Seperation Techniques Flashcards
What are the 8 techniques to be made aware of
NMR Xray Diffraction Mass spectroscopy Thermal analysis Chromatography UV analysis Infrared IR analysis Microscopy
What is separation is affected by
differences in distribution
mobility of molecules
What are the 3 separation techniques to be made aware of
Electrophoresis
Membranous
Chromatography
What is gel electrophoresis
lab technique used to separate DNA or proteins based on size
How does gel electrophoresis work
Produce electrical field with cathode and anode on opposite ends of the box which contains the gel and the buffer.
The samples split forming a DNA ladder we then compare it to see what fragments mean what
What is membrane separation dependent on
size, the small molecules are removed down a concentration gradient hile the larger ones are left behind.
what is membrane separation used for
commonly used to remove impurities and small dye molecules from polymers or particles
What is chromatography
components of a mixture are separated based on differences in the rate at which they are carried through a stationary phase by a gaseous or liquid mobile phase
what is the stationary phase
fixed in place either in a column or on a planar surface
what is the mobile phase
moves or or through the stationary phase carrying with it the analyte mixture
What are the two types of High performance liquid chromatography
Normal phase
Reverse phase
what is normal phase
it is when there is a polar stationary phase and a non polar mobile phase
what is reverse phase
it is when there is a non polar stationary phase and a polar mobile phase
What is elution
process of washing sample components through the stationary phase by continuous flow of the mobile phase
how is retention time denoted
Tr
what are the factors that affect the tr
flow rate of mobile phase
and
composition of mobile and stationary phase
what is kc
Kc is termed the partition coefficient
it is the molar concentration of analyte in the stationary phase divided by the molar concentration of theanalyte in the mobile phase
What is the resolution
measure of how well peaks are seperated
what 3 factors affect band broadening
Path of them olecule through the column
Flow rate
Packing of the stationary phase
What are 3 factors that lead to misshapen peaks
longitudinal diffusion
resistance to mass transfer
eddy diffusion
What is longitudinal diffusion
analyte concentration higher at the Centre of the band so diffuses out to the edges
what affects longitudinal diffusion
slow flow rate increase longitudinal diffusion
what is Resistance to mass transfer
resistance to analyte movement
what is eddy diffusion
broadening of peaks due to different analytes taking different paths through to the stationary phase
What are the two main types of HPLC detectors
responsive to physical and chemical properties of sample components
responsive to changes in properties of the mobile phase
