A New Extractive Spectrophotometric Method for the Determination of p-Nitroaniline

Department of Chemistry, Ravishankar University, Raipur-192 010

Manuscript received 18 March 1982, accepted 28 September 1982

On the basis of diazotization reaction a new sensitive extractive spectrophoto­metric method has been developed for the determination of \(p\)-nitroaniline. \(p\)-Nitro­aniline is diazotized with nitrite in hydrochloric acid medium and subsequently coupled with α-naphthol to give a purple coloured azo dye in alkaline medium. (λ_max 580 nm, ԑ_max 3.7 x 10⁴ 1. mole^-1 cm^-1. The azo dye formed is extractable in iso-amyl alcohol. giving a blue coloured extract having molar absorptivity and Sandell's sensiti­vity of 5.2 x 10⁴ 1. mole^-1 cm^-1, 0.0026 µg cm^-2, respectively at λ_max 610 nm. Several common species, viz, inorganic cations, phenols, nitrocompounds, aldehydes, ketones, etc. present in polluted water do not interfere. Primary aromatic amines interfere when present in high concentration.