5:6-Benzoquinaldinic acid as an analytical reagent: Determination of titanium

The reagent 5 :6 -benzoquinaldisic acid precipitates titanium(lV) completely from solution at and above pH 3.0 in the presence of rare earths. Coprecipitation of magnesium and the alkaline earths is easily prevented by the addition of ammonium chloride. Separation from iron(III), thorium or zirconium can be carried out in the presence of complexone III. magnesium sulphate being used as a demasking agent. Separation from aluminium is not possible. The titanium precipitate is not of definite composition and so it is ignited to the oxide before weighing.