基于微气相色谱技术的含硫恶臭气体检测

Detection of sulfur containing odorous gas based on micro-gas chromatography technology

通过喷砂射流微细加工工艺与MEMS工艺,在Pyrex7740型硼硅玻璃表面进行刻蚀,得到400μm的微细通道,利用热压键合技术得到微型气相色谱柱。选择固定相CB-40(40%的苯基+60%的二甲基聚硅氧烷)对芯片内部进行涂敷,针对含硫的恶臭气体进行分离。并利用自制Tenax管式富集器对气体进行预浓缩,针对检测的含硫化合物与苯系物的恶臭气体提高了检测限。设计了自动进样系统与温度控制系统,并选取PID(Photoionization Detector)光离子化传感器作为终端传感器。选取典型的含硫恶臭物质与苯系物恶臭气体进行混合,实现了很好的分离,其中苯的检测限可以达到20×10^(-9),甲硫醚的检测限可以达到100×10^(-9)。

A 400 μm of micro-channel is prepared through etching Pyrex7740 borosilicate glass,based on sand blasting technology and MEMS technology. A mini-size gas chromatography column is then obtained by using hot press bonding technology. The stationary phase CB-40（ 40% phenyl compound ＋ 60% dimethylpolysiloxane） is selected to coat the inside of the chip for separation of sulfur-containing malodorous gases. The pre-concentration of gas is enhanced by the self-made Tenax tube concentrator. The detection limit is improved for the detection of odor-containing gases of sulfides and benzene series. The automatic sampling system and temperature control system are also designed. A photoionization sensor（ PID） is selected as the terminal sensor. Additionally,a typical sulfur-containing odorant is mixed with benzene-based malodorous gas. A good separation effect can be achieved. The detection limits of benzene and toluene are 20 × 10^-9,and the detection limit of hydrogen sulfide could reach 100 × 10^-9.