HPLC

Question 1

What is the MP reservoir?

Answer 1

holds the solvent

solvent is delivered through teflon tubing called the inlet line

Question 2

What is purpose of the sinker frit or push filter?

Answer 2

prevent any dust or particulate matter from entering the pump

Question 3

Why is He degassing of MP required?

Answer 3

presence of oxygen in mobile phase causes bubble formation resulting in air in the flow system and pump pressure will change causing a spike in the chromatogram.

Question 4

What does the pump consist of?

Answer 4

check valves
pulse dampener
pressure transducer
flow controller

Question 5

What do the check valves do?

Answer 5

draws liquid in and out of the solvent chamber

Question 6

What is the pulse dampener?

Answer 6

prevent pulses in the baseline created by pump strokes

Question 7

What is the pressure transducer?

Answer 7

monitor the pressure of the liquid flow

Question 8

What is the flow controller?

Answer 8

controls the liquid flow rate

Question 9

Titanium pump has ____ degree of inertness and is useful for ____ analysis.

Answer 9

greater, biomolecule

Question 10

What are PEEK and Teflon pumps useful for?

Answer 10

corrosive solutions (HCl) are used as MP
separation of metals

Question 11

What is mircobore?

Answer 11

diameter up to 2mm

Question 12

What is standard bore?

Answer 12

2-12mm diameter
most commonly used
100um/min - 10mL/min FR

Question 13

What is preparative column?

Answer 13

> 10mL/min

requires special pump

Question 14

What is the double piston pump?

Answer 14

two pistons driven in opposite directions
1st draws solvent in
2nd draws solvent out

Question 15

What is the advantage of the double piston pump?

Answer 15

minimizes pulsations

Question 16

What are the two manually operated injectors?

Answer 16

septum mode

valve injection

Question 17

What does the valve injector do?

Answer 17

allows reproducible introduction of sample into the pressurized MP without interruption of flow even at high temperature

Question 18

What is the flow direction in the load position?

Answer 18

MP bypasses sample loop and flows straight from pump into column

Question 19

What is the flow direction in the inject position?

Answer 19

sample is introduced into system

MP passes from pump into sample loop into column

Question 20

What are the benefits of the autoinjector?

Answer 20

wide variability in injection volume (0.1uL - 2 mL)
precision is better than or equal to manual injection
high sample throughput and less labor intensive