a process which can be undertaken by

aliphatic ketones
aldehydes that feature gamma hydrogens

(Must have at least alkyl chain of three carbons)

carboxylic acids
esters
amides

32
Q

Describe Maldi MS

A

softer low energy ionisation technique

33
Q

what happens to the sample in Maldi MS

A

mixed with a matrix compound that is a strong uv absorber

34
Q

why is the sample mixed with a strong uv absorber matrix

A

its function is to absorb energy from a pulsed ultraviolet laser and transfers it to the sample

Molecules and Medicine (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions