In this study, the binding capacity of calcium ions of sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), trisodium citrate (TSC), and potassium oxalate (PO) were evaluated, and the calcium distribution in the presence of STPP and TSPP in CaCl₂ solutions (50 mmol L⁻¹) were investigated. Under conditions simulating industrial toothpaste, the concentration of fluoride in calcium carbonate suspensions (30 g/50 g) was measured by ion chromatography to investigate the effects of chelating agents on calcium ions. Among all the chelating agents, STPP and TSPP have the highest retention rate of fluoride, indicating better calcium binding capacity. Preliminary studies were carried out in CaCl₂ solutions to investigate the influence of concentration and pH on the chelating performance of STPP and TSPP. The distribution of free calcium, chelated calcium, and precipitated calcium in CaCl₂ solution in the presence of STPP and TSPP were investigated to reveal two different calcium-chelation mechanisms and laws for STPP and TSPP. This work has a positive guiding significance for the stabilisation of calcium and fluoride in toothpaste formula.

在这项研究中，评估了三聚磷酸钠（STPP），焦磷酸四钠（TSPP），柠檬酸三钠（TSC）和草酸钾（PO）的钙离子结合能力，并在存在STPP和TSPP的情况下对钙离子的分布进行了评估。研究了CaCl ₂溶液（50 mmol L ^-1）。在模拟工业牙膏的条件下，通过离子色谱法测量碳酸钙悬浮液（30 g / 50 g）中氟化物的浓度，以研究螯合剂对钙离子的影响。在所有螯合剂中，STPP和TSPP的氟化物保留率最高，表明其更好的钙结合能力。在CaCl ₂中进行了初步研究解决方案，以研究浓度和pH对STPP和TSPP螯合性能的影响。研究了在存在STPP和TSPP的情况下CaCl ₂溶液中游离钙，螯合钙和沉淀钙的分布，揭示了STPP和TSPP的两种不同的钙螯合机理和规律。这项工作对于稳定牙膏配方中的钙和氟化物具有积极的指导意义。