Boxcar injections for chiral separations

As described in Chapter 1, the optimum process for separation of a binary mixture is more than often SMB chromatography due to the continuous nature and the efficient use of both mobile phase and stationary phase. However, the effort required to both optimize and stabilize a SMB based separation is complex and time consuming. Consequently, for one off separations it may not be prudent to use a technique that is 

The technique of boxcar injections (not to be confused with boxcar chromatography) can be extremely productive for iso-cratic elution in any mode of chromatography and should always be considered when scaling up a separation. The preparative HPLC of an enantiomeric mixture utilising a chiral stationary phase is described here to demonstrate the approach for separation of a binary mixture. 

At a loading of 20 g on the 10 cm diameter column a third peak was observed which, upon further investigation, proved to be 

It is important to note that the technique of boxcar injections is by no means restricted to chiral separations and should always be considered for any separation performed under isocratic elution. 

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