  We have developed a luminescence-measurement system for liquid
bio/chemiluminescence that can obtain quantitative luminescence spectra as the
absolute total number of luminescence photons at each wavelength or photon
energy and quantum yields. Calibration of light-collection efficiency in the
system is performed with a reference double-plate cell. This method is
applicable to sample cells of any kind suitable for measurement, which is a
great advantage over previous techniques in practical experiments. Using this
system, the quantum yield of aqueous luminol chemiluminescence was obtained as
1.23-+0.20%, which is in good agreement with previously reported values.
