Combined spectral experiment and theoretical calculation to study the interaction of 1,4-dihydroxyanthraquinone for metal ions in solution

The statement: Hg2+ and Er3+, their reaction abilities for 1,4-DHA were studied by UV-Visible and fluorescence spectroscopies in solution. They all have better response for 1,4-DHA in the spectra with distinct and regular changes. And theoretical calculation concluded that Er3+ easily react with 1,4-DHA over Hg2+ attributed to the low reaction energy of Er3+-1,4-DHA than Hg2+-1,4-DHA.