Spectrophotometric determination of a number of aliphatic amines in aqueous solution and application to some pharmaceutical preparations

ABSTRACT A simple , rapid and sensitive spectrophotometric method for the determination of aliphatic amines was developed .The method is based on the proton transfer reaction using 3,5- dinitrosalicylic acid (DNS) reagent in basic medium forming colored products with maximum absorption at 415 nm .The molar absorptivity ranged from 5100 l. mol-1.cm-1 for tributylamine to 12000 l. mol-1.cm-1for dibutylamine .The method is obeyed Beers law over the concentration range (0.12-12) g.ml-1.The accuracy ( average recovery ) is 99.73% and the precision (RSD) is less than 4.50% .This method is applied successfully for the assay of ethanolamine and ethylenediamine in their pharmaceutical preparations .