The present invention pertains to an off-line collection system for use with supercritical fluid extraction. The system is comprised of mechanism for collecting analyte associated with the supercritical fluid extraction. The system is additionally comprised of an orifice for controlling flow of analyte to the collecting mechanism. The orifice converts analyte at a high pressure to a lower pressure. The orifice has a high pressure side which receives said high pressure analyte, and a lower pressure side in fluidic communication with the high pressure side which receives said high pressure analyte after it has been converted to a lower pressure. The high pressure side is capable of transporting analyte thereacross without essentially any loss thereof to the low pressure side which is in fluidic communication with the collecting mechanism. The analyte experiences essentially constant pressure as it is transported across the high pressure side. The system is also comprised of mechanism for desorbing the analyte from the collection mechanism. The desorbing mechanism is in fluidic communication with the collecting mechanism. In a preferred embodiment, the system includes mechanism for purging the analyte. The purging mechanism is in fluidic communication with the collecting mechanism. Additionally, the collecting mechanism preferably includes a collection trap in which analyte is gathered, and mechanism for controlling the flow of analyte into the collection trap. The flow controlling mechanism is in fluidic communication with the collection trap and the purging mechanism. The flow control mechanism preferably includes an orifice.