%0 Journal Article
%T Spectrophotometric Determination of Aminophenol Isomers in Aqueous Solution using 1,2-Naphthoquinone-4-sulphonate Reagent
%A T. N. Al-Sabha
%A N. N. Habeb
%J Pakistan Journal of Analytical and Environmental Chemistry
%D 2011
%I University of Sindh
%X A spectrophotometric method was developed for the quantitative determination of aminophenol isomers. The method is based on their reaction with 1,2-Naphthoquinone-4-sulphonate (NQS) reagent in aqueous basic medium forming colored products with maximum absorption at wavelengths 488, 480 and 535 nm for o-, m- and p-aminophenol respectively. Beer¡¯s law is obeyed over the concentration range of 0.2-10, 0.08-7.2 and 0.08-18 ¦Ìg ml-1 with molar absorptivity values of 5166.6 ,6613.6 and 7673.6 L mol-1 cm-1 for the above isomers, respectively. The average recovery was ranged between 99.14 % to 102.5 % and the precision was better than 4.0 %. The limit of detection was in between 0.0348 and 0.05188 ¦Ìg ml-1. The products are formed in ratio of 1:1 and the stability constants are 3.97¡Á107, 8.58¡Á105, 2.95¡Á105 L mol-1 for the above isomers, respectively. The method was applied successfully for the determination of o-aminophenol in river, tap, spring and sea waters.
%K NQS
%K Aminophenol isomers
%K Spectrophotometry
%K Aqueous solution.
%U http://ceacsu.edu.pk/PDF%20file/Volume%2012%20No%201%20and%202/68-75.pdf