Rapid and Sensitive Spectrophotometry. I. The Accelerated and Stopped-Flow Methods for the Measurement of the Reaction Kinetics and Spectra of Unstable Compounds in the Visible Region of the Spectrum

Abstract

The present form of the accelerated and stopped flow methods for the measurement of the reaction kinetics and spectra of intermediate compounds in biochemical reactions is described. This apparatus gives satisfactory records with only a few tenths of a cubic centimeter of 2×10⁻⁷M iron enzyme solution and covers a time range from a few milliseconds to several minutes. The wavelength range is 370 to 600 mμ, and the spectral interval is 7.5 mμ. The error in optical density measurement is about 1×10⁻⁵ corresponding to a signal‐to‐noise ratio of 5×10⁴ for a response time of 1 sec over the wavelength range of 380–580 mμ. The present performance and range of usefulness considerably exceed that reported previously.