@article{oai:kitami-it.repo.nii.ac.jp:00006205,
 author = {佐々木, 満雄 and 岡, 宏 and 井上, 貞信},
 issue = {2},
 journal = {北見工業大学研究報告},
 month = {Mar},
 note = {application/pdf, The colour of the humic acid in sodium hydroxide aqueous solution is destroyed in the presence of oxygen and ultraviolet rays. It was shown that the humic acid extracted through the medium of NaOH, CH_3COONa and Na_4P_2O_7 in aqueous solution, differs in the rate of colour-fading respectively, and that the different rates of colour-fading were caused by the defference in the quantities and the components of the ash contained in the peat humic acid. The effect of restraining the colour-fading was examined by adding various metal ions components of the ash in the peat humic acid in sodium hydroxide aqueous solution, when it is irradiated with ultraviolet rays. The result showed that the effect produced by restraining the colour-fading arises regularly in the order of Al^<3+>, Fe^<3+> and Ca^<2+>.},
 pages = {213--220},
 title = {泥炭フミン酸アルカリ水溶液の紫外線による退色におよぼすフミン酸中の金属の影響},
 volume = {2},
 year = {1968}
}