Masking agents and metals determined by EDTA
HOME
Email
about
Metals detected by EDTA indicators
Metal ion indicators, masking agents and metals determined by complexation with EDTA.
Metal ion Indicator | Color change | pH range | Metals detected |
Mordant black II Eriochrome black T Solochrome black T | Red to blue | 6 - 7 | Ca, Ba, Mg, Zn, Cd, Mn, Pb, Hg |
Murexide (Ammonium purpurate) | Violet to blue | 12 | Ca, Cu, Co |
Catechol-violet | Violet to red | 8 to 10 | Mn, Mg, Fe, Co, Pb |
Methyl blue | Blue to yellow | 4 to 5 | Pb, Zn, Cd, Hg |
Thymol blue | Blue to grey | 10 to 12 | Pb, Zn, Cd, Hg |
Alizarin | Red to yellow | 4.3 | Pb, Zn, Co, Mg, Cu |
Sodium alizarin sulphonate | Blue to red | 4 | Al, Thorium |
Xylenol orange | Lemon to yellow | 1 to 3 4 to 5 5 to 6 | Bi, Thorium Pb, Zn Cd, Hg |
Masking agents
Masking agent | pH | Ions masked | Ions titrated with EDTA |
Cyanide | 10 | Cu, Co, Ni, Zn, Cd, Hg, Pt, Pd, Ag, Fe | Pb, Mn, Mg, Ca, alkaline earths, rare earths |
Triethanolamine | 10 | Sn, Al, Fe | Zn, Cd, Pb, Mn, rare earths |
Aluminium Fluoride | 10 6 | Al, alkaline earths, rare earths Al, Ti | Zn, Cd, Mn Cu |
Ascorbic acid | 2 | Cu, Fe, Hg | Bi, Th |
Ammonia | 10 | Zn | Cd |
Reference :
Dr. Asif Hussain,Jamia Hamdard, Hamdard Nagar, New Delhi- 110062
"Pharmaceutical Analysis. Theoretical Basis of Analysis: Complexometric Titrations."
|