Abstract:Objective To modify the spherical nanometer calcium carbonate by polyethylene glycol (PEG) and sodium polyacrylate (PAAS), and analyze its effect on intestinal lead removal in vitro. Methods The spherical nanometer calcium carbonate was made by the method of compound decomposition, and it surface properties were modified by dispersant PEG and PAAS. The structural characteristics of the modified nanometer calcium carbonate were investigated by the analysis of particle size and zeta potential, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction method and infrared spectrum. The effect of lead removal from the simulated intestinal fluid in vitro was measured by atomic absorption spectrometer. Results The particle size, electric potential, dispersion and crystal stability of the modified nanometer calcium carbonate were the best when the ratio of PEG to PAAS was 1 : 1, and the lead ion concentration was reduced to below 30 μg/L in 4 h, with satisfactory effect of lead removal. The difference was significant compared with micron calcium carbonate (P < 0.05). Conclusions The calcium carbonate nanoparticles modified by PEG and PAAS are stable and non-toxic, and can be further made into oral preparation for removing lead from human intestinal tract.