Lec 4 Flashcards

1
Q

The solvent poured through. It is in liquid or gas form. Also called eluent

A

Mobile phase

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2
Q

Solid base of powder packed into the column, where the mobile phase flows. Should be in solid or liquid form.

A

Stationary phase

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3
Q

The solid material which serves as the stationary phase in the adsorption chromatography.

A

Adsorbent

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4
Q

A solid material that supports the liquid film in partition chromatography.

A

Support

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5
Q

The process where mobile phase is allowed to flow over the adsorbent or support

A

Development

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6
Q

The analyte material that emerges from the chromatograph.

A

Eluate

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7
Q

Component molecules of the substance being separated. Also substances being dissolved.

A

Solutes

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8
Q

The process where the separated substances on the chromatogram are washed off the adsorbent.

A

Elution

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9
Q

It is to become separated into constituent parts. A technique developed to separate plant pigments into colored bands.

A

Resolution

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10
Q

The process of separation of a chemical mixture into different components based on their physical-chemical characteristics and interaction of molecules with the mobile and stationary phase through a support medium.

A

Chromatography

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11
Q

4 Physico-chemical properties used as a basis in the separation of soluble components in a solution

A

Differences in:
1. Adsorption to the medium
2. Relative solubilities of mobile & stationary phase
3. Ionic attraction to the sorbent
4. Penetration into a sorbent gel

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12
Q

Type of chromatography that includes:
Classical Adsorption chromatography & Ion exchange

A

Liquid-Solid

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13
Q

Type of chromatography that includes:
Classical Partition Paper Chromatography & Thin Layer Chromatography

A

Liquid-Liquid

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14
Q

Type of chromatography that includes:
Gas Liquid Chromatography

A

Gas-Liquid

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15
Q

In Adsorption:
• Mobile phase should be in ____ form.
• Stationary phase should be in ___ form.

A

• Mobile phase is in liquid or gas form
• Stationary phase is in solid or liquid form

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16
Q

In Partition:
• Mobile phase should be in ___ form
• Stationary phase should be in ___ form

A

• Mobile phase is in liquid or gas form
• Stationary phase is in liquid form

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17
Q

_____ Chromatography:

The affinity of the components of a mixture for the adsorbent and the solubility in the mobile phase result in the resolution of the mixture.

A

Adsorption Chromatography (principle)

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18
Q

The Physical forces that control Adsorption chromatography

A

Hydrogen bonding,
Electrostatic,
Dispersive interactions,
Van der Waal Forces

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19
Q

Properties of a Good adsorbent

A

• insoluble to the solvent used
• neither react with separated substance, nor catalyze their decomposition
• colorless adsorbent, if colored separated substance

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20
Q

____ Chromatography:

Separation of solutes is based on relative solubility of the organic nonpolar solvent and the aqueous polar solvent

A

Partition chromatography (principle)

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21
Q

• Organic molecules with unequal sharing of electrons
• hydrophilic
• partially soluble in water

A

Polar groups

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22
Q

• Organic molecules predominantly made of covalent bonds with equal sharing of electrons
• hydrophobic

A

Nonpolar groups

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23
Q

K = solute in stationary phase ÷ solute in mobile phase

A

Partition of Coefficient (formula)

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24
Q

The ratio of the solute’s concentration in the 2 liquids

A

Partition of Coefficient (K)

25
Q

Normal Phase Partition

A

When the mobile phase is less polar than the stationary phase

26
Q

A partition system when the mobile phase is more polar

A

Reverse Phase Partition

27
Q

____ Partition chromatography uses ________ that are:

• chemically bonded to the support
• insoluble to the mobile phase

A

Modern Partition chromatography uses pseudo-liquid stationary phases that are…..??

28
Q

The characteristics of a good support:

A

retains stationary phase
exposes a large surface area to the mobile phase
mechanically stable
impedes solvent flow
• has adsorptive properties
inert to the separated substances

29
Q

• one of the 3 most common solid support used
• Strong adsorptive properties
• retains 50% to 75% of water

A

Silica gel

30
Q

• one of the 3 most common solid support used
• permits separation of large quantities of materials

A

Cellulose powder

31
Q

Commercially available as kieselguhr or Celite

A

Diatomaceous Earth

32
Q

• beads of cross-linked dextran
• granular, hydrophilic, water-insoluble, porous

A

Sephadex

33
Q

Agarose
• CANNOT stand pressure >800 psi

A

Sepharose

34
Q

Polyacrylamide

A

Bio Gel P

35
Q

• most common gel type under Steric Exclusion
resistant to pressure >800 psi

A

Water-silica-based product

36
Q

• Mobile Phase is an aqueous solvent
• Stationary Phase is a gel

A

Steric Exclusion / Molecular Exclusion

37
Q

It consists of a reversible exchange of ions between solid and liquid phases

A

Ion exchange chromatography

38
Q

Column Chromatography:
3 supports used to retain the solid phase at the bottom of the column.

A

Glass wool plugs,
Filter paper,
Sintered glass disks

39
Q

A Packing technique wherein the adsorbent is introduced into the column.

A

Dry packing

40
Q

A packing technique wherein the adsorbent & solvent are poured into the column

A

Wet Packing

41
Q

Descending Chromatography

A

The solvent moves by gravitational flow

42
Q

Ascending chromatography

A

The solvent runs upwards by capillary action

43
Q

Support medium for Paper Chromatography

A

• Whatman paper (a-cellulose of high purity)
• KIMTEC Chromatography paper

44
Q

Paper Chromatography:
Methods used for Detection

A
  1. Color reactions
  2. Radioactivity scanning
  3. Fluorescence
  4. UV absorption
  5. Infrared absorption
45
Q

It designated the degree of Monochromacity of a filter

A

Spectral band width

46
Q

3 situations wherein you Calibrate the instrument (spectrophotometer)

A

Malfunction of instrument,
When newly installed,
Periodic calibration

47
Q

A graph that shows the pattern of absorbances by a solute at different wavelengths.

A

Spectra Absorption graph

48
Q

Spectra Absorption Graph (purpose)

A

To determine the highest absorbance at different wavelengths

49
Q

Wavelength of choice. The wavelength which gives the highest absorption reading.

A

Analytical wavelength

50
Q

5 ways to eliminate stray radiation

A
  1. Change the light source
  2. Verify wavelength calibration
  3. Seal light leaks
  4. Realigning instrument components
  5. Cleaning optical surfaces
51
Q

The basic components of High Performance of Liquid Chromatography (HPLC)

A

Sample injection,
Pump,
Detector,
Recorder

52
Q

It is used to identify compounds when compared with standard retention volumes that is run under identical conditions.

A

Retention volume

53
Q

____ retention volume is when the solute has less affinity with the stationary phase

A

Low retention volume

54
Q

___ retention volume is when the solute has the highest affinity with the stationary phase

A

Greatest retention volume

55
Q

The time required for the sample to elute from the column

A

Retention Time

56
Q

It has short retention time which means poor separation.

A

Early eluting compounds

57
Q

It has long retention time which means decreased sensitivity.

A

Late eluting compounds

58
Q

The substance’s affinity to the liquid stationary phase over the gaseous mobile phase

A

Gas chromatography (principle)