Study of the Color Reaction of 1-(5′-Naphthol-7′-Sulfonic Acid)-3-4″-(Phenylazo) Phenyl-Triazene with Anionic Surfactants in the Presence of CTMAB

In a medium containing 5 mL of triethanolamine per 25 mL of solution and in the presence of CTMAB 1-(5′-naphthol-7′-sulfonic acid)-3-4″-(phenylazo) phenyl triazene (abbreviated as NSPAPT) reacts with some anionic surfactants,such as sodium dodecyl benzene sulfonate,sodium dedecyl sulfonate,and sodium dodecyl sulfate separately to form a reddish violet colored complex having a mole ratio of (NSPAPT to anionic surfactant) 1 to 2,with its absorption maxima at the wavelength of 598 nm. The results obtained by this method in the analysis of river water and waste water samples gave values of RSD less than 2%,and were in consistency with the results obtained by the methylene blue photometric method.