No abstract

A new reagent, 2,4,6-tripyridyl-strlazine (TPTZ), is proposed for the colorimetric determination of iron. The intense violet color formed by TPTZ with iron(ll) is due to the ion Fe(TPTZ)2+2,

An organic analytical reagent, 4 : 7-diphenyl-1 : 10-phenanthroline (bathophenanthroline), which is specific for iron, is described for the ultra-micro spectrophotometric determination of iron. The reagent has been applied to the determination of amounts of iron ranging from 1 to 10 pg in 100 ml of water. It forms a iris type molecular complex ferrous ion whose wavelength of maximum absorption is 533 m p arid molecular extinction coefficient is 22,400. An extraction procedure for the isolation of the coloured complex from its aqueous solution increases the sensitivity and extends the specificity to the point where no known interference b:y either metal cations or common anions such as chloride, nitrate, acetate, sulphate or chlorate occurs. The method has been applied to the determination of raw and purified well water provided by municipal water supply systems. Copper does not interfere.

A new indicator, designated calcein, has been prepared for the titration of calcium in the presence of magnesium with disodium dihvdrogen ethylenediamine tetraacetate.

No abstract