On-column injection system for use of large diameter inside needle capillary adsorption trap devices

Direct coupling of the needle trap to the capillary column in the split/splitless gas chromatographic (GC) inlet with simple modification facilitates full exploitation of the column efficiency, even when using the large volume trap filled with 35 mg of Tenax TA. A schematic diagram of the inlet and of the new modification of the INCAT device and an example of BTEX (benzene, toluene, ethylbenzene and xylenes) analysis is presented. Determination of the repeatability of BTEX analyses resulted in relative standard deviations of 2.4-3.6%.