Multilayered and porous sodium-doped graphitic carbon nitride (GCN-Na) was prepared and employed to the solid-phase extraction of Sr(II). The sorbent exhibits high adsorption capacity and excellent selectivity for Sr(II). This is due to its small interplanar stacking distance caused by doping with Na(I) which matches the size of Sr(II) better than blank GCN. An original solid-phase extraction method based on GCN-Na coupled with ICP-OES was established for Sr(II), the calibration plots are linear ranging from 0.05–10 mg·kg−1 with the correlation coefficients (R2) above 0.999, the limits of detection are in the range of 0.57–1.52 μg·kg−1 and the preconcentration factor of 80 is achieved using 48 mL sample. It was successfully applied in the extraction and detection of trace Sr(II) in tap water, rice and sea fish. Graphical abstract A multilayer porous sodium(I) doped graphitic carbon nitride nanosheet (GCN-Na) was synthesized and exhibited excellent adsorption capability and selectivity for Sr(II). A multilayer porous sodium(I) doped graphitic carbon nitride nanosheet (GCN-Na) was synthesized and exhibited excellent adsorption capability and selectivity for Sr(II).

中文翻译：

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在通过 ICP-OES 测定锶（II）之前，具有适当层间距的钠（I）掺杂石墨碳氮化物作为锶（II）的高选择性吸附剂

制备了多层多孔掺钠石墨氮化碳（GCN-Na）并将其用于Sr（II）的固相萃取。该吸附剂对 Sr(II) 表现出高吸附能力和优异的选择性。这是由于其由掺杂 Na(I) 引起的较小的晶面堆叠距离，其与 Sr(II) 的尺寸匹配比空白 GCN 更好。建立了基于 GCN-Na 结合 ICP-OES 的原始固相萃取方法对 Sr(II)，校准曲线在 0.05–10 mg·kg-1 范围内呈线性，相关系数 (R2) 高于 0.999，检测限在 0.57–1.52 μg·kg-1 范围内，使用 48 mL 样品达到 80 的预浓缩因子。成功应用于自来水、大米和海鱼中痕量Sr(II)的提取和检测。图形摘要合成了一种多层多孔钠（I）掺杂石墨氮化碳纳米片（GCN-Na），并表现出对 Sr（II）的优异吸附能力和选择性。合成了多层多孔钠（I）掺杂的石墨氮化碳纳米片（GCN-Na），并表现出优异的吸附能力和对 Sr（II）的选择性。