Abstract: Systems and methods are described for transporting sample using a first vacuum configuration and subsequently isolating the sample at a valve prior to introduction to an analysis system, where a second vacuum configuration transports other fluids through the system. A system embodiment can include, but is not limited to, a valve system including a first valve in fluid communication with a sample reservoir and a second valve having at least a first vacuum configuration to fluidically couple a first vacuum line with the first valve and having a second vacuum configuration to fluidically couple a second vacuum line with the first valve; a sensor system configured to detect presence or absence of a fluid at the first valve; and a controller configured to control operation of the second valve to block access of the first vacuum line to the first valve upon detection of the fluid at the first valve.