Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J49/00—Particle spectrometers or separator tubes
  • H01J49/02—Details
  • H01J49/04—Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components
  • H01J49/0459—Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components for solid samples

Definitions

• the invention belongs to a mass spectrometer, in particular to a device in which a tubular film is placed directly in an ionization zone and a heating lamp is used to heat the surface of the film.
• the device can overcome the disadvantage that the diffusion of the sample by the ordinary membrane injection is first enriched and then the sample is injected by the capillary.
• the tubular membrane sampling device in the ionization source rapidly passes the analysis sample through the membrane under the pressure difference between the inside and outside of the membrane and is directly ionized by the ionization source at the membrane surface.
• the device increases the rate of transmission of the sample in the membrane and the ionization efficiency of the sample. Background technique
• Membrane injection is widely used as a mass spectrometry injection device.
• the membrane primarily serves to separate, enrich, and serve as a medium for isolating the atmospheric environment from the mass spectrometry vacuum. Since the polydimethylsiloxane film has selective permeability to different substances, volatile and semi-volatile organic substances can penetrate the film well. Therefore, the application of volatile and semi-volatile organic pollutants in an online analytical environment is very extensive.
• the sheet-like film sampling device since the requirement of the mass spectrometer vacuum degree is required, the sheet-like film area requirement is sufficiently small, and the injection amount of the analysis sample is small, and the sheet-like film is thin and easy to be broken.
• the ordinary tubular membrane injection device due to the thick film wall, the ordinary tubular membrane injection device has a long response time on the membrane, which results in a serious memory effect on the membrane, which is not conducive to rapid on-line detection of environmental samples.
• the analysis sample is enriched by the membrane and then subjected to capillary injection. During this process, the sample will have a part of the diffusion loss, which will affect the analysis results.
• the present invention designs an in-line mass spectrometry ionization source tubular film sampling device, which directly places the tubular film in the ionization zone, and the tubular film can be stretched 1-5 times in the axial direction, and then stretched.
• the rear tubular film can effectively reduce the wall thickness of the tubular film.
• the vacuum state of the mass spectrometer causes a large pressure difference between the inside and outside of the tubular film, and the sample can quickly permeate through the membrane.
• the sample can be ionized by the ionization source immediately after passing through the membrane, overcoming the diffusion loss of the analytical sample in other membrane mounting methods.
• the heat lamp accelerates the desorption of analytes from the membrane surface.
• the arrangement of a plurality of tubular membranes in the array can increase the injection volume, so the device can increase the rate of penetration of the sample in the membrane and improve the ionization efficiency. Summary of the invention
• An on-line mass spectrometry ionization source internal stretch film sampling device comprises an ionization zone, a tubular membrane is placed in the ionization zone, a metal capillary is connected at both ends of the tubular membrane as a sampling inlet and an outlet, and a particle filter is added before the sampling inlet, the upper end of the ionization zone
• the ionization source and the heating lamp are placed in the opening, and the emergency cut-off solenoid valve is installed on the inlet and the outlet of the injection metal capillary, and the vacuum valve is used to adjust the vacuum degree of the ionization zone.
• a peristaltic pump is arranged at the front end of the sampling inlet to feed the liquid sample into the tubular film, and is discharged from the outlet; when the gas sample is injected, an air pump is arranged at the front end of the sampling inlet to feed the gas sample into the tubular film. With the outlet discharge, a cyclic injection can be set when the analysis sample is small.
• the tubular membrane material is a polydimethylsiloxane membrane, which is a semipermeable membrane which can be stretched 1-5 times in the axial direction, and the tubular membrane after stretching can effectively reduce the tubular membrane. Wall thickness. A heat lamp is used as the film heating device.
• the tubular membrane is placed directly in the ionization zone, and a large pressure difference is formed inside and outside the tubular membrane by utilizing the mass spectrometry vacuum state and the atmospheric pressure state of the inner wall of the tubular membrane. Under the action of the pressure difference, the sample rapidly passes through the membrane and is directly ionized by the ionization source.
• the heating lamp can accelerate the desorption of the sample on the outer wall of the tubular membrane.
• the tubular membrane is placed directly in the ionization zone, and the vacuum conditions of the mass spectrometer are used to form a large pressure difference between the inner and outer sides of the membrane, and the diffusion rate of the sample on the membrane is accelerated.
