Micro-Fabricated Pre-Concentrator Filled with Single-Walled Carbon Nanotubes as Adsorbent Material

As concentration of components in environmental gas is very low, and the available analytical instruments are not sufficiently sensitive, so that micro pre-concentrators developed for effectively concentrating components are very important and necessary. Therefore, in this work a micro pre-concentrator was fabricated for concentrating trace gas. The micro pre-concentrator with 4 parallel channels filled with Single-Walled Carbon Nanotubes (SWCNTs) as adsorbent materials was developed for concentrating volatile organic compounds (VOCs). This choice was done on the basis of the consideration: 4 parallel channels ensure that the pre-concentrator can be filled with a sufficient amount of adsorbent materials. Moreover, SWCNTs was acted as adsorbent material owing to their chemical and thermal stability, a high surface-to-volume ratio, and a large affinity to the non-polar compounds. The experimental results show that the micro pre-concentrator effectively concentrated benzene with a concentration factor of 15 and the chromatography peak broadening was also greatly compressed.