The invention extends the utility of apparatus used to extract medicinal cannabis compounds into an eluate by separating a portion of medicinal cannabis compounds contained within a portion of eluate at a first extraction target level providing enough clean solvent to continue extraction operations. A high efficiency concentrator such as a rotary evaporator or a wiped film evaporator processes eluate from one or more tanks or extraction vessels creating clean solvent when extraction targets are met or when clean solvent is exhausted. This manages eluate concentration levels and limits the quantity of concentrated medicinal cannabis compounds on site at any moment in time. The invention enables a business model for keeping medicinal cannabis compounds within a legal system, and reduces pollution because law enforcement would no longer have to burn large quantities of cannabis plant matter.