High Pressure Liquid Chromatography Questions & Answers
1. Which of the following is not true about High-pressure liquid chromatography (HPLC)?
a) It requires high pressure for the separation of the specious
b) There is no need to vaporize the samples
c) It is performed in columns
d) It has high sensitivity
Answer: b
Explanation: In High-pressure liquid chromatography (HPLC), samples need to be vaporized. It has high sensitivity.
2. High-pressure liquid chromatography can be performed only in columns.
a) True
b) False
Answer: a
Explanation: High-pressure liquid chromatography can be performed only in columns. This is because application of high pressure in open bed will not be effective.
3. Which of the following is not an advantage of Syringe type pumps used in High-pressure liquid chromatography?
a) Independent of viscosity
b) Pulse-less flow
c) High-pressure capability
d) Unlimited solvent capacity
Answer: d
Explanation: The limitation of Syringe type pump is that it has the limited solvent capacity and is inconvenient when solvents are to be changed.
4. Which of the following is not true about solvent programming which is done in high-performance liquid chromatography?
a) It provides unequal bandwidths
b) It provides fast overall separation
c) It provides maximum resolution
d) It provides maximum sensitivity
Answer: a
Explanation: Solvent programming is done to provide equal bandwidths. It provides maximum sensitivity for every solute in the sample.
5. Which of the following pulse damper takes up some amount of the pulsation energy which is released to provide smooth pressure without pulsations?
a) Flexible bellows or compressible gas passed through tee columns
b) Flexible inert diaphragm
c) Electronic pulse damper
d) Electrical pulse damper
Answer: a
Explanation: Flexible bellows or compressible gas passed through tee columns take up some of the pulsation energy which is released to provide smooth pressure without pulsations. Its main purpose is to avoid pulses.
6. Which of the following is not a characteristic of the syringe pump used in high-pressure liquid chromatography?
a) Pressure capability is high
b) Maintenance is frequent
c) Limited reservoir capability
d) Slight change of flow rate when extremely high pressure compresses the solvent
Answer: b
Explanation: In syringe pumps, maintenance is infrequent. However, it has high pressure capability.
7. Syringe pumps used in High-pressure liquid chromatography are most suitable for which of the following columns?
a) Capillary columns
b) Guard columns
c) Short-fast columns
d) Small bore columns
View Answer
8. Gravity feed method for solvent delivery is not used with narrow bore columns packed with fine mesh particles.
a) True
b) False
Answer: a
Explanation: Gravity feed method for solvent delivery is not used with narrow bore columns packed with fine mesh particles. This is because they cannot deliver solvent at high pressure.
9. Which of the following cannot be done to reduce ripple in High-pressure liquid chromatography?
a) Using bellows
b) Using restrictors
c) Using long nylon tube between pump and column
d) Avoiding the use of solvent pump
Answer: d
Explanation: Solvent pumps have to be used to reduce pulses in the solvent flow. When there is a pulsed flow, the efficiency of column decreases.
10. Which of the following is not true about Hydraulic capacitance flow control system used in HPLC?
a) It can be used only for liquids with low viscosity
b) It is irrespective of solvent compressibility
c) It maintains constant flow
d) It smoothens high-pressure pump pulsations
Answer: a
Explanation: Hydraulic capacitance flow control system used in HPLC is irrespective of the solvent viscosity. It is also irrespective of the solvent compressibility.
