Adsorptive elimination of paracetamol from physiological solutions: Interaction with MFI-type zeolite

Abstract

Paracetamol (acetaminophen (ATP)) at toxic concentrations to human is successfully adsorbed onto MFI-type zeolite ZSM-5 (Si/Al = 30) stepwise under conditions approaching human serum composition. While the speed of adsorption in physiological serum at 37 °C is fast enough to be accomplished in a 4 h standard dialysis session, maximum adsorption levels at equilibrium concentration is reduced when the solution becomes more complex. In pure water, at the highest equilibrium concentrations, the adsorption is almost doubled. Thermogravimetric measurements confirm paracetamol adsorption inside the micropores. Rietveld-analysis on powder X-ray diffraction data proves that after adsorption, paracetamol is located at the intersection of the straight and zigzag channel of the ZSM-5 zeolite. 1H MAS NMR experiments performed on ZSM-5 zeolite after paracetamol adsorption confirm the absence of interaction between paracetamol molecules and water molecules and/or between the paracetamol molecules themselves. In conclusion, elimination of paracetamol at toxic concentrations in human serum (by ultrafiltration of blood) is a smart way to eliminate selectively such a molecule by physisorption without further interference onto other biochemical equilibria.