1. A method for sampling formation fluid, the method comprising: introducing formation fluid into a pump, the pump having an inlet and an outlet; segregating the fluid within the pump; pumping the fluid out through a flowline; sensing the fluid with a fluid sensor at or downstream of the outlet of the pump to obtain sensor data; and selectively opening and closing a valve to accept a desired fluid into at least one sample chamber based on the sensor data, wherein the valve is opened and closed during the pumping.