Chromatography Notes

Relevant Techniques in JF Pharm

• TLC (and HPTLC)
• Column Chromatography
• GC
• HPLC

Technique Classification

The chromatographic technique used is dependent on the combination of phases in use.

liquid-solid, gas-liquid etc.

Types of Molecular Interactions Causing Change in Affinity

• Dipole-dipole
• Ion-Induced Dipole
• Hydrogen Bonds
• Coulombic
• Dispersive

Mobile Phases

Normal phase uses water as a base

Reverse-phase uses organic solvents as the base

Usually pick solvents which are non-toxic, cost-efficient and that do not degrade on storage. Such examples are…

1. Methanol
2. Ethanol
3. TFA
4. Acetonitrile
5. Formic Acid
6. Isopropyl alcohol.

among many others.

Stationary Phase Types

Many silica based, having amphiphilicity, with a polar head and non-polar tail.

Types of stationary phases include

• Alumina
• Silica
• Modified Silica

Types of setups for these include

• Reverse — Most common
• Normal
• Ion-exchange
• Ion Pair
• Size Exclusion — Pores

Functional Groups in Order of lipophilicity.

1. Alkanes
2. Alkenes
3. Aryl Halides
4. Sulphides
5. Ethers
6. Aldehyde/Ketone/Esters
7. Nitros
8. Amides
9. Sulphones
10. Sulphoxides

Indicators of Note

Ninhydrin — Amines turn reddish pink

Dragendorff — Alkaloids turn orange

Vanillin — Steroids, terpenes and sugars turn blue-black

UV light used for conjugated compounds — Compounds with high degrees of aromaticity.