US3479798A - Method in the analysis of gases - Google Patents

Method in the analysis of gases Download PDF

Info

Publication number
US3479798A
US3479798A US3479798DA US3479798A US 3479798 A US3479798 A US 3479798A US 3479798D A US3479798D A US 3479798DA US 3479798 A US3479798 A US 3479798A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
gas
gases
chambers
carrier gas
mixture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Erik Ragnar Ryhage
Original Assignee
Erik Ragnar Ryhage
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J49/00Particle spectrometers or separator tubes
    • H01J49/02Details
    • H01J49/04Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components
    • H01J49/0422Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components for gaseous samples
    • H01J49/0427Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components for gaseous samples using a membrane permeable to gases
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02Column chromatography
    • G01N30/62Detectors specially adapted therefor
    • G01N30/72Mass spectrometers
    • G01N30/7206Mass spectrometers interfaced to gas chromatograph
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02Column chromatography
    • G01N30/84Preparation of the fraction to be distributed
    • G01N2030/8423Preparation of the fraction to be distributed using permeable separator tubes

Description

Nov. 25, 1969 E. R. RYHAGE 3,479,798

mswon IN THE ANALYSIS OF GASES Filed April 16, 1965 INVENTOR E fi/K RA G/VAR RYHAGE BY M 701202, 77M

7% ATTO 5Z5 United States Patent 0 M 3,479,798 METHOD IN THE ANALYSIS OF GASES Erik Ragnar Ryliage, Armfeltsgatan 5, Stockholm, Sweden Filed Apr. 16, 1965, Ser. No. 448,701 Claims priority, application Sweden, Apr. 21, 1964, 4,911/64; Apr. 23, 1964, 5,025/64; Sept. 25, 1964,

Int. Cl. 301d 13/02 US. Cl. 55-158 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a method in the analysis of gases and vaporized substances by means of a mass spectrometer connected to a gas chromatograph. More particularly, the invention relates to a method for separating the carrier gas from the gas mixture issuing from the'gas chromatograph in order to remove as much as possible of the carrier gas from the carried gas before the latter is introduced into the mass spectrometer.

The combination of a mass spectrometer and a gas chromatograph has proved a valuable tool for the analysis of gas mixtures and particularly mixtures of volatile organic compounds. However, the presence of the carrier gas, e.g. helium or hydrogen, in the gas mixture, while necessary in the gas chromatograph, is objectionable in the mass spectrometer. If the carrier gas is allowed to enter the ionization chamber of the mass spectrometer it is ionized along with the gases to be analysed, provided that normal ionization potentials are used, and the ions produced from the carrier gas may form the major part of the total ion current, so that the measurement of the ion current produced from the gases to be analysed is made impossible or uncertain.

Various means and methods have been devised to eliminate the adverse efiect of the presence of the carrier gas in the mass spectrometer, but even though such method and means are provided, the amount of carrier gas entering the mass spectrometer should be reduced to a minimum. A known method of achieving this end is based upon the fact that if a gas stream containing molecules or atoms of different weights is caused to expand, the lighter particles will collect in the peripheral parts of the stream while the heavier particles concentrate at the central part of the stream. Since the molecular weight of the carrier gas used in gas chromatography is consid: erably lower than that of the gases to be analysed, it is thus possible to separate the carrier gas from the gas mixture issuing from the gas chromatograph column by expanding the gas stream and providing an apertured diaphragm in the path of the expanded gas stream, the aperture having such size that it admits passage of the central portion of the stream only. The central portion which for the most part consists of the gas or gases to be analysed, is passed to the mass spectrometer, while the peripheral portion of the stream, which for the most part consists of the carrier gas, is deflected by the diaphragm and withdrawn from the system by some suitable means. However, this method suffers from the drawback 3,479,798 Patented Nov. 25, 1969 that either an insufficient amount of the carrier gas is removed or a relatively large amount of the carried gas is removed as well.

It is an object of the present invention to provide a method by which the carrier gas can be effectively separated from the gas mixture without any considerable loss of the carried substances.

According to the invention the mixture of carrier gas and carried substances issuing from the gas chromatograph is passed through a channel which is surrounded by a permeable material whose permeability to the carrier gas is considerably larger than its permeability to the carried substances. When the gas mixture is passing along this channel the carrier gas to a large extent diffuses through the surrounding material so that the gas arriving at the exit end of the channel contains little or no carrier gas. From the exit end of the channel the gas is passed on to the inlet of the mass spectrometer.

The material surrounding the said channel is formed into a tube-shaped body, and this body should be enclosed in a chamber provided with means for keeping the pressure outside the body at a lower value than the pressure in said channel in order to accelerate the diffusion of the carrier gas through the material.

