Abstract
Iron in samples containing several elements which showed the color of pertitanic acid by adding a mixture of fluotitanic acid and hydrogen peroxide (the coloring reagent) was determined by transmittanceratio method. The iron in a sample solution of about 5 N hydrochloric acid was extracted with ether and a known quantity of iron (III) and the coloring reagent were added to the residual solution. Against this colored solution was measured the transmittance of the original sample solution colored by the coloring reagent, by transmittance-ratio method. Basic experiments using artificially prepared solutions were worked out. Several samples of silicate minerals containing 208% iron were then analyzed and results with differences of less than about +1.5% comparing with thcse by the gravimctric method were obtained. The time required for one determination was less than one-fourth of that for the gravimetric method.
