Quantification of Aniline with Bleaching Powder via Indophenol Reaction and Its Residual Determination in Lubricating Oils

Abstract

A rapid and one step condensation method for trace level determination of aniline is developed in environmental and real sample i.e., lubricating oil. The method involves the use of oxidative coupling reaction for aniline and phenol using bleaching powder as an oxidizing agent in alkaline medium. The dye has a maximum absorption at 640 nm. Beer's law is obeyed in the range of 0.125 to 0.75 μg/ml and its detection limit is 0.025 μg. Molar Absorptivity and Sandell's Sensitivity were found to be 4.4 × 10 $^3$ litres/mol/cm (± 100) and 0.021 μg cm $^{-2}$ , respectively. Standard Deviation and Relative Standard Deviation were found to be ±0.0074 and 3.12% respectively, for 5 μg of aniline in 10 ml of the final volume. All important parameters have been optimized for complete colour reaction and applied for the analysis of aniline in environmental samples i.e. water and air. It is also applied for the residual aniline determination in lubricating oils.