Compact instrumentation of a μ-GC for real time analysis of sub-ppb VOC mixtures

We report the instrumentation of a μ-GC system that was capable of performing real-time analysis of sub-ppb-levels of organic mixture vapors. This system consists of a multi-stage preconcentrator/injector, a capillary column with at-column heater configuration and a photo ionization detector (PID). A tablet computer was embedded inside the instrument case to form a stand-alone system that can provide both instrument control and chromatogram data handling without an external computer. Through the compact design of fluidic system, this fully functional GC measured 30 (l) × 17(w) × 8( h) cm and the weight was less than 3. kg. This system could be powered by either a 12. V DC adapter or batteries. Mixtures of 10 organic compounds were tested to demonstrate the performance of this system. Separation of the 10 compounds took only 2. min due to the rapid temperature programming ability of at-column heater. The detection limit ranged from 0.02 to 0.36. ppb can be achieved with 1.0. L sample volume. The analytical cycle including sampling, separation and cooling required only 15. min. The stability of this μ-GC was evaluated by analyzing VOCs at ~. 3. ppb vapor concentration through continuous operation over 24. h. The retention time varied less than 1.2% (RSD, n = 120). The variation in peak areas ranged from 2.2% (benzene) to 5.2% (m-xylene).