| 摘要 |
PCT No. PCT/AT91/00128 Sec. 371 Date Jul. 31, 1992 Sec. 102(e) Date Jul. 31, 1992 PCT Filed Dec. 12, 1991 PCT Pub. No. WO92/10739 PCT Pub. Date Jun. 25, 1992.An indicator for use in a luminescence-optical configuration for continuous and reversible measurement of the pH of a sample within a relevant measuring range (M), whose luminescence decay time tau is dependent on the pH of the sample, is characterized by the following properties. The pKa value of the acidic or basic indicator is in the relevant measuring range when the indicator is in its electronic ground state (S0). The protonation rate kp of the base, or deprotonation rate kdp of the acid in the excited state (S1, X) of the indicator is lower than the decay rate kA of the excited state, and the luminescence decay times tau S and tau B of the acidic forms (AH*, BH+*) and the basic forms (A-*, B*) of the indicator are different from each other. If the pKa tau value of the indicator in its electronically excited state (S1, X) is within the relevant measuring range, the protonation rate kp of the base, or deprotonation rate kdp of the acid in the excited state (S1, X) of the indicator is higher than the decay rate kA of the excited state.
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