Abstract
A rapid scanning spectrophotometer was used for the measurement of the O2 replacement reaction by CO from O2Hb solution at a low Pco range. The Hb concentration in the reaction mixture was equivalent to 3, 500-fold-diluted whole human blood. The reaction rate was measured at a Pco of 3.3 and 6.5mmHg and a Po2 of 100, 200, 343, 499 and 673mmHg, respectively. The most prominent spectrum change was observed at the Soret-band of 420mμ. The rate of Sco change, dS/dt, was linearly proportional to the Pco. The velocity factor, Fs, was independent of Sco, and was not hyperbolic against the Po, as shown by ROUGHTON, FORSTER and CANDER. But Fs was in an exponential relationship to the Po2 as shown by the following equation within an error of ±10%;
exp (Fs) =-10-3·Po2-1.68.
The authors are grateful to Prof. Masaji MOCHIZUKI for his intimate guidance and and reviewing of the manuscript. They are also greatly indebted to Mr. Takashi ARAI for the construction and improvement of the stopped flow apparatus.
