Question

In: Chemistry

Briefly describe the effect of the following procedural errors on a thin-layer chromatogram. Applying too large...


Briefly describe the effect of the following procedural errors on a thin-layer chromatogram.

a) Applying TOO LARGE a sample when spotting the plate.

b) Placing the spotted plate into a developing chamber containing an eluent level ABOVE the level of the origin.

c) Allowing the plate to remain in the developing chamber until the eluent front reaches the TOP of the plate.

d) Removing the plate from the developing chamber when the eluent front has move only HALF-WAY up the plate.

e) Developing the plate in an UNCOVERED chamber.


Solutions

Expert Solution

a) Applying TOO LARGE a sample when spotting the plate.

if you have too much sample in the spot you will have your spots with a long tail (Tailing) which dont let you know the exact Rf value of each compounds.

Tailing occurs because Non-adsorbed solute will migrate through the stationary phase faster than expected, a phenomenon, the substance trails a line behind it like a tail.

b) Placing the spotted plate into a developing chamber containing an eluent levelABOVE the level of the origin.

the compounds will disolve in the eluents before start the "running" in the TLC.

c) Allowing the plate to remain in the developing chamber until the eluent front reaches

     the TOP of the plate.

if you wait to long after the eluent reach the top of the plate your compouns will mix again in the top of the TLC plate.

d) Removing the plate from the developing chamber when the eluent front has moveonly HALF-WAY up the plate.

If you remove the TLC plate before reaching the top of the plate, you will not have a good separation and you cannot calculate the RF value.

e) Developing the plate in an UNCOVERED chamber.

The solvent will evaporate, if you use as eluent a mixture of solvents, the most volatile solvent will evaporate and the eluente will have a diferente polarity than what you expected


Related Solutions

What compound will you need to use to visualize the amino acids on thin layer chromatogram?...
What compound will you need to use to visualize the amino acids on thin layer chromatogram? A student seperates a mixture of octane and 1-octanol using thin layer chromotography. Which compound will move faster with tolunce. Give reason. You are a chemist working in a lab who is analyzing polar samples with thin layer chromatography. What type of solvent do you think would be ideal for your tests? Why?
briefly describe the theory of gas chromatography and the function of a basic gas chromatogram?
briefly describe the theory of gas chromatography and the function of a basic gas chromatogram?
Briefly explain the possible effect of the following experimental errors. TLC plate procedure with drug concentration....
Briefly explain the possible effect of the following experimental errors. TLC plate procedure with drug concentration. 1. You used a 1:200 ratio of ethyl acetate/acetic acid rather than 200:1: (Note: ethyl acetate is significantly less polar than acetic acid) 
2. You allowed the TLC plate to develop too long (past the point where the solvent reaches the top of the plate). 3. You used a plastic pipet rather than a thin glass spotter. 4. You labeled your plate using a...
describe and explain the possible effect on your results of the following experimental errors or vibrations....
describe and explain the possible effect on your results of the following experimental errors or vibrations. In each case, specify the component(s) whose percentage(s) would be too high or too low if: a.)After adding DCM to Panacetin, you didnt stir the mixture long enough. b.) during the NaOH extraction you failed to mix the aqueous and organic layers thoroughly c.)you mistakenly extracted the DCM solution with 1M HCL rather than 1M NaOH. d) instead of using pH paper, you acidify...
Describe and explain the possible effect on your TLC results of the following experimental errors or...
Describe and explain the possible effect on your TLC results of the following experimental errors or variations: a) The analyte spots are too large (b) The analyte solution is too dilute.
please briefly describe the three layer model of penetration studies
please briefly describe the three layer model of penetration studies
Briefly explain the steps that are involved in DNA replication. And Briefly describe how errors in...
Briefly explain the steps that are involved in DNA replication. And Briefly describe how errors in DNA replication are corrected.
describe the process whereby iodine visualizes otherwise invisible components of a developed thin layer plate
describe the process whereby iodine visualizes otherwise invisible components of a developed thin layer plate
List and briefly describe the errors that may occur with pH measurement
List and briefly describe the errors that may occur with pH measurement
Fully explain the following types of regulations and their legal effect: Legislative Interpretive Procedural As pertains...
Fully explain the following types of regulations and their legal effect: Legislative Interpretive Procedural As pertains to the Internal Revenue Code
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT