Analytical Chemistry: Chromatography

Which of the following is NOT a detector used with HPLC?

• ultraviolet detector

• thermal conductivity detector

• electrochemical detector

• evaporative light-scattering detector

• refractive index detector

Reversed-phase chromatography refers to which of the following?

• A nonpolar stationary phase and a nonpolar mobile phase

• A stationary phase and mobile phase of similar polarities

• A polar stationary phase and a polar mobile phase

• A polar stationary phase and a nonpolar mobile phase

• A nonpolar stationary phase and a polar mobile phase

What impact does the pH of the mobile phase have on the ability of a strongly acidic exchanger to interact with ions?

• decreases the ability to interact with ions as pH decreases

• decreases the ability to interact with ions as pH increases

• increases the ability to interact with ions as pH increases

• has no impact on the ability to interact with ions

• increases the ability to interact with ions as pH decreases

Which of the following is the ratio of length of column packing to retention time?

• Average linear rate of mobile migration

• Relative migration rate

• Selectivity factor

• Average linear rate of solute migration

___ is a plot of detector response versus retention time.

• Electrophoretogram

• Chromatogram

• Chromospectrum

• Spectrum

• Elution response

Normal-phase chromatography refers to which of the following?

• A nonpolar stationary phase and a polar mobile phase

• A polar stationary phase and a nonpolar mobile phase

• A nonpolar stationary phase and a nonpolar mobile phase

• A polar stationary phase and a polar mobile phase

• A stationary phase and mobile phase of similar polarities

Given below is a diagram of separation of two components of a mixture in a chromatographic column. From the diagram, infer which component has lesser affinity to the stationary phase.

• W

• X

• Y

• Z

In size exclusion chromatography, what happens to the larger particles?

• They are broken down into smaller particles.

• They bind permanently to the stationary phase.

• They elude first, before smaller particles.

• They remain on the column longer than smaller particles.

• They become oxidized as they move through the column.

What is the most common support material for a packed GC column?

• Glass

• Fused silica

• Diatomaceous earth

• Silica gel

• Alumina

Which of the following is defined as the ratio of moles of solute in stationary phase to the moles of solute in mobile phase?

• Total porosity

• Distribution constant

• Volumetric phase ratio

• Retention factor