Rapid scanning stopped-flow commercial availability

Measurements of absorption as a function of time can provide a wide range of useful information. Brzovic and Dunn [8] describe instrumentation for measuring the time dependence of absorption spectra after rapid mixing of reactants. Several rapid-scanning stopped-flow instruments are commercially available reactions that take place in a millisecond or longer can be studied. Enzyme-catalyzed reactions with natural chromophores, such as NADH, are discussed, and the substitution of a colored metal center [Co(II)] for a colorless one [Zn(II)] are also described. Detailed mechanistic conclusions for horse liver alcohol dehydrogenase (LADH) are given. 

A number of stopped-flow systems are commercially available. Three of the most used are manufactured by Atago Bussan (formerly Union Giken), Japan Dionex (formerly Durrum), USA and Hi-Tech Scientific, UK. These also manufacture rapid scan spectrophotometers, multimixer, temperature-jump and flash photolysis equipment. 

Options for multichannel LC-CD detection do exist.f " Stopped-flow accessories for commercial instruments are available that allow part of an eluted fraction to be taken off-line into a microcell placed in the regular sample compartment where data are measured in the normal way. The method still requires rapid scanning capabilities. Repeated injections and multiple scans can be averaged to improve the quality of the signal. A major deterrent to the progress in the early development of HPLC-CD detection was the lack of a dedicated instrument at a reasonable cost, the only option being a fully equipped CD instrument. 

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