Development Of Environmental Pollution Gas Detection System Based On Microfluidic Chip

Environmental mixed gas pollutants not only have serious impact on the ecological environment,but also cause great harm to human health.So it is urgent to detect and control Environmental mixed gas pollutants.According to the characteristics of mixed environmental pollutant gases,this paper establishes the principle of chromatography to separate mixed gases.The separated single gas component is detected by photoionization detector,so as to realize the concentration measurement of odor.Firstly,the detection system principle of chromatographic separation was introduced.According to the principle of chromatographic separation,the simulation experiment of chromatographic separation is carried out by COMSOL software,proveing the feasibility of separation.Secondly,the processing technology of chromatographic column of microfluidic chip is introduced,including the selection of borosilicate glass as matrix material,the layout of S-shaped channel,we used sand flow etching method and combination of anode and hot-pressing bonding method.The chromatographic channel of the length 4.7 m,width 100 microns to 400 microns was designed.Microfluidic chip and testing unit mode selection of joint sealant joint solution,it is simple operation and good sealing.Then,according to the requirements of environmental pollution gas detection,light detector ionization detector was as the mixed gas detection system.The optical ionization detector working principle was studied,The light ionization electrode structure was designed.The opper foil of two different size of 3 mm and 7 mm width was the electrode to stimulate vacuum ultraviolet lamp.The micro optical ionization detector integrated into miniature chromategraphic column chip,the integration of the separate module and detection module is realized.Finally,the gas separation system was used to separate the odor mixture.the stability and repeatability of the developed photoionization detector were tested.By changing the parameters of flow and temperature test environment the affecting factors on the system were analyzed.And according to the different test conditions for validation,the temperature in 45 to 55 ℃ and 0.08 to 0.12 MPa pressure was the best experimental condition,the mixed pollution gas separation experiment was carried out,more than 3 kinds of material separation,separating degree can reach above 1.5,separation gas concentration is 500 ppb.