RESUMEN
Objective To study the capacity of dentifrice containing hydroxyapatite (HA) particles with various grain sizes on the sorption of Cu (Ⅱ) ion from aqueous solution. Methods Three groups of dentifrice suspensions containing 3% HA particles with 60 nm grain size, 3% HA particles with 12 μm grain size, and blank dentifrice were prepared with serial concentrations. Copper ion solutions with initial concentration of 4.0 mg/L were mixed with dentifrice suspensions respectively and then been kept still for 24 hours. The residual copper ion concentration of the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of copper ion was calculated. Results The residual copper ion concentration of the supernatant decreased with increase of the concentration of dentifrice suspensions. The sorption rate of copper ion of dentifrice containing 60 nm HA was highest among the three groups. Conclusion Nano HA should be added into dentifrice to enhance the sorption capacity of copper ion from aqueous solution.