With this simple solution in place, we have initiated efforts to implement routine reaction monitoring using one of our walk-up systems. One of the biggest drawbacks to achieving this goal in the past has been the inability to handle heterogeneous reactions. Although solutions to this have been developed utilizing ingenious sampling systems , the back-flush represents a simple method to mitigate this issue. Although, one can argue that utilizing this approach for monitoring heterogeneous reactions will not allow truly representative sampling of a reaction mixture, we have assembled a portfolio of examples, which we believe will provide value in a medicinal chemistry setting, and these examples will be reported in due course