A downhole fluid property estimating apparatus includes an interface in communication with a fluid in a first pressure zone, a collector in communication with the interface, the collector having a second pressure zone, wherein a second pressure zone pressure is less than a first pressure zone pressure, and a gas chromatograph coupled to the collector. A method includes establishing a first pressure zone having a fluid in communication with an interface, establishing a second pressure zone in a collector in communication with the interface, wherein a second pressure zone pressure is less than a first pressure zone pressure, collecting a fluid sample of the fluid in the first pressure zone using the collector, and estimating the downhole fluid property in-situ using a gas chromatograph coupled to the collector.