College of Chemistry Chemical Engineering, and Environmental Engineering, Liaoning University of Petroleum & Chemical Technology, Fushun, Fushun 113001, China.
Analyst. 2018 Nov 5;143(22):5568-5577. doi: 10.1039/c8an00612a.
A reliable method for the determination of dissolved Cu2+ and Pb2+ species in water via a diffusive gradient in thin films (DGT) device using water-soluble carbon nanodots (CD) as the binding agent was developed (CD-DGT). The uptake of dissolved Cu2+ and Pb2+ species by CD-DGT increased linearly with a deployment time of over 120 h, while the uptake of Ca2+, Mg2+, Cd2+, Zn2+, Ni2+, and Co2+ by CD-DGT has no significant linear accumulation during the same deployment time. The concentrations of the dissolved Cu2+ and Pb2+ species measured using CD-DGT are in good agreement with the element concentrations spiked directly in a tested synthesis solution. The performance of CD-DGT for the determination of dissolved Cu2+ and Pb2+ species is found to be independent of ionic strength in the range of 0.001-0.05 mol L-1 and in the pH range from 5 to 8. The presence of fulvic acid and tannic acid has no significant influence on the uptake of dissolved Cu2+ and Pb2+ species by CD-DGT under the tested conditions. In different water samples, good agreement was observed between the dissolved Cu2+ and Pb2+ concentrations measured by CD-DGT, and diffusive equilibration in the thin film devices was found. Based on the results obtained, CD-DGT enables the selective and quantitative determination of dissolved Cu2+ and Pb2+ species in water.
一种使用水溶性碳纳米点（CD）作为结合剂，通过薄膜扩散梯度（DGT）装置测定水中溶解态 Cu2+和 Pb2+形态的可靠方法已被开发（CD-DGT）。CD-DGT 对溶解态 Cu2+和 Pb2+形态的摄取量在 120 小时以上的部署时间内呈线性增加，而在相同的部署时间内，CD-DGT 对 Ca2+、Mg2+、Cd2+、Zn2+、Ni2+和 Co2+的摄取量没有明显的线性积累。使用 CD-DGT 测定的溶解态 Cu2+和 Pb2+浓度与直接在测试合成溶液中添加的元素浓度非常吻合。CD-DGT 用于测定溶解态 Cu2+和 Pb2+形态的性能被发现独立于 0.001-0.05 mol L-1 范围内的离子强度和 5-8 pH 范围内的 pH 值。在测试条件下，富里酸和单宁酸的存在对 CD-DGT 对溶解态 Cu2+和 Pb2+形态的摄取没有显著影响。在不同的水样中，CD-DGT 测定的溶解态 Cu2+和 Pb2+浓度与薄膜扩散平衡装置之间存在良好的一致性。基于所获得的结果，CD-DGT 能够选择性和定量地测定水中的溶解态 Cu2+和 Pb2+形态。