The material used for separating the carrier gas from the carried substances may be such that it is permeable only to gases having very light molecules as for instance hydrogen and helium, while it is completely impermeable to gases having larger molecules. Certain metals, for instance gold, platinum and other metals belonging to the platinum group, and particularly palladium, in the form of thin sheets have this property and may be used for the purpose of the invention.

However, preferably the permeable material surrounding the gas fiow channel consists of porous or microporous material such as glass and similar inorganic thermoplastic materials, organic thermoplastic materials, ceramic materials, or porous metallic materials. The choice of material is determined by the required pore size, and this may vary within wide limits depending on the carrier gas to be used and the kind of substances to be analysed and also upon temperature and pressure and the velocity of the gas stream. Thus, in some instances the required pore size may be as large as 0.1 mm. and in other instances less than l0 mm., but usually the pore size should be between 10* and l()- mm. Thermoplastic organic and inorganic materials and ceramic material with mediumsized and large pores as well as porous metallic materials with relatively large pores are available on themarket. Materials having very fine pores can be made from a metal alloy by dissolving one of its constituents, the remaining constituents forming a porous material.

An apparatus for carrying out the invention will now be described with reference to the accompanying drawing which shows a longitudinal section of a tubing'connecting a gas chromatograph with a mass spectrometer. The gas chromatograph and the mass spectrometer may be of any conventional types and are not shown.

Referring now to the drawing, the tubing has an inlet 1 connected to the gas chromatograph column and an outlet 2 connected to the mass spectrometer. The direction of the gas flow through the tubing is indicated by arrows.

A cylindrical hollow member 3 of metal encloses two chambers 4 and 5 separated by a partition wall 6. A tube 7 of stainless steel is arranged coaxially within the'cylindrical member 3 and extends through the chambers 4 and 5 on either side of the partition wall 6. The wall of tube 7 is provided with perforations 8. A plurality of annular bodies 9 of a porous material is placed in a row within tube 7. The annular bodies 9 are separated from one another by thin annular metal washers 10. At both ends of the column formed by the bodies 9 there are placed bodies 11 of a non-porous material. The central openings in the members 9, 10 and 11 and a registering opening in the partition wall 6 form a channel 12. One end of the channel 12 is connected by a tube 13 to the inlet of the system and the other end of the channel is connected to the outlet end.

The chambers 4 and 5 are connected by exhaust tubes 14 and 15 respectively to vacuum pump means (not shown). Preferably the pump means are arranged to produce a higher degree of vacuum in chamber 5 than in chamber 4.

The device may also be provided with gas flow control means generally indicated at 16 and 17 in the figure.

When the mixture of carrier gas and carried substances is passed along channel 12 most of the carrier gas diffuses through the porous bodies 9 and enters the chambers 4 and 5 from where it is withdrawn through tubes 14 and 15. The carried substances, i.e. the gases to be analysed, do not diffuse through the bodies 9 to any large extent but are passed on to the mass spectrometer through outlet 2.

The separating eflFect and the rapidity of the separation can be increased by causing the gas stream to expand before or after it is introduced into the channel surrounded by the porous material. Such expansion can be brought about by giving the nozzle (tube 13 in'the drawing) through which the gas is introduced into the channel an appropriate form. This nozzle may also be made of a porous material. The expansion of the gas stream causes the lighter molecules of the gas mixture, i.e. the molecules of the carrier gas, to collect adjacent to wall of the channel whereby the diffusion of these molecules through the porous wall of the channel is increased. To improve the separation effect still further the gas stream can be subjected to expansion in two or more steps, the gas stream being compressed between the expansion steps.

While the principles of the invention have been described above in connection with specific apparatus, it is to be understood that this description is made only by way of example and not as a limitation of the scope of the invention.

What is claimed is:

1. A molecular separator or the like, comprising a housing; an inlet at one end of said housing and an outlet at the other end of said housing; a transverse partition in said housing dividing the space between said ends thereof into first and second chambers, said partition having a flow passage therethrough; apertured first and second conduit means respectively providing fluid communication between said inlet and one side of side flow passage and between the other side of said fiow passage and said outlet; a first adjustable valve means for regulating the flow of the gas mixture from said inlet into said first conduit means; a second valve means adjustable independently of the first valve means for regulating the flow of the mitxure through the flow passage in the transverse partition; barriers in said first and second conduit means configured to define passages for a gas mixture entering said separator through said inlet, said barriers being permeable to at least one selected gas in said mixture, whereby said gas can escape through said barriers and said apertured conduit means into said chambers whereby said gas can be separated from said mixture; and means for removing said gas from said chambers.

