Final/ Exam 2 (E6-E10) Flashcards
E6
What is flow injection analysis (FIA)
FIA is a non robotic automated system that handles sample preparation and injection into an instrument
E6
What is one advantage and disadvantage of FIA?
advantage: reduces error from manual methods or degredation of sample due to time
disadvantage: dispersion/ dilution of the sample from injection to detection
E6
Dispersion
= concetrantion of sample at detector/concentration of og sample
E6
What is High-performance liquid chromatogarphy/ HPLC
HPLC is a form of liquid chromatography to separate samples
for temperature senstive and biochemical species (species not for GC)
E6
Adsorption
occur when the sample is more attracted to the stationary phase
E6
Partition
if the sample is more attracted to the mobile phase
E6
Reverse Phase chromatography
non polar stationary phase + polar mobile phase
- partition separation
- non polar compounds retained longer
E6
Normal Phase chromatography
polar stationary phase + non polar mobile phase
- adsorption separation
- polar compounds retained longer
E6
Hildebrand solubility parameter
measures how much energy is required to pull two solvent molecules apart
- the higher the value the more polar the molecule
E6
In experiment E6 was the red or blue dye more polar? Why?
The red dye was more polar
- eluted first
- had less fractions
- structure has less non polar groups present
E6
Ion pair chromatography
- acidic, basic, or amphoteric compounds to be separated
- counter ion is added to mobile phase to pair with ion in solution (can increase or decrease interactions depending on polarity of stationary phase)
E6
the more — the ion pairing agent, the greater the retention time of the ion pairing compound
hydrophobic/non polar
E6
When a solute passes through a column for chromatography it establishes – — with the mobile phase and stationary phase
an equilibrium
- by considering it an equilbrium we are able to establish analytical equations
- mass transfer
E6
What are theoretical plates and why do we want to minimize their height?
theoretical plates are where an equilibrium between a solute and stationary phase and mobile phase is established
- the height must be minimized so the number of theoretical plates can be maximized and column efficency improves
- N= L/H
E6
Size exclusion chromatography
- separates a sample on its ability to move between the pores of a stationary phase
- large species elute first
- useful for assesing native vs denatured protein
- polymer vs monomer samples
