Chromatographic Techniques Quiz

What is the mobile phase in liquid chromatography?

• Plasma

• Liquid

• Solid

• Gas

Answer explanation

The mobile phase in liquid chromatography is a liquid, which is used to carry the sample through the stationary phase for separation.

What determines the separation in liquid chromatography?

• Temperature

• Density

• Mobilities

• Pressure

Answer explanation

Mobilities determine the separation in liquid chromatography by influencing the movement of different compounds through the stationary phase.

Which technique is used for the separation of solid-liquid substances?

• Solubility

• Partition

• Absorption

• Adsorption

Answer explanation

The technique used for the separation of solid-liquid substances is Adsorption.

What is the elution order when separating beta carotene and ascorbic acid?

• Simultaneous elution

• Beta carotene eluted first, then ascorbic acid

• No elution

• Ascorbic acid eluted first, then beta carotene

Answer explanation

When separating beta carotene and ascorbic acid, ascorbic acid eluted first, followed by beta carotene.

In reversed-phase chromatography, what type of stationary phase is commonly used?

• Ionic

• Hydrophobic

• Non-polar

• Polar

Answer explanation

In reversed-phase chromatography, a non-polar stationary phase is commonly used to separate compounds based on their hydrophobicity.

What is the most popular type of reversed-phase HPLC packing?

• Silica

• Alumina

• C18-bonded silica

• Octyl (C8) groups

Answer explanation

The most popular type of reversed-phase HPLC packing is C18-bonded silica.

In normal-phase chromatography, what is the nature of the stationary phase?

• Non-polar

• Polar

• Hydrophobic

• Ionic

Answer explanation

In normal-phase chromatography, the nature of the stationary phase is polar, allowing for separation based on polarity differences with the mobile phase.

What is the elution order in normal-phase chromatography for a black three-dye mixture?

• No elution

• Simultaneous elution

• Blue dye eluted first, then yellow dye

• Yellow dye eluted first, then blue dye

Answer explanation

In normal-phase chromatography, the elution order for a black three-dye mixture is typically blue dye eluting first, followed by the yellow dye.

What is the main purpose of chromatography?

• To destroy chemical substances

• To separate a mixture into individual components

• To mix different chemicals

• To measure temperature changes

Answer explanation

The main purpose of chromatography is to separate a mixture into individual components, not to destroy or mix chemicals or measure temperature changes.

Which property determines the retention time in normal-phase chromatography?

• Temperature

• Density

• Pressure

• Polarity

Answer explanation

Polarity is the property that determines the retention time in normal-phase chromatography by influencing the interactions between the analyte and the stationary phase.