Separation and identification of Organic drugs

Question 1

Separation Involve?

Answer 1

Solvent Extraction
- Chromatograpy (separating molecules)
– HPLC, Gas Chromatography, Mass Spectrometry, Thin layer chromatography - Spectroscopy (UV, IR, NMR)

Question 2

Partition Coefficient & Fraction remaining in water

Solvent Extraction

Answer 2

Partition Coefficient:
- K=C1/C2 = g compound per mL organic solvent /g compound per mL water

Fraction remaining in water:
- Final mass of solute/Initial mass of solute = (V2/V2+V1K)^n
– V1 = volume of organic solvent in each extraction
– V2 = original volume of water
– n = Number of extraction
– K = Disruvution coeffcient

Question 3

Is multiple extraction better or one extraction?

Answer 3

Multiple extraction is better to get more % of the compound

Question 4

pH effect

Seperation

Answer 4

• Neutral species are more soluble in organic solvent.
• Charged species are more soluble in aqueous solution

To extract an acid into water
- pH needs to be higher than pKa

To extract a base into water
- pH needs to be lower than pKa