Reduction of mercury(Ⅱ) by electrons contained in carbon dots:An environmentally friendly cold vapor generation for mercury analysis

作者：Tao Chen; Yao Lin; Haochen Li; Rui Yang; Xiandeng Hou; Baozhan Zheng^*; Chengbin Zheng^*

来源：Chinese Chemical Letters, 2020, 31(10): 2678-2682.

In this work,the reduction of mercury ions(Hg2+) to elemental mercury(Hg0) was easily achieved using highly reductive carbon dots(r-CDs),which synthesized from sucrose by a simple and cost-effective method.After a careful mechanistic study,the reduction was probably accomplished with the large numbers of electrons contained in r-CDs rather than the oxidation of its functional groups.Additionally,a3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay showed that the r-CDs were nontoxic to wildlife and human beings.Consequently,the r-CDs were used as an alternative to toxic reductants(SnCl2 or NaBH4) for the sensitive and in situ determination of mercury by cold vapor gene ration(CVG) coupled to a miniature point discharge optical emission spectrometer(μPD-OES).Limit of detection of 0.05 μg/L was obtained for Hg2+,with relative standard deviation(RSD) less than 5.4% at a concentration of 5 μg/L.The accuracy of r-CDs induced CVG-μPD-OES was validated by the determination of mercury in a certified reference material(DOLT-5,dogfish liver) and five natural water samples collected from different rivers and lakes in Chengdu City,Since r-CDs are nontoxic and prepared from abundant and inexpensive sucrose,the r-CDs induced CVG-μPD-OES retains the great potential for the inexpensive and enviro nmentally friendly field analysis of mercury in natural water.The accuracy of the proposed method was validated by the analysis of a certified reference material and several water samples with satisfactory results.

• 单位
  四川大学