1. Column and mobile phase types for basic drugs
Derivatization of silica to obtain reversed phase columns

2. Column and mobile phase types for basic drugs
The derivatization is not complete because of the complex structure of the silica
and the steric hindrance of the alkyl groups.
Leading to  underivatised silanols

3. Column and mobile phase types for basic drugs
Free silanol group gives uncontrollable interaction with the basic compounds

4. Column and mobile phase types for basic drugs

5. Column and mobile phase types for basic drugs

6. Column and mobile phase types for basic drugs

7. Column and mobile phase types for basic drugs

8. Column and mobile phase types for basic drugs
Mobile phase can affect the characteristics of the column

9. Column and mobile phase types for basic drugs
Mobile phase can affect the characteristics of the column

10. Column and mobile phase types for basic drugs
Ion pairing agent at low concentrations

11. Column and mobile phase types for basic drugs
Ion pairing agent at high concentrations

12. Column and mobile phase types for basic drugs
Embedded group technology

13. Column and mobile phase types for basic drugs

14. Column and mobile phase types for basic drugs

15. Column and mobile phase types for basic drugs

16. Column and mobile phase types for basic drugs

17. Column and mobile phase types for basic drugs
Poly derivatization

18. Column and mobile phase types for basic drugs