Analytical Separation Flashcards
These are useful when there is a significant difference in at least one of the chemical or physical properties between analyte and interferences
Separation techniques
What are the classification of separation techniques
(1) Basis of Separation
(2) Separation Technique/s
What are the various basis of separation
size
mass or density
complex formation
change in physical state
change in chemical state
partitioning between phases
separation techniques for size
filtration
dialysis
size-exclusion chromatography
What are the different separation techniques
filtration
dialysis
size-exclusion chromatography
centrifugation
masking
distillation
sublimation
recrystallization
precipitation
electrodeposition
volatilization
extraction
chromatography
separation technique for mass or density
centrifugation
separation technique for complex formation
masking
separation techniques for change in physical state
distillation
sublimation
recrystallization
separation techniques for change in chemical state
precipitation
electrodeposition
volatilization
separation techniques for partitioning between phases
extraction
chromatography
The substance that remains in the filter paper (ex. mud) is called
residue
The clear liquid or the substance collected after filtration is called
filtrate
it is the method of separating insoluble impurities or substances from a liquid
filtration
other term for seize exclusion chromatography
gel filtration chromatography or SEC
It is used for protein purification and separates molecules based on size
Size Exclusion Chromatography
Molecules are separated based on their size and are eluted in order of decreasing molecular weight
Size Exclusion Chromatography
Molecules are separated based on their size and are eluted in order of ________________________________
decreasing molecular weight
SEC Workflow (steps)
- Insert sample in column
- Proteins collect at the top of the column
- Proteins separate based on size
- Proteins exit from the largest to the smallest
Where is SEC useful?
- Desalting
- Fractionation
It is the movement of solute molecules from an area of higher concentration to an area of lower concentration
diffusion
It is the diffusion of solvent across a semipermeable membrane, the movement solvent molecules from a region of lower solute concentration to a region of higher solute concentration
osmosis
It is the process of separating molecules in solution by the difference in their rates of diffusion through a semipermeable membrane
dialysis
These three have importance in biological processes
Diffusion, Osmosis, and Dialysis
It is the process of separation of insoluble materials from a liquid when normal filtration does not work well
Centrifugation
It is based on size, shape, density of the particles, viscosity of the medium, and the speed of rotation
Centrifugation
centrifugation is based on:
size
shape
the density of the particles
viscosity of the medium
speed of rotation
Its principle is that when spun rapidly, the denser particles are forced to the bottom and the lighter particles stay at the top
Centrifugation
It is the apparatus used for centrifugation
Centrifuge
It is the centrifuge tube holder in a centrifuge
Rotor
It utilizes differences in solubility
extraction
It utilizes differences in polarity
chromatography
It utilizes differences in boiling points
distillation
Extraction utilizes differences in ______________
solubility
Chromatography utilizes difference in _______________
polarity
Distillation utilizes differences in _____________________
boiling points
Mixture of two ____________________ with very disparate boiling points
miscible liquids
The ________________ will cause the temperature inside the condenser to drop
cold water
The cold water will cause the temperature inside the condenser to drop, so when the vapor enters this section, it will ______________ back into a liquid
condense
After distillation, the condensed vapor is often called the
distillate
It refers to the liquid product that is collected after the vapor has been condensed and separated through the distillation process
distillate
It is useful for performing separations
distillation
It utilizes a fractionating column to separate mixtures with many components, like the atmosphere, or certain mixtures with industrial applications
Fractional distillation
It is useful for running reactions
distillation
It is a mixture of two or more liquids that when boiled, the vapor will contain those constituents in the same proportion as the liquid, and it will boil at a temperature lower than any of their individual boiling points
Azeotope
These are examples of such an azeotrope, where special techniques are needed for such mixtures
ethanol and water
Distillation Tips
- Make sure your distillation flask is not more than half full
- Make sure your thermometer is in the correct position
- Make sure your heat source is easy to remove very quickly
- Make sure everything is clamped and clipped
- You may collect distillate only at the desired temperature range
mixture of ammonium chloride and chalk powder can be separated by the method of
sublimation
It is the property of substance in which it is converted directly from solid to gas or vice versa
sublimation
substances converted directly from solid to gas or vice versa
sublime
Some example of solids which sublimes are
- ammonium chloride
- camphor
- naphthalene
- anthracene
one technique for the purification of solids
Recrystallization
It is used to solve when the lattice structure is forming during the precipitation, ions, and other particles that do not belong in the lattice will get trapped inside and disrupt the pattern of the lattice
Recrystallization
Recrystallization needs a solvent that offers:
- low solubility at room temp. (will recrystallize upon cooling)
- high solubility at high temp. (will dissolve upon heating)
- high solubility for the impurity at room temperature (stays dissolved)
- or low solubility for the impurity at high temp. (never dissolves)
It is a powerful process for the purification of solids
Recrystallization
Solvent selection may require trial and error needs
- polarity of the solvent
- tabulated solubility data
This will increase as a result of the recrystallization process
Purity
It can kick start crystallization
seed crystal
collect the crystals by _____________
filtration