Abstract: Embodiments of the invention feature methods and apparatus for the efficient utilization of detectors and other components. The apparatus comprises a pump for receiving and propelling one or more samples in a fluid path. The apparatus further comprises a valve element in fluid communication with the pump for receiving the samples from the pump and directing the sample along one fluid path selected from a group. The group comprises a delay path comprising a delay volume, and a chromatography assembly having at least one chromatography column. The apparatus further comprises a detector or grouping of detectors in fluid communication with the delay path and the chromatography assembly for detecting compounds of interest to allow a single detector or single grouping of detectors to receive samples from the two fluid paths.