2. A molecular separator or the like, comprising a housing; an inlet at one end of said housing and an outlet at the other end of said housing; a transverse partition in said housing dividing the space between said ends .4 thereof into first and second chambers, said partition having a flow passage therethrough; apertured first and second conduit means respectively providing fluid communication between said inlet and one side of said flow passage and between the other side of said flow passage and said outlet; barriers in said first and second conduit means configured to define passages for a gas mixture entering said separator through said inlet, said barriers being permeable to at least one selected gas in said mixture, whereby said gas can escape through said barriers and said apertured conduit means into said chambers, whereby said gas can be separated from said mixture; means for maintaining the pressures in at least one of the first and second chambers lower than the pressure on the gas mixture flowing through the separator and for maintaining the pressure in one of said chambers lower than the pressure in the other of said chambers; and means for removing said gas from said chambers.

3. A molecular separator or the like, comprising a housing; an inlet at one end of said housing and an outlet at the other end of said housing; a transverse partition in said housing dividing the space between said ends thereof into first and second chambers, said partition having a fiow passage therethrough; apertured first and second conduit means respectively providing fluid communication between said inlet and one side of said flow passage and between the other side of said fiow passage and said outlet; barriers in said first and second conduit means configured to define passages for a gas mixture entering said separator through said inlet, said barriers being permeable to at least one selected gas in said mixture, whereby said gas can escape through said barriers and said apertured conduit means into said chambers, whereby said gas can be separated from said mixture, there being a plurality of barriers in each of said conduit means, and said barriers being separated by non-porous members; non-porous bodies adjacent the upstream barrier in the first conduit means and adjacent the downstream barrier in the second conduit means; and means for removing said gas from said chambers.

4. The separator of claim 3, wherein the barriers are fabricated of a porous material and wherein the pore size is in the range of about 10- to about 10- mm.

References Cited UNITED STATES PATENTS 1,174,631 3/1916 Snelling 55-16 2,924,630 2/1960 Fleck 55--16 3,104,960 9/1963 Chamberlin 55-158 3,239,996 3/1966 Huffman 5516 3,246,449 4/1966 Stern et a1. 5516 2,892,508 6/1959 Kohman et al. 1832 2,627,933 2/ 1953 Teter 1832 FOREIGN PATENTS 1,366,968 6/ 1964 France.

794,834 5/1958 Great Britain.

OTHER REFERENCES Mass Spectrometry of Terpenes, R. Ryhage, E. von

Sydow, in acta chem. scand 17, 1963, pp. 2025-2035.

R. Ryhage, Analytical Chemistry, vol. 36 (4), pp. 759 to 764.

RICHARD C. QUEISSER, Primary Examiner VICTOR J. T 0TH, Assistant Examiner US. Cl. X.R. 7323 .1

US3479798A 1964-04-21 1965-04-16 Method in the analysis of gases Expired - Lifetime US3479798A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
SE491164 1964-04-21
SE502564 1964-04-23
SE1149864 1964-09-25

Publications (1)

Publication Number Publication Date
US3479798A true US3479798A (en) 1969-11-25

Family

ID=27354371

Family Applications (1)

Application Number Title Priority Date Filing Date
US3479798A Expired - Lifetime US3479798A (en) 1964-04-21 1965-04-16 Method in the analysis of gases

Country Status (2)

Country Link
US (1) US3479798A (en)
GB (1) GB1065131A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3589171A (en) * 1969-08-25 1971-06-29 California Inst Of Techn Gas analysis system and palladium tube separator therefor
US3712111A (en) * 1968-07-10 1973-01-23 Vanan Ass Flow control for gas analyzing apparatus
US4791292A (en) * 1986-04-24 1988-12-13 The Dow Chemical Company Capillary membrane interface for a mass spectrometer
US4951503A (en) * 1990-01-23 1990-08-28 Niagara Mohawk Power Corporation Method and apparatus for determining the heating value of a gaseous fuel
CN105372362A (en) * 2015-11-27 2016-03-02 大连理工大学 Vacuum keeper for a gas chromatography-mass spectrometer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8619239D0 (en) * 1986-08-06 1986-09-17 British American Tobacco Co Gas chromotography

