- 作者： 孫炳榕
- 作者服務機構： Contribution from the Department of Chemistry, National Taiwan University
- 中文摘要： Gallein (pyrogallolphthalein) has been first introduced as a metal indicator in the complexometric titration with EDTA (ethylenedi-aminetetraacetic acid) and successfully applied to the titration of zirconium. A method for the direct titration of zirconium with Versene (the disodium salt of EDTA) was proposed. A soluble complex of 1:1 zirconium-Versene was formed during titration. Gallein indicator changed its color from orange red to a clear golden yellow at the end point. Stoichiometric results were brought about within the pH range 0.5~1.6. The sharpest color change was around pH 1.0. The titration was carried out in hydrochloric acid medium. The effect of the presence of various foriegn ions in approximately equimolar proportions on the titration was observed. Forty-eight ions were tested. Among these only the following were found to interfere: antimony(III), cerium(IV), chromate, fluoride, iron(III), molybdenum(III), molybdate, oxalate, permanganate, phosphate, sulfate, tartrate, tin(II,IV), titanium(III) and vanadate.
- 英文摘要： --
- 中文關鍵字： --
- 英文關鍵字： --
