Liquid-Liquid Extraction and Spectrophotometric Determination of Fe(III) using 5-Nitrosalicylaldehyde Semicarbazone (NSS) as an Analytical Reagent

摘要

5-nitrosalicylaldehyde semicarbazone (NSS) is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of Fe (III). NSS reacts with Fe (III) in the pH range 5.2-5.6 to form a coloured complex, which was well extracted into Ethyl acetate. The absorption spectrum of Fe (III) NSS complex in Ethyl acetate shows maximum absorbance at 429 nm. It was observed that the colour development was instantaneous and stable for 48 hrs. The system obeyed Beer's law up to 1-8 μg / cm~3. The molar absorptivity calculated was found to be 1.41 × 10~4 lit mol~(-1) cm~(-1) and the sensitivity of the method as defined by sandal's was 3.3 × 10~(-2) μg/cm~2 . The composition of the extracted species was determined by Job's Continuous variation method and Mole ratio method was found to be 1:1. It may be satisfactorily applied for the determination of Fe (III) with present method.