explain in detail each question 1) Why are we adjusting the pH of our sample? Wh

Question

explain in detail each question

1) Why are we adjusting the pH of our sample? Why is a basic pH necessary?
2)What is the difference between the ionized and un-ionized drugs? Which is most
important for our extraction?
3) Why is it important to evaporate the organic layer at low heat?
4)) How is Rf value calculated?
5)) What are the key features of an efficient solvent system?
6) Why are we using the two different systems? Ethyl Acetate: methanol: ammonia (82:13:5) and then system Ethyl Acetate: Methanol (98:2) explain each system and polarities and properties and how each system works

7)) What is the purpose of the chosen spraying reagents?

Explanation / Answer

Solubility of some compounds in particular solvent depends on the PH. So adjustment of the PH is crucial to dissolve the compound completely in the organic solvent using for extraction . When we analyse basic compounds basic PH is necessary.

There are cases where acidc PH cause degradation of the products. So PH adjustment is important.

2. What is the difference between the ionized and un-ionized drugs? Which is most important for our extraction?

Ionised portion of drugs are charged. It attracts water molecules and form complexes. Ionised drugs are less lipid soluble and unionized drugs are more lipid soluble that is they have better absorption . The unionized drugs are more important for extraction.

3. Why is it important to evaporate the organic layer at low heat?

The low heat prevents the evaporation of organic solvents using for extraction. Some times more heat will make highly volatile products to escape. So less heat is always preferable

4. How is Rf value calculated?

Rf is defined as the ratio of the distance traveled by a spot (measured from the center of the spot) to the distance traveled by the solvent.

Rf= Distance travelled by compound/ Distance travelled by solvent

5. What are the key features of an efficient solvent system?

Efficient solvent system will give good separation between the product spot and impurity spots

6. Why are we using the two different systems?  Ethyl Acetate: methanol: ammonia (82:13:5) and then system Ethyl Acetate: Methanol (98:2) explain each system and polarities and properties and how each system works?.

When we use two different systems we will get two different results and can compare which gave the best separation.

Ethyl Acetate: Methanol (98:2)

This solvent system consists of 98 ml of Ethyl acetate and 2 ml of methanol . it is less polar compared to Ethyl Acetate: methanol: ammonia (82:13:5) system.

7. What is the purpose of the chosen spraying reagents?

The spraying agents will react with ions on the TLC plates and develop colors .This help us to identifythe spots on the TLC plate

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.