• the tubular film stretched 1-5 times can reduce the thickness of the membrane wall and effectively reduce the response time of the analytical sample on the membrane.
• the ionization source is directly irradiated on the membrane so that the sample is ionized at the surface of the membrane, which improves the ionization efficiency of the sample.
• the tubular membrane in the ionization zone can use an array of tubular membranes to facilitate high-flow injection and improve sample sensitivity.
• a heating lamp is installed in the ionization zone to heat the outer surface of the tubular membrane, so that the sample is quickly desorbed from the membrane surface.
• the tubular membrane sampling device in the ionization source can realize continuous online detection of environmental samples.
• FIG. 1 is a schematic view showing the structure of a tubular film sampling device for use in an on-line mass spectrometry ionization source according to the present invention.
• FIG. 2 is a schematic view showing the injection of a film into an array tubular film in the apparatus of the present invention. detailed description
• the present invention provides a novel ionization source inner tubular membrane sampling device.
• the present invention is applied to a mass spectrometer, wherein 1 is a tubular membrane, 2 is a sampling inlet, 3 is a sampling outlet, 4 is a particle filter, 5 is a sampling metal capillary, 6 is an emergency cutting solenoid valve, and 7 is heating.
• Lamp is the ionization source
• 9 is the repeller plate
• 10 is the ionization zone
• 11 is connected to the mass analyzer interface
• 12 is the adjustment ionization zone vacuum valve.
• the front end of the sampling inlet 2 is provided with a peristaltic pump to send the liquid sample into the tubular membrane 1 and discharged from the sampling outlet 3; when the gas sample is taken, the sampling end of the sampling inlet 2 is provided with an air pump to feed the gas sample into the stretch tubular membrane 1 , discharged from the sampling outlet 3.
• An online mass spectrometry ionization source tubular film sampling device is disposed in a mass spectrometer ionization source, and the tubular film is directly placed in an ionization region of the mass spectrometry ionization source, and two ends of the tubular membrane are respectively connected with a metal capillary tube, and the metal capillary tube extends from the cavity of the mass spectrometry ionization source Out of the mass spectrometry ionization source cavity, the metal capillaries at both ends of the tubular membrane serve as sampling inlets and outlets respectively; a particle filter mesh is arranged in the metal capillary at the sampling inlet; and the metal capillary tubes at the sampling inlet and outlet are respectively provided with emergency cutoff Solenoid valve; a heating lamp is mounted outside the tubular membrane of the ionization zone in the mass spectrometry ionization source.
• the tubular membrane is placed directly in the ionization zone to increase the permeability of the sample on the membrane, and the sample is permeated through the membrane on the membrane surface. Direct ionization by the ionization source increases the ionization efficiency of the sample.
• a sample is sent to a stretched tubular membrane using a peristaltic pump or an air pump, and a particulate filter is added in front of the inlet to remove particulate matter from the sample to protect the membrane device.
• the tubular film used in the present invention is a polydimethylsiloxane film, which is a semi-permeable film, which is stretched by 3 times and used, and the thickness of the tubular film after stretching is effectively reduced, and the sample can be reduced. Response time on the membrane. It is also possible to use an array of tubular membranes for tubular membranes to facilitate high-flow injections, improving analyte detection sensitivity.
• the film is characterized in that inorganic substances such as nitrogen and oxygen in water and air are hard to penetrate the film, and volatile and semi-volatile organic pollutants easily pass through the film.
• the sample is passed through the particle filter through the sampling port and into the tubular film.
• a cyclic injection can be used.
• Volatile and semi-volatile organic pollutants pass through the membrane rapidly under the pressure difference inside and outside the membrane, and are immediately ionized by the ionization source, and enter the mass analyzer under the action of the repeller plate to be analyzed and detected.
• An emergency shut-off solenoid valve is installed at both the tubular membrane sampling inlet and outlet. When the membrane is in an emergency such as a rupture, the mass spectrum will change rapidly. At this time, the emergency cut-off solenoid valve will automatically close and protect the mass spectrometer.

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• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
• Sampling And Sample Adjustment (AREA)

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Citations (3)

• 2012
  • 2012-07-05 CN CN201210234534.1A patent/CN103531431B/zh active Active
  • 2012-09-21 WO PCT/CN2012/081768 patent/WO2014005377A1/fr not_active Ceased

Patent Citations (3)

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