Spectrophotometric Determination of Iron with 2-Thioxo-5-nitroso-1, 3- dimethylperhydropyrimidine-4, 6-dionet

Abstract

2-Thioxo-5-nitroso-1, 3-dimethylperhydropyrimidine-4, 6-dione (TNDP) was synthesized and fundamental conditions for the determination of iron with the TNDP was investigated. TNDP reacts easily with iron (III) to form a water-soluble blue complex. Iron (II )-TNDP complex has an absorption maximum at 630 nm against a reagent blank and shows a definite absorbance over the pH range from 5.5 to 6.8. The calibration curve obeys the Beer's law over the range from 0 to 3 pglml of iron (II) at 630 nm; the molar extinction coefficient of the complex and the sensitivity for log(10/1) = 0.001 level are 2.23x 10 cm'mol'. l and 2.49x 10-9 μgcm^-2, respectively. The variation coefficient was 0.68% in the case of 1 pg/m/ of iron (II ). The ratio of iron (II ) to TNDP in this complex was confirmed to be 1: 3 by the continuous variation method. Large amount of cobalt (II) and copper 00 interfered with the determination.