Liquid-Liquid Extraction and Spectrophotometric Determination of Fe(III) using 5-Nitrosalicylaldehyde Thiosemicarbazone (NSTS) as an Analytical Reagent.

5-Nitrosalicylaldehyde thiosemicarbazone (NSTS) is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of Fe (III). NSTS reacts with Fe (III) in the pH range 4.0 -6.0 to form a coloured complex. This was well extracted into Iso Amyl Alcohol. The absorption spectrum of Fe (III) NSTS complex in Iso Amyl Alcohol shows maximum absorbance at 435 nm. It was observed that the color development was instantaneous and stable. The system obeyed Beer's law up to 1–7 μg/cm³. The molar absorptivity calculated was found to be 2.88 x 10⁴lit mol⁻¹cm⁻¹ and the sensitivity of the method as defined by sandal's was 0.0166 μg/cm². The composition of the extracted species was determined by Job's Continuous variation method and Mole ratio method was found to be 1:4. It may be satisfactorily applied for the determination of Fe (III) with present method.