RK-Spectro Technical Note 34: Design of stopped flow sequence, determination of minimum washing volumeLatest updated: February 16, 2021
A Technical Note that describes the process for the determination of minimum washing volume for stopped-flow sequence designs. In a stopped-flow experiment, it is necessary to completely wash the flow path from the last mixer to the observation point of the cuvette, or in other words to get rid of the solution from the previous shot. If the volume pushed into the cuvette is too small, a stationary state inside the cuvette may not be reached and part of the kinetics lost. The volume needs for proper washing of the cuvette are estimated to 4 or 5 times the dead volume of the cuvette, but this volume is dependent on the nature of the reactants. The aim of this technical note is to show the importance of the volume used during the push. The reduction of Dichloroindophenol (DCIP) by ascorbic acid at pH=9 is used for the determination of this minimal volume.