Pyridinium, 1,1'-[(6,13-dichloro-4,11-disulfo-3,10-triphenodioxazinediyl)bis[imino-2,1-ethanediylimino[6-[(2,5-disulfophenyl)amino]-1,3,5-triazine-4,2-diyl]]]bis[3-carboxy-, dihydroxide, bis(inner salt), hexasodium salt

Hydrolysis

Description of key information

The rate constant (k_obs) of Everzol SB26 at 25°C are 3.5× 10^-4, 2.77× 10^-4 and 1.42× 10^-3 hour^-1 respectively at pH=4, pH=7 and pH=9. And the half-life time of Everzol SB26 at 25°C are 82.5 days, 104 days and 20.3 days respectively at pH=4, pH=7 and pH=9 (OECD TG111).

Additional information

In Main study,the mean recoveries of the buffer solutions at pH=4 and t=0 fell within the criterion range of 80 -120% . It demonstrated that the analytical method was adequate to support the hydrolysis study on the test substance. At pH=7, the mean recoveries of the buffer solutions at t=0 fell within the criterion range of 80-110%. At pH=9, the mean recovery of the buffer solutions at t=0 fell within the criterion range of 4.7 -110%. For testing of pseudo-first order kinetics the mean logarithms of the relative concentrations between 10% and 90% were plotted against time. At all temperatures linear relationships were obtained. The half-life times of the test substance were determined according to the model for pseudo-first order reactions. All logarithms of the relative concentrations were correlated with time using linear regression analysis. The rate constant (k_obs) and half-life time of the test substance at each temperature was obtained and the Arrhenius equation was used to determine the rate constant and half-life time at 25°C.Therefore, the rate constant (k_obs) of Everzol SB26 at 25°C are

3.5× 10^-4, 2.77× 10^-4 and 1.42× 10^-3 hour^-1 respectivelyat pH=4, pH=7 and pH=9. And the half-life time of Everzol SB26 at 25°C are 82.5 days, 104 days and 20.3 days respectively at pH=4, pH=7 and pH=9.