EDTA滴定法による鉄,アルミニウム,マンガン,カルシウムおよびマグネシウムの連続定量

DOI Web Site Web Site

書誌事項

タイトル別名
  • Continuous determination of iron, aluminum, manganese, calcium and magnesium mixture by EDTA titration
  • EDTA テキテイホウ ニ ヨル テツ , アルミニウム , マンガン , カルシウム オヨビ マグネシウム ノ レンゾク テイリョウ

この論文をさがす

説明

An acidic solution of hydrochloric acid or perchloric acid cotaining Fe3+, Al3+, Mn2+, Ca2+ and Mg2+ is adjusted to pH 2.0 by addition of ammonium acetate and the Fe is titrated with a standard EDTA solution using salicylic acid as an indicator.<BR>The solution after determination of Fe is treated with EDTA in a slightly excess for Al, adjusted to pH 3.0, heated to boil for the reaction Al and EDTA and the excess of EDTA is titrated with a standard copper sulfate solution using PAN (α-pyridyl-β-azonaphthol) as an indicator.<BR>The above procedure is the same as in the usual method. The solution after determination of Al is adjusted to pH 4.5, heated up to 60°C, EDTA is added in a slight excess for Mn, kept for 10 min and the excess of EDTA is titrated with the standard copper sulfate solution with PAN indicator for determination of Mn without the influence of Ca2+ and Mg2+. Although the formation constant of Mn chelate is found to be greater than that of Cu chelate, Mn2+ showed a red coloration with PAN and the end point of titration can be found without difficulty.<BR>Based on the fact of determination of Mn from a solution of pH 4.5, a continuous determination of Fe, Mn, Ca by titration with EDTA becomes possible. Namely, the solution after determination of Mn is used for determination of Ca and Mg in alkaline medium as usual and the procedure is carried out as follows:<BR>A part of solution after determination of Mn is taken, adjusted to pH 10, EDTA is added in a slight excess for total sum of Ca and Mg, the excess of EDTA is titrated with the standard copper sulfate solution and the sum of Ca and Mg is calculated. The other part of solution is treated with ammonium oxalate solution for precipitation and separation of Ca, and the solution is adjusted to pH 10 and the Mg is determined in the same way as in the detemination of the sum of Ca and Mg.<BR>In case of dealing with a solution of Al-EDTA alone of pH 10, it caused the precipitation of aluminum hydroxide with the liberation of EDTA and the determination became impossible, but it was found that aluminum hydroxide remained unprecipitated in the presence of Fe-EDTA and Mn-EDTA and there was no disturbing influence for titration (Ca+ Mg) and Mg.

収録刊行物

  • 分析化学

    分析化学 9 (3), 238-243, 1960

    公益社団法人 日本分析化学会

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