What would be the effect on a chromatographic peak of introducing the sample at too slow a rate?

If the sample is injected at too slow a rate the chromatographic peak would become broad and the resolution would be lowered.

What is the retention factor in column chromatography?

However, in column chromatography, the retention factor or capacity factor (k) is defined as the ratio of time an analyte is retained in the stationary phase to the time it is retained in the mobile phase, which is inversely proportional to the retardation factor.

What are the effects of slow sample injection on a gas chromatogram?

A slow injection profile increases the band width of all solute peaks equally in terms of retention time as the solute mixture is slowly flushed from the injector volume onto the column. At least two remedies are possible for this degradation of efficiency, cold trapping and use of the solvent effect.

What is the effect of stationary phase film thickness on gas chromatograms?

Stationary phase film thickness (μm) directly affects retention, resolution, and elution temperature for each sample component. When changing either film thickness or the temperature program, you must reconfirm peak identifications as elution order changes can occur.

What affects retention time in chromatography?

A change in the temperature program often causes a retention time shift of all the peaks. A change in the initial temperature, the initial hold time, or the ramp rate can affect all of the peaks. Retention times increase with a lower initial temperature, longer initial hold time, or a slower ramp rate.

What is peak width in chromatography?

Peak width is the distance between points where lines tangent to the peak’s left and right inflection points intersect the baseline, and is calculated using equation (1). This also presents a problem if the peak is distorted, so that it has multiple inflection points.

What is peak in column chromatography?

The chromatographic peak—which is the sum of the two elution profiles—is shown by the solid black line. Example 12.1. In a chromatographic analysis of lemon oil a peak for limonene has a retention time of 8.36 min with a baseline width of 0.96 min.

How will a slow injection introduction onto the column effect the resolution?

For optimum column efficiency, the sample should not be too large, and should be introduced onto the column as a “plug” of vapour – slow injection of large samples causes band broadening and loss of resolution.

What is the effect of injecting volumes more than 2 μl?

If the injection volume is doubled from 1 to 2 μL, the peak size for only one compound doubles as expected. If the volume is increased to 3 μL, the results are worse.

How does film thickness affect gas chromatography?

The thickness of the layer determines the amount of the stationary phase that is present in the capillary. Retention is directly related to the amount of the stationary phase; thicker films equal more retention.

What is the effect of thickness of stationary phase and inner diameter of the column on resolution in gas chromatography?

Non-polar phases have higher capacities for non-polar analytes, and polar phases have higher capacities for polar analytes.