SIMULTANEOUS DETERMINATION OF TRACE AMOUNTS OF IRON(III) AND TITANIUM(IV) BY FLOW-INJECTION WITH SPECTROPHOTOMETRIC DETECTION

The simultaneous determination of iron(III) and titanium(IV) has been carried out by flow injection using Tiron as the colour-developing reagent. The sample is injected simultaneously at two inlet points separated by a silver reductor column and the two plugs are allowed to meet the Tiron solution. The coloured slugs reach the detector cell at different times, giving double peaks, and are monitored at 430 nm. The first peak affords the concentration of iron(III) plus titanium(IV) and the second the concentration of titanium(IV). The system allows 30 samples to be analysed per hour for iron(III) and titanium(IV). Results are presented for the quantitative analysis of 11 standard reference rock samples of the Geological Survey of Japan. The average precision (relative standard deviation) is 1.0 and 0.87% for total iron and titanium(IV) in rocks, respectively.