Research on Detection of Hydrogen Sulfide by High field Asymmetric Waveform Ion Mobility Spectrometry Based on Water Doping

KeyWord:high field asymmetric waveform ion mobility spectrometry(FAIMS)  waterdoping  detection limit  resolution

Abstract:

      High field asymmetric waveform ion mobility spectrometry(FAIMS) is a chip level rapid analysis technique with high sensitivity.Its characteristics under atmospheric pressure make it easily affected by the environment,of which the humidity of the gas is a significant factor.The variation of humidity caused change of the reaction mechanism of ions in the migration zone and change of the migration process.A method based on FAIMS was developed for the quantitative detection of trace hydrogen sulfide under dry conditions,and the linear range and regression equation of the detection at DF=33% were determined.Effects of different moisture contents on the detection of hydrogen sulfide by FAIMS were investigated by using the PTFE tube penetration effect and setting the water bath temperature at 40-90 ¡æ,while the effects of doped moisture on the peak value,compensation voltage,and resolution were studied by examining the FAIMS characteristic spectra and ionic peaks of hydrogen sulfide under different humidity.Results showed that FAIMS was clearly visible for the detection of hydrogen sulfide,and could accurately locate its characteristic ion peak.With the increase of moisture in the gas,the peak values of the product ions under different separation electric fields increased,indicating that the increase in humidity improved the sensitivity,to a certain extent.The detection limit at DF=35% was 1.43¡Á10-3 mg/m3.