CHAPTER 6 HPLC

What is the primary purpose of HPLC (High Performance Liquid Chromatography)?

• To separate the components of a vaporized sample

• To separate the components of a mixture in a liquid phase

• To vaporize components for analysis

• To detect the components in a gaseous mixture

What makes HPLC different from other liquid chromatography techniques?

• Use of high pressure

• Use of a solid stationary phase

• Use of an organic mobile phase

• Use of a gaseous mobile phase

Which of the following is NOT a component of an HPLC system?

• Mobile phase reservoir

• High pressure pump

• Gas detector

• Chromatographic column

What is the purpose of the high-pressure pump in an HPLC system?

• To heat the mobile phase

• To mix the sample with the mobile phase

• To force the mobile phase through the column

• To filter the mobile phase

Which of the following is a characteristic of an ideal mobile phase for HPLC?

• High viscosity

• Chemically reactive

• Low viscosity

• Non-volatile

What is the purpose of sparging in HPLC?

• To add a buffer to the mobile phase

• To remove dissolved air bubbles in the mobile phase

• To mix the solvents in the mobile phase

• To cool the sample before injection

In HPLC, which of the following elution techniques maintains a constant mobile phase composition throughout the separation?

• Isocratic elution

• Gradient elution

• Pulsed elution

• Temperature-programmed elution

Which elution technique involves changing the mobile phase composition during the separation process?

• Isocratic elution

• Gradient elution

• Temperature-programmed elution

• Continuous elution

What is the typical flow rate range of the pump in analytical HPLC?

• 0.1-1 ml/min

• 1-10 ml/min

• 10-50 ml/min

• 50-100 ml/min

What is the main advantage of using gradient elution in HPLC?

• Faster separation of all components

• Improved resolution and shorter analysis time

• Simpler instrumentation

• Lower cost