University Chemistry ›› 2022, Vol. 37 ›› Issue (3): 2106002.doi: 10.3866/PKU.DXHX202106002

• Chemistry Laboratory • Previous Articles     Next Articles

Determination of Chloride Ion by Fajans Method Using Gold Nanoparticles as the Indicator

Yuanfu Zhang(), Jinrong Zhang, Zijing Ren, Xifang Zhang, Dongli Shang, Linjie Wei, Rui Li, Xia Li, Qingwang Xue, Wei Zhang, Shuhao Wang   

  • Received:2021-06-02 Accepted:2021-07-02 Published:2021-07-15
  • Contact: Yuanfu Zhang


In this work, nanomaterial was introduced into titrimetric analysis. Firstly, gold nanoparticles (AuNPs) with negative charges were prepared by reducing chloroauric acid with sodium citrate. Then, based on localized surface plasmon resonance of AuNPs, a novel Fajans method was designed to detect chloride ion using gold nanoparticles as the adsorption indicator to indicate the titration endpoint. The results showed that the method could accurately determine millimole chloride ion. Moreover, the gold and silver in waste liquid can be recycled through complexation reaction, precipitation reaction and redox reaction, which can reduce the cost and pollution. Through the practice of this experiment, students will study the frontier of the nanomaterial, and their interest in scientific research will be stimulated. Furthermore, the scientific research ability will be cultivated. Finally, the application of green chemistry is promoted in teaching.

Key words: Gold nanoparticles, Adsorption indicator, Fajans method, Green chemistry