热解析与催化发光联用技术测定空气中甲苯含量的方法研究

研究了甲苯在Y2O3粉体表面催化发光行为,发现基于这种催化剂的气体传感器对甲苯的检测具有较高灵敏度。在波长425nm处进行定量分析,催化发光强度与甲苯浓度在相当宽的范围内呈良好的线性关系,其线性范围为0.86—130mg/m3(r=0.9960);检出限为0.29mg/m3(信噪比=3)。对浓度为17.32mg/m3的甲苯气体平行测定了9次的发光强度,其相对标准偏差为5.4%。该传感器连续工作时间达85h以上,其发光信号没有明显下降,是一种长寿命的、性能稳定的气体传感器,并成功地实现了对空气中痕量甲苯的检测。

Study on Determination of Methyibenzene in the Air by the Combined Technique of Thermal Analysis and Catalytic Luminescence

Methylbenzene was catalytically oxidized by O2 in air over the surface of YzO3,which resulted in intensive chemiluminescence （CL）. The methylbenzene gas sensor based on this kind of CL was developed. The method for the determination of methylbenzene gas with the gas sensor using this catalyst had high sensitivity and good selectivity. Quantitative analysis was performed at the wavelength of 425nm. Under the optimal conditions,CTL intensity was directly proportional to the concentration of methylbenzene. The linear range was in the range of 0.86--130mg/m^3（r= O. 9960） with detection limit of 0. 29mg/m^3（the signal-to-noise ratio was 3）. The relative standard deviation was 5.4% （n = 9） for determinating of concentration of 17. 32mg/m^3 methylbenzenz gas. This gas sensor can work for more than 85h and is a durable and stable one which has been successfully used for real-time online determination of methylbenzene.