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1174631A (en) * 1914-09-17 1916-03-07 Walter O Snelling Apparatus for separating gases.
US2627933A (en) * 1947-06-28 1953-02-10 Sinclair Refining Co Aerogel diffusion unit
GB794834A (en) * 1955-10-05 1958-05-14 Erwin Willy Albert Becker Process for the separation of gaseous or vaporous substances, more especially isotopes
US2892508A (en) * 1957-04-17 1959-06-30 Bell Telephone Labor Inc Separation of gases by diffusion
US2924630A (en) * 1957-06-28 1960-02-09 Union Oil Co Fluid diffusion fractionation
US3104960A (en) * 1960-05-24 1963-09-24 Eitel Mccullough Inc Gas flow apparatus
FR1366968A (en) * 1963-06-07 1964-07-17 Commissariat Energie Atomique Diffuser for gas separation
US3239996A (en) * 1963-03-18 1966-03-15 Humble Oil & Refining Company Method of separating helium from other constituents of natural gas
US3246449A (en) * 1959-06-09 1966-04-19 Union Carbide Corp Recovery of helium

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1174631A (en) * 1914-09-17 1916-03-07 Walter O Snelling Apparatus for separating gases.
US2627933A (en) * 1947-06-28 1953-02-10 Sinclair Refining Co Aerogel diffusion unit
GB794834A (en) * 1955-10-05 1958-05-14 Erwin Willy Albert Becker Process for the separation of gaseous or vaporous substances, more especially isotopes
US2892508A (en) * 1957-04-17 1959-06-30 Bell Telephone Labor Inc Separation of gases by diffusion
US2924630A (en) * 1957-06-28 1960-02-09 Union Oil Co Fluid diffusion fractionation
US3246449A (en) * 1959-06-09 1966-04-19 Union Carbide Corp Recovery of helium
US3104960A (en) * 1960-05-24 1963-09-24 Eitel Mccullough Inc Gas flow apparatus
US3239996A (en) * 1963-03-18 1966-03-15 Humble Oil & Refining Company Method of separating helium from other constituents of natural gas
FR1366968A (en) * 1963-06-07 1964-07-17 Commissariat Energie Atomique Diffuser for gas separation

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3712111A (en) * 1968-07-10 1973-01-23 Vanan Ass Flow control for gas analyzing apparatus
US3589171A (en) * 1969-08-25 1971-06-29 California Inst Of Techn Gas analysis system and palladium tube separator therefor
US4791292A (en) * 1986-04-24 1988-12-13 The Dow Chemical Company Capillary membrane interface for a mass spectrometer
US4951503A (en) * 1990-01-23 1990-08-28 Niagara Mohawk Power Corporation Method and apparatus for determining the heating value of a gaseous fuel
CN105372362A (en) * 2015-11-27 2016-03-02 大连理工大学 Vacuum keeper for a gas chromatography-mass spectrometer

Also Published As

Publication number Publication date Type
GB1065131A (en) 1967-04-12 application

Similar Documents

Publication Publication Date Title
US3545931A (en) Ammonia analysis system
US3712111A (en) Flow control for gas analyzing apparatus
US3350846A (en) Separation of hydrogen by permeation
US3344582A (en) Irreversible hydrogen membrane
Giddings Role of Column Pressure Drop in Gas Chromatographic Resolution.
US3598728A (en) Membrane-moderated separation apparatus and process
US2773561A (en) Silver-palladium film for separation and purification of hydrogen
Bertsch et al. Trace analysis of organic volatiles in water by gas chromatography-mass spectrometry with glass capillary columns
US5235843A (en) Method and apparatus for analyzing volatile chemical components in a liquid
US2961062A (en) Large surface area hydrogen permeation cell
US5281397A (en) Adjustable open-split interface for a gas chromatograph and a mass spectrometer
US3926561A (en) Gas analysis employing semi-permeable membrane
US2609059A (en) Mass diffusion process and apparatus
Eustache et al. Separation of aqueous organic mixtures by pervaporation and analysis by mass spectrometry or a coupled gas chromatograph—mass spectrometer
Sengupta et al. Separation of solutes from aqueous solutions by contained liquid membranes
US5583281A (en) Microminiature gas chromatograph
US4791292A (en) Capillary membrane interface for a mass spectrometer
US2159434A (en) Process for concentrating hydrocarbons
US5481110A (en) Thin film preconcentrator array
US3589171A (en) Gas analysis system and palladium tube separator therefor
Callear et al. THE APPLICATION OF GAS–LIQUID PARTITION CHROMATOGRAPHY TO PROBLEMS IN CHEMICAL KINETICS
US4445038A (en) Apparatus for simultaneous detection of positive and negative ions in ion mobility spectrometry
US3772909A (en) Apparatus for analyzing environmental gases
US5108468A (en) Switching system for a multidimensional gas chromatograph
US3538744A (en) Chromatography apparatus