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EP1093151A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Mass spectrometer, mass spectrometry, and monitoring system

Assignee: Hitachi Ltd
•
Filing: 2000-09-15
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Granted: —
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Expires: 2020-09-15
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Abstract

Abstract An ion source using a corona discharge for ionising a sample gas at high efficient is provided. The corona discharge is generated at the tip end of a needle electrode by the application of high voltage. The direction in which the sample gas introduced into the corona discharge region and the direction in which ions are drawn by the corona are substantially opposite, thereby improving the efficiency of ionisation and maintaining a stable discharge for a long period.

Inventors

  • 👤 Minoru Sakairi
  • 👤 Yuichiro Hashimoto
  • 👤 Masuyoshi Yamada
  • 👤 Masao Suga
  • 👤 Kyoko Kojima

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-07 07:20
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/16; H01J49/168; H01J49/04; H01J49/0422; G; G01; G01N; G01N30/00; G01N30/02; G01N30/62; G01N30/72; G01N30/7233; G01N30/724

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 92 words
A mass spectrometer comprising: a first chamber with a needle electrode arranged therein; a first opening portion for introducing ions generated in said first chamber into a mass spectrometric portion; and a second opening portion for supplying a sample gas, said second opening portion being located so that the angle formed by the direction connecting the tip end of said needle electrode and said first opening portion and the direction connecting the centre of said second opening and said tip end of said needle electrode is less than or equal to 90°.
Claim 2
Dependent Claim 18 words
The spectrometer of claim 1, wherein ionisation is performed within a corona discharge region by said needle electrode.
Claim 3
Dependent Claim 25 words
The spectrometer of claim 1 or 2, wherein a drift region of the ions by an electric field is located adjacent said corona discharge region.
Claim 4
Dependent Claim 52 words
A mass spectrometer comprising: a first chamber with a needle electrode arranged therein, a sample gas being ionised by a discharge in said first chamber; an opening portion for discharging the sample gas from said first chamber, said opening portion being formed on the side of the root of said needle electrode.
Claim 5
Dependent Claim 17 words
The spectrometer of claim 1, wherein said needle electrode is covered with an insulator or a plating.
Claim 6
Dependent Claim 40 words
The spectrometer of claim 1, wherein the distance between a wall member defining said first chamber and said needle electrode is greater than the distance between the tip end of said needle electrode and the centre of said first opening.
Claim 7
Dependent Claim 28 words
The spectrometer of claim 1, wherein said needle electrode is covered with an insulator, and said first chamber is defined by a wall member formed of an insulator.
Claim 8
Dependent Claim 17 words
The spectrometer of claim 1, including a monitor for measuring the current flowing through said needle electrode.
Claim 9
Dependent Claim 91 words
The spectrometer of claim 1, further including a first partitioning wall having said first opening portion; a second chamber formed in said first chamber via said first partitioning wall; and a second partitioning wall having a third opening portion for introducing ions from said second chamber into said mass spectrometric portion; wherein the absolute value of the voltage applied to said needle electrode is greater than that of the voltage applied to said first partitioning wall, which in turn is greater than that of the voltage applied said second partitioning wall.
Claim 10
Dependent Claim 148 words
A mass spectrometer having an ion source for ionising a sample gas by generating a corona discharge at the tip end of a needle electrode by applying a high voltage to said needle electrode, comprising: a first chamber in which said needle electrode is arranged; a partitioning wall having an opening portion for introducing ions generated in said first chamber into a mass spectrometric portion, said sample gas supplied to said first chamber flowing in a direction which forms an angle greater than or equal to 90° with the direction connecting the tip end of said needle electrode; a first drift region adjacent said first chamber via said partitioning wall and causing drift of the ions by an electric field; a second drift region provided adjacent said first drift region for introducing a reaction gas into said first drift region and introducing the sample gas for performing measurement.
Claim 11
Dependent Claim 139 words
A mass spectrometer comprising: a first chamber for ionising a sample gas by discharge by the application of a voltage to a needle electrode; a first opening portion for taking out the ions ionised in said first chamber; a second chamber connected to a first supply pipe for supplying the sample gas through a second opening portion different from said first opening portion; a third opening portion arranged at a portion of said second chamber at a position different from said first or second opening portion; a second supply pipe for supplying said sample gas through said third opening; a third chamber communicating with said first chamber for receiving said sample gas through said second supply pipe; and a mass spectrometric portion for analysing the mass weight of the ions passing through a fourth opening of said third chamber.
