A novel magnetic N-doped porous carbon material (MNPC) was obtained by mixing urea, sucrose and Fe₃O₄@SiO₂ and calcinating for carbonization. With g-C₃N₄ as intermediate template, the synthesized material has large BET surface area of 219.4 m² g⁻¹ and high nitrogen content of 9.4 wt%. With using MNPC material as sorbent, a new method by coupling magnetic solid phase extraction (MSPE) with inductively coupled plasma mass spectrometry (ICP-MS) was established for enrichment and determination of Cd(II) and Pb(II) in environmental waters. The conditions affecting MSPE were optimized including the effects of pH, sample volume, amount of sorbent usage, adsorption/desorption time and eluent type/concentration/volume. Under the optimized conditions, the developed MSPE-ICPMS method exhibited a good linear dynamic range of more than three orders of magnitude (2–5000 pg mL⁻¹ for Cd(II) and 10–5000 pg mL⁻¹ for Pb(II)) and a low detection limits of 0.49 and 3.1 pg mL⁻¹ for Cd(II) and Pb(II), respectively. The relative standard deviations were in the range of 6.9%–7.3% for the target metal ions. The adsorption/desorption kinetics of the developed MSPE procedure was fast, and the total extraction procedure only cost 7 min (5 min for adsorption and 2 min for desorption) for each sample. The sorbent could be used for at least 5 times. The MSPE-ICPMS method has great potential for the determination of trace and even ultra-trace Cd(II) and Pb(II) in the environment waters.

通过混合尿素、蔗糖和Fe ₃ O ₄ @SiO ₂并煅烧碳化，获得了一种新型磁性N掺杂多孔碳材料(MNPC) 。以gC ₃ N ₄作为中间模板，合成的材料具有219.4 m ²  g ^{-1 的}大BET表面积和 9.4 wt% 的高氮含量。以MNPC材料为吸附剂，建立了磁固相萃取(MSPE)与电感耦合等离子体质谱(ICP-MS)联用富集测定环境水体中Cd(II)和Pb(II)的新方法。对影响 MSPE 的条件进行了优化，包括 pH、样品体积、吸附剂用量、吸附/解吸时间和洗脱液类型/浓度/体积的影响。在优化条件下，将显影的MSPE-ICPMS方法表现出线性幅度超过三个数量级（PG 2-5000毫升动态范围内具有良好^-1镉（II）和10-5000皮克毫升^-1对Pb（II） ) 和 0.49 和 3.1 pg mL ^-1的低检测限分别为 Cd(II) 和 Pb(II)。目标金属离子的相对标准偏差在 6.9%–7.3% 的范围内。所开发的 MSPE 程序的吸附/解吸动力学速度很快，每个样品的总提取程序仅花费 7 分钟（吸附 5 分钟，解吸 2 分钟）。吸附剂至少可以使用5次。MSPE-ICPMS 方法在测定环境水体中痕量甚至超痕量 Cd(II) 和 Pb(II) 方面具有巨大潜力。