A system for interfacing a sampling device and a chromatograph and for pre-concentrating analytes in a sample prior to introducing the sample into the chromatographic column is generally disclosed comprising an interface housing with a first channel and an adsorbent housing with a second channel, which contains at least one adsorbent. Valveless conduits permit fluid to be communicated between thesampling device and the first channel, between the first channel and the second channel, and the first channel and the column. In some embodiments, fluid flows in one direction when the analytes are adsorbed and in the opposite direction when analytes are desorbed. In certain embodiments, two different adsorbents are disposed in the second channel to adsorb different types of analytes.