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Flashcards in Chromatography And Mass Spectrometry Deck (36):
1

Refers to the group of techniques used to separate complex mixtures on the basis of different physical interactions between the individual compounds and the stationary phase of the system

Chromatography

2

Basic components in any chromatographic technique

Mobile phase (gas or liquid; carries sample)
Stationary phase (solid or liquid; where mobile phase flows)
Column holding the stationary phase
Eluate

3

What is measured in simple chromatography?
***

Distances of the separated components are compared relative to the baseline or origin set from the start

4

SP and MP in simple chromatography

SP: paper
MP: solvent

5

The farthest point the solvent reached

Solvent front

6

A ratio of the distance travelled by the component to the distance travelled by the solvent

Retention factor (distance of component/distance of solvent)

7

Relationship of rf and solubility

Directly proportional

8

What is implied when rf value= 1

The solute has no affinity for the stationary phase and travels with the solvent front

9

Types of chromatography

Paper
Thin layer
Gas
Etc

10

It is a variant of column chrom and almost same as paper but glass coated by thin layer of film (alumina, paper, silica gel, cellulose) is used as sorbent and positioned at an angle

Thin layer

11

Gas chrom is used to separate what?

Mixtures of compounds that are volatile or can be made volatile

12

Applications of gas chromatography

Analysis of neutral and acidic drugs
Urine toxicological tests
Identify various types of alcohols

13

Process of gas chrom

→ Solution is vaporized, transferred to column of gas
→ Compounds separate according to volatility and polarity
→ Gas passes through a detector where it is identified
→ Chromatogram is generated (based on detector intensity over time)

14

Retention time in gas chrom is based on

Analytes that elute

15

Gases often used in gas liquid chrom

Helium, nitrogen or hydrogen

16

T or F: gases of higher weights are nearer to the detector within the column and moving more rapidly while lower weights are closer to the sample injector

False, high-sample injector, low- detector in column, moves rapidly

17

Compounds with _____ boiling point will move slowly in gas chrom

Higher

18

Molecules which are more abundant in stationary or liquid phase (less volatile) will be ______________, those with more abundance in the gas phase (more volatile) will be ______________

Molecules which are more abundant in STATIONARY OR LIQUID phase (LESS VOLATILE) will be nearer to the sample injector, those with more abundance in the GAS phase (more volatile) will be further into the column

19

An analytical technique that ionizes chemical species and sorts the ions based on their mass-to-charge ratio

Mass spectrometry

20

How are the said chemical species ionized?

• Ionization is changed by removing or charging electrons in a chemical species

21

Differentiate mass spectrum and mass spectrometer

A mass spectrum measures the masses within a sample; A mass spectrometer produces charged particles (ion) from the chemical substances that are to be analyzed, which then uses electric and magnetic fields to measure the mass (‘weight’) of the charged particles

22

Atoms of the same element with differing numbers of neutron and different masses.

Isotopes

23

Atomic number is the______
Mass number is the ________

Protons; total # of protons and neutrons

24

Tells the mass number and percent abundance for isotopes wherein charged plates create an environment of high kinetic energy to charge the entering particles

Mass spectrometer

25

In a mass spectrometer, what happens when positive charges pass through negative plates with the same kinetic energy?

They accelerate kinetic field

26

T or F: the lighter isotopes with the lower mass number move faster and will get to the detector earlier

True

27

What does the detector do in a mass spectrometer?

Compares the isotopes that arrive and the time it takes to arrive. It only measures time which is used to calculate mass and abundance

28

What does the peak of te graphs denote in a mass spectrometer graph?

Relative? abundance

29

T or F: the slower the isotope, the later it appears in te graph

True

30

T or F: the graphs in mass spectrometer can differentiate between the total number of protons and neutrons

False, it cant; more advance tests must be used

31

What are the six steps in mass spectrometry?

→ Injection (The species is introduced into the spectrometer)
→ Vaporizer (Molecules are converted to gas via heat)
→ Ionization (high voltage) (The vapors are bombarded by an electron beam, converting the vapor into ions (Electron Ionization))
→ Acceleration (The double negative plate creates a kinetic filed causing the ions to accelerate)
→ Ion Drift (The species travels across the medium)
→ Detector (Detects the analytes)

32

Step in MS wherein vapors are bombarded by an electron beam, converting the vapor into ions

Ionization (3rd)

33

Step in MS wherein species is introduced into te spectrometer

Injection (1st)

34

Step in MS wherein species travel across the medium

Ion drift

35

Step in MS where molecules are converted to gas by heat

Vaporization

36

Step in MS wherein the double negative plate creates a kinetic field causing the ions to accelerate

Acceleration