The object of this invention is to provide a gas sampling system capable of taking discreet samples from a continuous flow of gas or fluid. Said apparatus offers a frame (1) and mounting components in the form of a fixed chuck (4) and a spring-loaded chuck with a sample container (5) mounted there between. The sampling container has self-sealing end cap valve assemblies (76) that automatically open when the sample container (5) communicates with the fixed chuck (4) and the spring loaded chuck (6) and the end cap valve assembly automatically closes when the sample container is removed. A value system allows the gas flow to be directed from one sample container to the other alternatively opening and closing a gas flow path. A sample extraction assembly (14) allows the efficient removal of samples from the sample containers. An extension rod pressurizer (117) in conjunction with the end cap value assembly, such as first end cap valve assembly (76) allow the sample to be pressurized to facilitate easy sample removal.