Online mass spectrum sample introduction device with tubular film inside ionization source

Abstract

The invention designs an online mass spectrum sample introduction device with a tubular film inside an ionization source. The sample introduction device comprises the tubular film, heating lamps, a sample introduction metal tube, a particle filter screen and emergency cut-out solenoid valves. A nonporous compact polydimethylsiloxane tubular film serves as the tubular film. The tubular film is directly arranged in an ionized region. The heating lamps arranged on the outer sides of the tubular film are used as film heating devices. Metal capillary tubes are connected with two ends of the tubular film and are respectively used as a sample introduction inlet and a sample introduction outlet. An air exhausting opening is arranged on the side wall of the cavity of the ionized region. The air exhausting opening is provided with an adjustable valve to adjust the vacuum degree of the ionized region. Arrayed tubular films can be used in the ionized region to facilitate a large amount of sample introduction. The device improves the transmittance of samples in the film and ionization efficiency of the samples.

Description

technical field [0001] The invention belongs to a mass spectrometry instrument, in particular to a device in which a tubular membrane is directly placed in an ionization region and a heating lamp is used to heat the surface of the membrane. The device can overcome the disadvantage of the large diffusion loss of the sample that is enriched first and then injected through a capillary tube by common membrane injection. Under the action of pressure difference inside and outside the membrane and heating, the tubular membrane sampling device in the ionization source allows the analysis sample to quickly pass through the membrane and be directly ionized by the ionization source on the surface of the membrane. The device improves the permeation rate of the sample in the membrane and the ionization efficiency of the sample. Background technique [0002] Membrane sampling is widely used as a mass spectrometry sampling device. The membrane mainly plays the role of separating, enrichi...

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Problems solved by technology

[0003] Ordinary sheet-shaped membrane sampling device, due to the need to ensure the vacuum degree of the mass spectrometer, the area of ​​the sheet-shaped membrane is required to be small enough, resulting in a small injection volume of the analysis sample, and the sheet-shaped membrane is thin and easy to break

However, the ordinary tubular membrane sampling device has a thick membrane wall, and the response time of the analysis sample on the membrane is relatively long, resulting in a serious memory effect of the analysis sample on the membrane, so it is not conducive to the rapid online detection of environmental samples.

In addition, the analysis sample is enriched through the membrane and then injected through the capillary. During this process, the analysis sample will have a part of the diffusion loss, which will affect the analysis results.

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