366 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS QDI Determination by Ammonia Evolution The hydrolysis of pure QDI or QDI mixtures to give ammonia was done using a modified Folin-Farmer micro-Kjeldahl apparatus. QDI was weighed into the reaction vessel, which contained lg Na2COa/100 ml (pH 9.6) and other reactants as desired. Water or 6% H20•. was added after the system was connected. Reactions were allowed to proceed for one hour (Table II). Table 'n' QUINONEDIIMINE, AMMONIA EVOLUTION % of Theoretical Reactants* Average ñ St, Dev. No, of Expts. QDI (No H202) 17.1 _.+ 6.0 4 QDI (H20•) 18.4 _+ 6.0 5 QDI: PPD 1:1 5.8 --+ 1.8 7 QDI: Resorcinol 1:2 (2 hours) 2.0 +-- 0.9 3 *QDI varied from 0.06-0.3 g. in 50 mi. 1% Na2CO3, pH 9.6 H20• when used, at 3% time I hr. QDI in Oxidation Mixtures/ Ammonia Evolution Various oxidation dye intermediates (PPD, resorcinol, m-amino- phenol), as well as BB, both with and without peroxide, were subjected to hydrolytic conditions as described above and any evolution of am- monia was noted. PPD was used in a 1% solution, and the other com- ponents were used in the proportions indicated in Table III. QDI Determination by Spectral Method A standard absorption spectrum for QDI was established by dissolv- ing a known amount in absolute ether absorption maxima, 255 mu and 265 mu molar extinction coefficient (at 265 mu), 24,000 (Fig. 4). The stability of QDI in aqueous mixtures was determined as follows:

REACTIONS OF OXIDATION DYE INTERMEDIATES 867 Standard Curves ß ß ß ß ß ß •. * I I I I 21o 250 X (m•) ß ß *** ***, ß ß ß : ß ß ß : : ß ß ß ß ß ß t• ** ß ß I I i i 300 Figure 4. Quinonediimine and resoreinol in ether. QDI, , (265 mu), 24,000. ... Resorcinol, , (275 mu), 19,600