The Extraction Spectrophotometric Determination of Iron(III) with Eriochrome Cyanine R and Tridodecylethylammonium Bromide

Abstract

Abstract A sensitive spectrophotometric procedure for the determination of iron(III) has been developed, utilising the ternary complex system of iron–Eriochrome Cyanin R–Tridodecylethylammonium. The iron–Eriochrome Cyanin R chelate anion was extracted with tridodecylethylammonium bromide in xylene. The extracted species had an absorption maximum at 613 nm in the organic layer. The optimum pH range for the extraction was 5.8–6.5. Beer’s law held for 0.2–2 μg of iron(III) in 5 ml of the organic layer. The molar absorptivity of the extracted species was 1.73×105 cm−1·l mol−1·1 at 613 nm. The composition of the ternary complex was assumed to be (Remark: Graphics omitted.) Lead, mercury, tin, chromium, beryllium, thorium, uranium, nitrate, iodide, thiocyanate, and perchlorate interfered with the determination of iron(III).