紫外离子迁移谱在线监测芳香族化合物

利用自制紫外离子迁移谱仪,在迁移电场为311V/cm、离子门开门时间0.2ms和室温的条件下,测定了空气中的苯、甲苯、二甲苯以及萘、芴、蒽、1,2,3-三氯苯、5-氯苯酚等芳香族化合物,得到苯的校正迁移率为1.86cm2V-1s-1,且校正迁移率随着分子量的增大而减小。仪器对苯的检出限达到1mg/m3;线性范围达到4个数量级;响应时间小于10s。研究发现,电场强度增大有利于提高仪器的灵敏度,测定时载气流速100mL/min,迁移气流速300mL/min时,效果最佳。

On-line Detection of Aromatic Substances Using Ultraviolet Ion Mobility Spectrometry

Benzene,toluene,xylene,naphthalene,fluorine,anthracene,1,2,3-trichlorobenzene and 5-chlorophenol in air were detected by the home-made UV ion mobility spectrometer.The measurements were made under the conditions of room temperature,drift electric field 311 V/cm and shutter opening time 0.2 ms.The mobility of benzene is 1.86 cm2V-1s-1,which decreased with the increase of the mass of the compounds.For benzene,the detection limits was 1 mg/m3 and the linear range reached 4 orders of magnitude and the response time was less than 10 seconds.The influences of electrical field and the flow rate of drift gas and carrier gas to the signal intensity were investigated.The sensitivity was improved with higher electric field and the gas flow rate for sample gas and drift gas were 100 mL/min and 300 mL/min,respectively.