ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

[N,N-bis(carboxymethyl)aminomethyl]quinizarin as a new metal chromium indicator for calcium

S. Stankoviansky, V. Podaný, F. Jasinger, and P. Majer

Komensky University, Bratislava

Abstract: By the condensation of iminodiacetic acid with quinizarin in the presence of HCHO [N,N-bis(carboxymethyl)aminomethyl]quinizarin (I) was prepd., which can be used as an indicator for a complexometric detn. of Ca. I has a sharp color change at the equiv. point and indicates as much as 1200 mg. Ca⁺⁺ in 100 ml. of soln. With this new indicator Ca cannot be titrated in the presence of Mg, Ba, Fe, and Cu. The disturbing effect of Mn and Fe can be eliminated by the addn. of TEA and of Cu by the addn. of KCN. Sr is titrated together with Ca. Small amts. of Pb⁺⁺, Hg⁺⁺, Sn⁺⁺, Bi⁺⁺⁺, Sb^+++, Al⁺⁺⁺, Co⁺⁺, Tl⁺ and Ni⁺⁺, and larger amts. of Na and K salts do not disturb the titration. Even at high concns., chlorides, nitrates, acetates, and chromates do not disturb and phosphates disturb the titration. Photometrically from the absorption curves at pH 12 the color change of the indicator was detd.

Full paper in Portable Document Format: 144a265.pdf (in Slovak)

Chemical Papers 14 (4) 265–274 (1960)