傅里叶变换表面离化离子迁移率谱仪

表面离化离子迁移率谱仪是一种可用于痕量含氮有机污染物检测的装置,具有灵敏度高、响应快等特点。文中尝试将傅里叶变换技术应用于表面离化离子迁移率谱仪,以提高表面离化离子利用率,从而提高仪器的信噪比。以三乙胺检测为例,比较了线性扫频和步进扫频两种工作模式。结果表明,与传统单周期扫描法相比,傅里叶变换表面离化离子迁移率谱仪的信噪比提高约3～5倍;线性扫频模式有更短的检测周期和较高的信噪比;在相近信噪比条件下,线性扫频模式傅里叶变换离子迁移率谱仪的扫描周期仅是多周期扫描信号平均法用时的1/4,因而更适用于快速检测。

Fourier Transform Surface Ionization Ion Mobility Spectrometer

Surface ionization ion mobility spectrometer(SI-IMS)has the advantages of high sensitivity and short response time,which is recognized as one of the best devices for the detection of trace level nitrogenous organic contaminants.The Fourier transform method was applied to a SI-IMS to improve the signal-to-noise ratio(SNR)of the device.It has been found that the experimental SNR of the Fourier transform surface ionization ion mobility spectrometer(FT-SI-IMS)is enhanced by 3 to 5 times compared with that of the single-scan process.The performance of FT-SI-IMS in linear frequency sweep mode and step frequency sweep mode was compared through the analysis of trace tri-ethylamine.Collection period of the linear frequency sweep mode is shorter and the SNR is higher.To achieve the same SNR,the collection period of the linear frequency sweep mode is only about 1/4 of the signal-averaged process.