Abstract: Hydrolysis reaction of bis(halogeno-s-trazine) reactive dyes(including bismonochloro-s-trazine reactive dye Reactive Red KE-3B and bismonofluoro-s-trazine reactive dye Reactive Red LS-2G) were studied by means of reversed-phase ion-pair high performance liquid chromatographic(HPLC). From some aspects such as hydrolysis mechanism of bis(halogeno-s-trazine) reactive dyes, feasibility of HPLC method, qualitative analysis of chromatographic peak and calculation of kinetics parameters, the hydrolysis performance of the bismonochloro-s-trazine reactive dye Reactive Red KE-3B at 90℃，pH11 and the bismonofluoro-s-trazine reactive dye Reactive Red LS-2G at 80℃，pH11 were dicussed, and hydrolysis rate constants of bis(halogeno-s-trazine) form and monohalogenomonohydroxybis-s-trazine form of dyes were determined. The reactivity of bismonofluoro-s-trazine reactive dye Reactive Red LS-2G was found to be 3.4 times that of bismonochloro-s-trazine reactive dye Reactive Red KE-3B. The reaction of the first halogen atom in bis(halogeno-s-trazine) reactive dyes can result in the inactivation of the second halogen atom(i.e. reduction of reaction rate ), so the reactivity of dyes were determined mainly by the first reaction step.

Key words: reactive dye, bis(halogeno-s-trazine) reactive dye, hydrolysis, kinetics, HPLC