It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature mass spectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed a new radiofrequency...It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature mass spectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed a new radiofrequency field enhanced chemical ionization source(RF-ECI) with vacuum ultraviolet(VUV)lamp by coupling radiofrequency electric field and direct-current field together. The experiment results showed that the sensitivity of benzene, toluene, hydrogen sul fide and other compounds increased by 2–3 orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization(SPI). At the same time, the reagent ion of O_2^+realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp has inherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-offlight mass spectrometer(TOFMS) has a limit-ofdetection for H_2S as low as 0.0571 mg/m^3, and it is expected to be used widely in the field of on-site rapid analysis.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21375129 and 21675155)
文摘It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature mass spectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed a new radiofrequency field enhanced chemical ionization source(RF-ECI) with vacuum ultraviolet(VUV)lamp by coupling radiofrequency electric field and direct-current field together. The experiment results showed that the sensitivity of benzene, toluene, hydrogen sul fide and other compounds increased by 2–3 orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization(SPI). At the same time, the reagent ion of O_2^+realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp has inherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-offlight mass spectrometer(TOFMS) has a limit-ofdetection for H_2S as low as 0.0571 mg/m^3, and it is expected to be used widely in the field of on-site rapid analysis.
