HPLC Training Question MCQ

1. What could be the possible causes of high- or low-pressure generation or blockage in an HPLC system?

• A. Wrong wavelength setting in the detector

• B. Column blockage or air bubble in pump line

• C. Poor lamp intensity

• D. Sample injection volume too low

2. 2. Refractive Index detector cannot be used with:

• A. Isocratic elution

• B. Gradient elution

• C. Non-polar solvents

• D. Polar analyses

3. What happens when the rear seal wash solution runs out or the rear seal becomes dry?

• A. Detector wavelength fluctuates

• B. Pump pistons may get damaged and cause leakage

• C. Retention time increases sharply

• D. Column temperature becomes unstable

4. Why is purging necessary before starting the HPLC system, and what may happen if it is not purged properly?

• A. To clean detector lamp

• B. To remove air bubbles from solvent lines; without purging pressure may fluctuate

• C. To dry the column

• D. To reset the software

5. 5. Column efficiency is expressed as:

• A. Theoretical plates (N)

• B. Retention factor (k)

• C. Resolution (Rs)

• D. Capacity factor

6. What are the possible causes of a highly noisy or drifting baseline in chromatograms?

• A. Detector lamp aging, air bubbles, or mobile phase contamination

• B. Column temperature stability

• C. Software autozero setting

• D. Using pure solvents

7. Which HPLC mode is most commonly used in pharmaceutical analysis?

• A. Normal phase HPLC

• B. Reverse phase HPLC

• C. Ion exchange chromatography

• D. Size exclusion chromatography

8. How can you identify and solve piston seal leakage problems in the HPLC pump module?

• A. Observe solvent dripping from column outlet

• B. Check for liquid leakage behind the piston and replace the seal

• C. Adjust detector wavelength

• D. Increase column oven temperature

9. Retention time shift may occur due to:

• A. Change in mobile phase composition

• B. Column temperature variation

• C. Flow rate changes

• D. All of the above

10. Reverse phase HPLC uses:

• A. Polar stationary phase, non-polar mobile phase

• B. Non-polar stationary phase, polar mobile phase

• C. Both stationary and mobile phases are polar

• D. Both stationary and mobile phases are non-polar