The synthesis of a new reagent 1-(2-hydroxy-3, 5-dinitrophenyl)-3-(4-phenylazophenyl)-triazene(HDNPAP) and the condition of its color reaction with cethyltrimethylammonium bromide (CTMAB), cetylpyridinium bromide (CPB) and dodecyldimethylbenzylammonium bromide (DDMBAB) have been stuided. In NaOH medium, HDNPAPT reacts with quatermary ammonium cationic surfactant (CTMAB, CPB, DDMBAB) to form a purple-red ion pair complex with the molar ratio of 1:3. The maximum absorption wavelengths of the complexes are at 560 nm for CTMAB and CPB, at 620 nm for DDMBAB. The apparent molar absorptivities of CTM...
