High Speed Optical Stopped-Flow Apparatus

A stopped flow apparatus for the study of fast reactions in solution is described. The measured dead time was 270 μsec with an uncertainty in the measurement of 50 μsec. At 410 mμ and an optical density of about 0.09 a change of 0.0044 optical density units could be observed at a flow velocity of 30 m/sec through a 3.0 mm observation tube. Ten milliliters of each of the two reagents are required to fill the system, and less than 1.0 ml of each needs to be expended per experiment.