Abstract
For the rapid and accurate analysis of nonionics in Cationics-ampholytics-nonionics ternary mixture, the direct determination of nonionics in the mixture without separating the component surfactants has been investigated and the “Direct UV Spectrophotometry” method was developed.
The cationic and nonionic components exhibited the characteristic absorption bands but the ampholytic (imidazoline type) didn't. The λmax was determined as follows : Lauryl benzyl dimethyl ammonium chloride; 257.5, 263, 269.2 mμ, POE nonyl phenol (n=89); 277, 283.5 mμ. Vierordt' method could not be applied to the analysis of mixture, while our experimental results showed that at 277 mμthe observed extinctions of cationics and ampholytics were 0 at the concentration less than 0.03 and 0.025%, respectively, and that the nonionics in mixture could be determined by measuring the extinction of the sample solution, of which the concentration of each component being nonionics ; 0.0020.036%, cationics;<0.03%, and ampholytics;<0.025%.
