Determination of photophysical parameters of tryptophan molecules by methods of laser fluorimetry

The photophysical parameters of tryptophan molecules at a low concentration in aqueous solution are measured by the methods of nanosecond laser fluorimetry upon excitation by 266-nm laser pulses. Two-step processes (reversible and irreversible photochemical transformations) taking place in this case are described quantitatively and it is shown that they can be neglected at the exciting photon flux density F < 5×10²⁴ cm^-2 s^-1 in ~10-ns pulses.