Chromatography Quiz

What is the main purpose of chromatography?

• To separate and quantify target samples in a mixed sample

• To mix samples

• To measure the weight of samples

• To analyze samples under a microscope

Answer explanation

Chromatography's main purpose is to separate and quantify target samples in a mixed sample, making it the correct choice.

What is the stationary phase in chromatography?

• The phase that reacts with the analyte

• The solid or liquid phase that is fixed in place

• The phase that carries the mixture through the stationary phase

• The phase that moves over or through an immobilized phase

Answer explanation

The stationary phase in chromatography refers to the solid or liquid phase that is fixed in place, allowing for separation of components.

What does retention time in chromatography refer to?

• The time for the mobile phase to reach the detector

• The time required for sample preparation

• The time for the analyte to pass through the column

• The time for the analyte to mix with the solvent

Answer explanation

Retention time in chromatography refers to the time for the analyte to pass through the column.

Which method is used for quantitative analysis in chromatography based on peak height?

• Internal Standard Method

• Area Normalization Method

• Calibration method

• Response Factor Method

Answer explanation

The Area Normalization Method is used for quantitative analysis in chromatography based on peak height by comparing the peak heights of different compounds to a reference standard.

What is the purpose of the dead time in chromatography?

• To measure the time a non-retained compound spends in the stationary phase

• To determine the number of theoretical plates

• To calculate the retention factor

• To adjust the retention time

Answer explanation

The dead time in chromatography is used to measure the time a non-retained compound spends in the stationary phase, allowing for accurate analysis of the separation process.

What is the selectivity factor in chromatography?

• The ratio of the capacity factors of two peaks

• The time for the analyte to pass through the column

• The time a compound spends in the stationary phase

• The measure of how well species have been separated

Answer explanation

The selectivity factor in chromatography is defined as the ratio of the capacity factors of two peaks, making it the correct choice.

Which chromatographic method is based on the relative solubility of analyte in mobile and stationary phases?

• Size Exclusion Chromatography

• Ion Exchange Chromatography

• Adsorption Chromatography

• Partition Chromatography

Answer explanation

Partition Chromatography is based on the relative solubility of analyte in mobile and stationary phases, making it the correct choice.

What is the efficiency of a chromatographic column expressed as?

• Number of solvents used in the mobile phase

• Number of peaks in the chromatogram

• Number of compounds that can be separated by the column

• Number of theoretical plates or height equivalent to a theoretical plate

Answer explanation

The efficiency of a chromatographic column is expressed as the number of theoretical plates or height equivalent to a theoretical plate.

What is the effect of column diameter on column efficiency?

• Increases the efficiency

• Has no effect on efficiency

• Increases the retention time

• Decreases the efficiency

Answer explanation

The correct answer is 'Decreases the efficiency' because as the column diameter increases, the efficiency of the column decreases due to reduced interaction between the sample components and the stationary phase.

How is the resolution between two peaks calculated in chromatography?

• By measuring the peak width at the base of the peaks

• By calculating the retention time of the peaks

• By determining the number of theoretical plates

• By analyzing the dead time of the peaks

Answer explanation

The resolution between two peaks in chromatography is calculated by measuring the peak width at the base of the peaks.