The Determination of Inorganic Sulphate in Sodium Lauryl Sulphate
The official method for the determination of inorganic sulphate in sodium lauryl sulphate is time‐consuming. Separation of organic and inorganic sulphate via the lead salts followed by complexometry leads to a rapid and convenient method with readily reproducible results.
Complexometric Determination of Sulfate
A simple and rapid method for the determination of sulfate in materials obtained during extraction of uranium from ores is based on precipitation as lead sulfate from acid solution containing isopropyl alcohol. The precipitate is filtered and redissolved in an excess of measured standard (ethylenedinitrilo)tetraacetic acid (EDTA) solution. The excess of the latter is then backtitrated with a standard zinc chioride solution and Eriochrome Black T as indicator. A detailed study of the optimum conditions for the precipitation of lead suifate has been carried out, and the degrees of interference of phosphate, arsenate, iron, and uranium ions have been tested. The method is virtually free of interferences and gives accurate results in the range 0.1 to 100% sulfates the time required for a determination is about 30 to 45 minutes. (auth)
Metallindikatoren VII. Ein auf Erdalkaliionen ansprechendes Phtalein und seine analytische Verwendung
A derivative of phenolphtalein, carrying two iminodiacetic acid groups, which enable the substance to bind metal cations, is described. Complex formation with Mg+2, Ca+2, Sr+2, Ba+2 and Zn+2 has been investigated quantitatively and the absorption spectra of the different complexes are given. The new substance, called Phtalein-Complexone, is an excellent indicator for the complexometric titration of alcaline earth metals. A method for the titration of sulfate is also given.