TLC and HPLC

What is HPLC?

• A technique to separate components based on pH

• A technique to separate components based on polarity

• A technique to separate components based on liquidity

• A technique to separate components based on temperatue

What is the function of degasser?

• To add gas into the system of HPLC

• To prevent gas into the system of HPLC

• To change liquid into gas

• To change gas into liquid

Which substance is used in normal phased HPLC?

• stationary phase: high polar

  mobile phase: low polar

• Stationary phase: high polar

  Mobile phase: high polar

• Stationary phase: low polar

  Mobile phase: low polar

• Stationary phase: low polar

  Mobile phase: high polar

Solid phase extraction is used to ...

• purify the samples from unwanted components

• purify the solvents from unwanted components

• purify the samples using low elution strength

• purify the samples using high elution strength

Water / methanol is used as a mobile phase in ...

• Normal phase of HPLC

• Reverse phase of HPLC

What happens to the given substance under reverse phase conditions when the pH of the mobile phase is raised?

• Retention time doesn't change

• Retention time will increase

• Retention time will decrease

What is the most commonly used stationary phase in reversed phase chromatography?

• C18

• Silicagel

• C8

• Carbon

HPLC methods include

• liquid/liquid (partition) chromatography

• liquid/solid (adsorption) chromatography

• ion exchange nd size exclusion chromatography

• all of the option correct

In order to compare to chromatograms what must be kept the same?

• stationary  phase
• mobile phase
• temperature
• all of the above

Based on a normal chromatography, the stationary phase is polar.

• TRUE

• FALSE

• Depends on the substance