Quiz Three Questions Flashcards
Define HPLC and UPLC. What is the difference between HPLC and UPLC?
HPLC is high pressure liquid chromatography. It can be used to separate a compound into its individual components based on differing polarities. UPLC is ultra high pressure liquid chromatography and it is also used to separate compounds. It is under even higher pressure which leads to quicker detection times and a higher resolution
What kinds of compounds elute first from the column in normal and reverse phase HPLC?
Normal: non polar compounds elute first because of the non polar mobile phase
Reverse: polar compounds elute first because of the polar mobile phase
Why do you need to degas the HPLC solvent?
It is important to degas the solvent because it gets rid of bubbles which will affect the flow rate and pressure - skewing results
What are the five principal components of HPLC?
The five principal components of HPLC are the pump, degasser, column, detector, and recorder
What are two applications of HPLC?
Two applications of HPLC are to calculate reseveratrol in wine and to test for adulteration in samples like grape juice
What is the difference between isocratic and gradient flow?
Isocratic: the ratio of polar to non polar components in the mobile phase remain the same the whole time through the column - slow elution
Gradient: the ratio of polar to non polar components in the mobile phase changes over time - quick elution (usually becomes more non polar in reverse phase)
