An apparatus and system for passively sampling production fluid from a well is presented. The passive sampling device is used to split two-phase flow and provide a driving pressure differential for a sampling system. Flow through sampling systems require a low pressure differential to be utilized to take a liquid sample, so that the sample retained remains isobaric. When performed in two-phase flow, the pressure differential needs to be relatively high, potentially yielding a non-isobaric sample. By separating out the liquid content of the flow, a low driving pressure is allowed to be used. Thus, this keeps the sample isobaric at a wide range of production flow rates.