Chromatography – Questions & Correct Answers
List separation techniques ✔️Ans - Crystalization
Distillation
Electrophoresis
Extraction
Chromatography
What are the components of extraction ✔️Ans - Liquid/liquid
extraction/partitioning
For example: salad dressing, extracting drugs
Two distinct layers (immiscible) : organic and aqueous
What is the extraction ratio ✔️Ans - Distribution ratio:
KD = (solute, organic)/ (solute, aqueous)
Describe free vs salt form of drugs ✔️Ans - Free form of drug: More Soluble
in organic layer- (salt to salt or acid to acid)
Salt form of drug (ionized form): More soluble in aqueous layer (acid and
basic)
Describe Acid drugs ✔️Ans - Acidify sample. Drug is now in the free form
and readily goes into the organic solvent.
For aqueous analysis, back-extract into base.
Describe basic drugs ✔️Ans - Make sample basic.
Drug is now in the free form and goes into the organic layer.
For aqueous analysis, back-extract into acid
Describe amphoteric and neutral drugs ✔️Ans - Sometimes difficult to deal
with, but many will go into organic solvents
Some can be extracted
Describe back extraction ✔️Ans - organic to aqueous (need drug in salt
form) so put it in unlike media.
Why do we extract ✔️Ans - 1. To PURIFY a sample
All extractions do this
, 2. Some used To CONCENTRATE a sample
Some extractions do this
What are the uses of chromatography ✔️Ans - Separate compounds of
interest
Qualitative
- To identify, or help to identify, a compound
Quantitative:
-How much of the substance is present
Define Chromatography ✔️Ans - Definition: Chromatography is a method of
analysis in which the flow of solvent or gas promotes the separation of
substances by differential migration from a narrow initial zone in a porous
absorptive medium.
What kind of struggle exists in chromatography ✔️Ans - Mobile phase
(Solvent or gas)
Stationary phase (tries to hold onto compounds)
Porous absorptive medium
How do the mobile and stationary phase work (describe attractions) ✔️Ans -
The mobile phase wants to move the compounds along rapidly, but the
stationary phase has a certain attraction for each compound. If these
attractions vary in strength from one compound to another, a separation of
the compounds can be achieved.
What are the subclasses of liquid chromatography ✔️Ans - Column L.C.:
Adsorption or Partition
HPLC (high pressure): Partition
"Flat":T.L.C. or Paper
Gel Filtration/ Gel Permeation: Adsorption
Ion Exchange
What are the subclasses of gaseous mobile phase chromatography ✔️Ans -
G.L.C.: Partition
List separation techniques ✔️Ans - Crystalization
Distillation
Electrophoresis
Extraction
Chromatography
What are the components of extraction ✔️Ans - Liquid/liquid
extraction/partitioning
For example: salad dressing, extracting drugs
Two distinct layers (immiscible) : organic and aqueous
What is the extraction ratio ✔️Ans - Distribution ratio:
KD = (solute, organic)/ (solute, aqueous)
Describe free vs salt form of drugs ✔️Ans - Free form of drug: More Soluble
in organic layer- (salt to salt or acid to acid)
Salt form of drug (ionized form): More soluble in aqueous layer (acid and
basic)
Describe Acid drugs ✔️Ans - Acidify sample. Drug is now in the free form
and readily goes into the organic solvent.
For aqueous analysis, back-extract into base.
Describe basic drugs ✔️Ans - Make sample basic.
Drug is now in the free form and goes into the organic layer.
For aqueous analysis, back-extract into acid
Describe amphoteric and neutral drugs ✔️Ans - Sometimes difficult to deal
with, but many will go into organic solvents
Some can be extracted
Describe back extraction ✔️Ans - organic to aqueous (need drug in salt
form) so put it in unlike media.
Why do we extract ✔️Ans - 1. To PURIFY a sample
All extractions do this
, 2. Some used To CONCENTRATE a sample
Some extractions do this
What are the uses of chromatography ✔️Ans - Separate compounds of
interest
Qualitative
- To identify, or help to identify, a compound
Quantitative:
-How much of the substance is present
Define Chromatography ✔️Ans - Definition: Chromatography is a method of
analysis in which the flow of solvent or gas promotes the separation of
substances by differential migration from a narrow initial zone in a porous
absorptive medium.
What kind of struggle exists in chromatography ✔️Ans - Mobile phase
(Solvent or gas)
Stationary phase (tries to hold onto compounds)
Porous absorptive medium
How do the mobile and stationary phase work (describe attractions) ✔️Ans -
The mobile phase wants to move the compounds along rapidly, but the
stationary phase has a certain attraction for each compound. If these
attractions vary in strength from one compound to another, a separation of
the compounds can be achieved.
What are the subclasses of liquid chromatography ✔️Ans - Column L.C.:
Adsorption or Partition
HPLC (high pressure): Partition
"Flat":T.L.C. or Paper
Gel Filtration/ Gel Permeation: Adsorption
Ion Exchange
What are the subclasses of gaseous mobile phase chromatography ✔️Ans -
G.L.C.: Partition
