Quench-Flow Technique
Rapid quench-flow is a well established kinetic technique where the experimentalist can isolate intermediates and products within a reaction mechanism and analyze them by analytical methods providing a means of specifically identifying these components. This is a complementary technique to stopped-flow and can be used when the reaction does not contain spectroscopic changes or changes cannot identify specific reaction components. 
Small volumes of solutions are driven through a high efficiency mixer and flow into a delay (or ageing) loop. After a set time, the reaction is stopped (or quenched) by the addition of a chemical quench solution. This finite time is controlled by the speed and duration of a single push, or by two pushes with a variable delay between them. By collecting a series of quenched samples, quenched at different times the kinetics of the reaction can be determined using the appropriate technique.
The rapid quench-flow systems from TgK Scientific are capable of delivering quenched samples with ages from a few milliseconds to a 100 seconds.
Note that we can also offer a quench-flow option, the qPod for the double mixing stopped-flow, SF-61DX2 model providing a quenching device operating from approx 30 ms to 250 s.
Relevant Application Notes
AN.005.R63
Rapid quench flow studies of enzymatic cleavage of covalently closed circular DNA using the RQF-63 Rapid Quench Flow System