Claim 12
Dependent Claim 124 words
An ion source comprising: an electrode rod; a first chamber housing said electrode rod; a first opening portion for inserting said electrode rod; a second opening portion for introducing a sample gas into said first chamber at a position opposite said electrode rod; a third opening portion for discharging gas from said first chamber on the side of said first opening portion; an electrode plate in contact with said second opening portion and having a fourth opening portion; a second chamber defined by said electrode plate; a fifth opening portion provided at a position of said second chamber opposite said electrode plate for discharging ionised sample gas; and a sixth opening for introducing sample gas between said electrode plate and said fifth opening portion.
Claim 13
Dependent Claim 40 words
A mass spectrometer comprising: the ion source of claim 12; an electrostatic lens separating neutral particles from an ion flow obtained from said ion source; and an ion trapping type mass spectrometer for analysing the ions from said electrostatic lens.
Claim 14
Dependent Claim 189 words
An ion source comprising: an electrode rod; a first chamber housing said electrode rod; a first opening portion for inserting said electrode rod; a second opening portion for introducing a sample gas into said first chamber at a position opposite said electrode rod; a third opening portion discharging gas from said first chamber at the side of said first opening portion; a first electrode plate in contact with said second opening portion and having a fourth opening portion; a second chamber defined by said first electrode plate; a second electrode plate with a fifth opening portion provided at a position of said second chamber opposite said first electrode plate; a third chamber defined by said second electrode plate; a sixth opening portion provided at a position of said third chamber opposite said second electrode plate for discharging an ionised sample; a seventh opening for introducing one of a first gas and a sample gas between said first electrode and said second electrode plate; and an eighth opening portion for introducing the other one of said first gas and sample gas between said second electrode and said sixth opening portion.
Claim 15
Dependent Claim 100 words
A measuring system having a mass spectrometer and an ion source performing ionisation of a sample gas by causing a corona discharge at the tip end of a needle electrode by applying a high voltage, restricting the signal amplitude with respect to the mass number of NO 3 generated by O 2 generated by a negative corona discharge in a corona discharge region by restricting the NO 3 generating reaction by reaction of O 2 and N 2 for measuring a fine component in a gas selected from chlorophenols, dioxins, chlorobenzenes, chlorophenols, hydrocarbons, nitro compounds a precusor of said dioxins.
Claim 16
Dependent Claim 70 words
A measuring system having a mass spectrometer and an ion source performing ionisation of a sample gas by causing a corona discharge at the tip end of a needle electrode by applying a high voltage, measuring the signal amplitude of dichlorophenol with respect to the mass number of NO 3 generated as an intermediate by O 2 by restricting the signal amplitude to a value smaller than that of dichlorophenol.
Claim 17
Dependent Claim 80 words
A monitoring system comprising: an exhaust passage for discharging flue gas of combustion; a sampling pipe collecting said flue gas in a part of said exhaust passage; a filter for removing unnecessary components from the gas from said sampling pipe; and a mass spectrometer for receiving the gas passing through said filter from the mass spectrometric side on downstream side by discharge, analysing the gas in said mass spectrometer, and monitoring generated dioxins on the basis of the analysis result.
Claim 18
Dependent Claim 59 words
An incinerator comprising: a mass spectrometer for receiving gas passing through a filter from a mass spectrometric side on downstream side by discharge; and a monitoring system for analysing in said mass spectrometer and monitoring generated dioxins on the basis of the analysis result, for controlling the operation on the basis of the analysis result from said mass spectrometer.
Claim 19
Dependent Claim 41 words
An explosive detector comprising: a probe for sampling a gas; the mass spectrometer of claim 1, wherein said first chamber receives the sample gas from said probe; and a display for displaying a result of judgement made by said mass spectrometer.
Claim 20
Dependent Claim 48 words
An explosive detector comprising: an inspection object scanning portion for inspecting an object; a suction device for sucking a sample gas from said inspection object; and the mass spectrometer of claim 1 for making a judgement, wherein said first chamber receives the sample gas from said suction device.
Claim 21
Dependent Claim 24 words
The detector of claim 20, wherein said inspection object scanning portion samples said sample gas by moving said inspection object on a movable base.

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