University Chemistry ›› 2026, Vol. 41 ›› Issue (8): 389-401.doi: 10.12461/PKU.DXHX202507135

• Chemistry Laboratory • Previous Articles     Next Articles

Coordination titration for copper ion determination using a novel fluorescent turn-on indicator: design and implementation of an analytical chemistry experiment

Xiuhong Liu, Cunxu Yan, Yue Zhang, Xuesong Gao, Haifeng He   

  1. School of Chemistry and Chemical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330038, Jiangxi Province, China
  • Received:2025-07-28 Accepted:2025-10-17 Published:2026-08-25
  • Contact: Xiuhong Liu, Haifeng He E-mail:xiuhong0627@163.com;hehf0427@jxstnu.com.cn

Abstract: Guided by the student-centered teaching philosophy, it combines theoretical knowledge with practical application, experimental design with verification procedures, enabling students to employ a novel fluorescent compound as an indicator in coordination titration for copper content determination. The experiment enhances students' comprehension of coordination titration principles while fostering their investigative skills and innovative thinking. Distinct from conventional colorimetric indicators, the fluorescent indicator used in this study demonstrates a unique “off-on” fluorescence transition at the endpoint, the high sensitivity response of this new fluorescent indicator to Cu2+ can achieve quantitative analysis of Cu2+ concentration as low as 1 × 10-5 mol·L-1, and eliminating the need for expensive fluorescence spectrophotometers. The titration procedure is straightforward, environmentally benign, and safe, with high analytical accuracy. Students demonstrated strong engagement and achieved considerable satisfaction through this experimental learning experience.

Key words: Fluorescent indicator, Coordination titration, Copper ion, Low concentration, Experiment teaching