In TLC, why do you spot multiple times? Select one or more correct answers.
A. To fill the capillary almost instantly by capillary action.
B. So the developing chamber solvent does not evaporate.
C. The higher compound concentration facilitates visualization.
D. To acheive a high concentration of sample in a small spot.
Isn't D the choice? Are capillaries involved in TLC? Then A can't be right.
There is more than one answer for this problem.
To determine the correct answer, let's analyze each option:
A. To fill the capillary almost instantly by capillary action.
This option is incorrect because spotting multiple times does not affect the filling of the capillary. Capillary action occurs naturally and is not influenced by how many times you spot the TLC plate.
B. So the developing chamber solvent does not evaporate.
This option is also incorrect. Spotting multiple times does not have an impact on the evaporation of the developing chamber solvent. Evaporation is determined by various factors such as temperature, humidity, and the surface area of the solvent exposed to the air.
C. The higher compound concentration facilitates visualization.
This option is correct. When you spot a compound multiple times in the same spot, it increases the concentration of the compound on the TLC plate. This higher concentration can make it easier to visualize the compound after the TLC plate is developed.
D. To achieve a high concentration of the sample in a small spot.
This option is incorrect. Spotting multiple times does not necessarily achieve a higher concentration of the sample in a small spot. The concentration of the sample is primarily dependent on the amount of sample that is spotted, not the number of times it is spotted.
Therefore, the correct answer is:
C. The higher compound concentration facilitates visualization.