Gas Concentration Method Based On Microfluidic Chip

Industrialization not only promotes economic development, but also brings airpollution. As to the attention of the air quality, people began to air for online real-timemonitoring of various occasions. There is a limit to the sensitivity of the detector, however,for a very low concentration of gas. As a result, the detector is usually not effective on-linemonitoring, which is a unified problem facing the current detector.Gas concentration device can effectively improve the ability of detecting monitoringsystem. It usually placed in the detector front-end and used to improve the concentration ofthe gas to be detected. Microfluidic chip has been widely applied in the analysis anddetection systems. So far, most of the research object is the liquid phase fluid onmicrofluidic chips, however, gas research is very rare. Therefore, the study of gasconcentration of microfluidic chip is of great significance.In this paper, gas adsorption/desorption and gas diffusion membrane two principlesenrichment methods were introduced. On the influence factors of gas concentration andmembrane material, membrane structure are studied, and details the structure of thetwo-chip enrichment methods.According to the research status of existing gas concentrationmethods, this topic proposed a is different from the traditional physical adsorption/desorption gas enrichment method, Which uses liquid absorbing gas, so that a lowconcentration of gas is concentrated in a fixed volume of liquid solution.For this method, different gas need to use different absorption solution. In view of theammonia gas, this paper designed a kind of small volume, simple structure, low cost, gasenrichment, separation and detection in one integrated microfluidic chip. This is also thistopic the main innovation points. First, ammonia is absorbed with an acid solution; acidsolution mixed with alkaline solution, the ammonia gas is released, while excludinginterfering gases. Ammonia gas goes into liquid through diffusion film. Then it is injectedinto the cell and detected by absorbance method.In the experiments, the experimental conditions were optimized by the single factor. Inthe end, this method can achieve an effective concentration of ammonia, and eventuallycome to the absorbance of a linear regression fit. Some deficiencies in the paper aresummarized. For example, removing air bubbles interference, improving the accuracy ofdetection devices, software programming, These aspects remains to be further improved.