@article{oai:toyama.repo.nii.ac.jp:00003781,
 author = {大井, 信一},
 issue = {1/2},
 journal = {富山大学工学部紀要},
 month = {Mar},
 note = {The alcoholic solution of 2,2'-bibenzoxazoline forms a red colored water-soluble chelate compound with micro amounts of calcium in a highly basic solution. The reaction is very sensitive and selective in the presence of KCN. Therefore, the fundamental conditions for the determination of calcium with this reagent have been investigated. The calcium chelate has a maximïím absorbance at 510--512 mμ. against the reagent blank solution. The optimal alkalinities of solution for developing of the color are 0.028--0.052 N.NaOH.Reproducible result can be obtained when the absorbance is measured between 10--15 min. after the reagent added. The calibration curve follows Beer's law up to 1.2 μg./ml. of calcium. The interferences of heavy metals such as Fe, Co, Ni, Cd and Mn are eliminated in the presence of KCN. The chelate compounds of Sr and Ba are decomposed with small amounts of Na_2CO_3 while the calcium chelate is stable., 00/02/02 02:02, Article, 02/01/12},
 pages = {55--60},
 title = {09/02/02},
 volume = {12},
 year = {1961}
}