Uptake and retention of amitriptyline by kaolinite

- AT uptake by kaolinite was relatively fast, suggesting surface adsorption instead of intercalation.
- Solution pH had minimal effect on AT uptake while increasing ionic strength reduced AT adsorption.
- Cation exchange was the dominant mechanism for amitriptyline (AT) uptake on kaolinite.
- Attachment of the tertiary amine on the kaolinite surfaces restricted its IR vibration.