@article{oai:repo.qst.go.jp:00045178, author = {C, Bai Y and Wu, Fengchang and Liu, Chongqiang and Y, Guo J and Fu, Pingqing and S, Xing B and Zheng, Jian and et.al and 鄭 建}, issue = {1}, journal = {Analytica Chimica Acta}, month = {May}, note = {We describe an ultraviolet absorbance titration method that can be used to determine complexing capacities and conditional stability constants of humic substances with metal ions such as Cu(II) and Hg(II). Two fulvic acids and one humic acid were used for this study. UV absorbance of HSs gradually increased with the addition of Cu(II) or Hg(II) after blank correction, and these increases followed the theoretical 1:1 (ligand:metal ion) binding model. The results from the absorbance titration calculation for HSs with Cu(II) and Hg(II) compared well with those from fluorescence quenching titration. The titration of the model compound L-tyrosine with Cu(II) proved the validity of this method, and the K and CL were within 2.3 % and 7.4 % of the fluoresence quenching titration. The results suggest that the UV absorbance titration can be used to study the binding capacities of HSs and/or dissolved organic matter with trace metals. The advantages and disadvantages of the absorbance titration method were also discussed.}, pages = {115--121}, title = {Ultraviolet absorbance titration for determing stability constants of humic substances with Cu(II) and Hg(II)}, volume = {616}, year = {2008} }