G.F. Hariyanto, N.S. Aminah, A.N. Kristanti, M.I. Abdjan, Y. Takaya
Previous research on brazilein has demonstrated color changes due to pH variations. This study further explores the potential of ethanol extract from sappan wood as a metal detection agent. This study supports Sustainable Development Goals (SDGs), specifically SDG-6 (Clean Water and Sanitation), by advancing environmentally friendly detection techniques and aiding in the monitoring of environmental and public health. Through visual observation and UV analysis, the color changes of the sappan wood extract can be clearly observed. Computational analysis was also conducted to assess the stability and formation energy of the complexes. The extract of sappan wood is yellow; when Pb(NO3)2 and Pb(OAc)2 are added, it changes to pink with absorption maxima at λmax = 462 nm and λmax = 512 nm. The addition of FeCl3 and Fe(NO3)2 results in a beige color with absorption maxima at λmax = 436 nm and λmax = 454 nm. The addition of CuSO4 produces a peach color with absorption maxima at λmax = 444 nm and λmax = 500 nm. The stability of chelate formation, calculated using DFT, indicates that the Fe complex is the most stable, with the highest interaction energy E(2) value of 1907.83 kcal/mol. The Cu complex shows very stable formation with an energy of 824.90 kcal/mol, while the Pb complex exhibits less stable formation with an energy of 296.71 kcal/mol. © 2025, Rasayan Journal of Chemistry, c/o Dr. Pratima Sharma. All rights reserved.
Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga, Jl. Ir. Soekarno No. 119, East Java, Surabaya, 60294, Indonesia; Biotechnology of Tropical Medicinal Plants Research Group, Universitas Airlangga, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Negeri Surabaya, Surabaya, Indonesia; Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Nagoya, Tempaku, 468-8503, Japan
