Question

In: Chemistry

Describe why different materials have different elution rates through a stationary phase and list the three...

Describe why different materials have different elution rates through a stationary phase and list the three main factors that govern how fast a chemical will elute through a column.

Solutions

Expert Solution

>> In chromatography, the separation of different materials depends on the differences in polarity between the eluting compounds and the stationary phase.

>> The polar stationary phase adsorbs more polar compounds. It is retained by more by the stationary phase.

>> The non-polar stationary phase adsorbs more by the non-polar molecules.

>> The selection of the mobile phase is also equally important. The good separation of the molecules is achieved by using fairly polar stationary phase and low polarity mobile phase.

>> Silica gel and alumina are the very good stationary phases. Alumina is a polar adsorbent and is used for the separation of polar compounds. Silica gel is less polar than Alumina. Carbon is the non-polar adsorbent.

Factors affecting the elution of the chemical through the column:

>> The polarity of the mobile phase (solvent)

>> Interaction of the different molecules with the stationary phase

>> Separation of the different materials depends on the particle size of the adsorbent.


Related Solutions

Describe the three parts of a specification and list the different methods of specifying construction materials:...
Describe the three parts of a specification and list the different methods of specifying construction materials: I II III
Which phase carries the analyte through the Chromatographic separation? Standard Phase, Detection Phase ,Injection Phase, Stationary...
Which phase carries the analyte through the Chromatographic separation? Standard Phase, Detection Phase ,Injection Phase, Stationary Phase, Mobile Phase Which phase slows the analyte down in the Chromatographic separation? Standard Phase, Detection Phase ,Injection Phase, Stationary Phase , Mobile Phase If you increase the flow rate of the mobile phase, will the analyte come out ________? Slower, In two Peaks, Faster, Unchanged In this separation the stationary phase is polar and the mobile phase is non-polar. Youre separating two molecules,...
A compound is "sticky" with respect to the silica stationary phase. Why is that?
A compound is "sticky" with respect to the silica stationary phase. Why is that?
why do different kind of bonds have different levels of interest rates? why do interest rates...
why do different kind of bonds have different levels of interest rates? why do interest rates increase and decrease over time? describe in detail the yeild curve and the expectation hypothesis.what does the yeild curve look like in the current economic environment ? if the yeild curve is steep, how would that affect your borrowing and investing decisions? need it ASAP
list three ways in which older washing machines used different materials in their construction that their...
list three ways in which older washing machines used different materials in their construction that their more modern counterparts
Discuss why different elution solvents are often used in the column chromatography. In what order and...
Discuss why different elution solvents are often used in the column chromatography. In what order and why should the elution solvents be used? In this experiment would the separation happen if only 10:90 ethyl acetate/hexanes was used as an eluting solvent? Would the separation happen if 20:80 ethyl acetate/hexanes was used first followed by 10:90 ethyl acetate/hexanes? I need at least a paragraph response to this!
) List five different advantages of composite materials over conventional materials.
) List five different advantages of composite materials over conventional materials.
Describe three different families of soultion curves. You should describe how they are different and why...
Describe three different families of soultion curves. You should describe how they are different and why this makes sense based on their initial condition.
Q13) Please explain why different countries around the world have developed at different rates?
Q13) Please explain why different countries around the world have developed at different rates?
In this experiment column chromatography, two different elution solvent systems were used. Why? If their order...
In this experiment column chromatography, two different elution solvent systems were used. Why? If their order had been reversed (i.e., 20:80 EtOAc–Hex was used first), how would the separation of the fractions have changed?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT