US3887280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analytical apparatus and method of analysis
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1973-04-02
•
Granted: 1975-06-03
•
Expires: 1993-04-02
Abstract
Abstract Elemental analyses of carbon-containing samples are determined from the radiation emitted by them in a plasma which contains a scavenger for carbon.
Inventors
- 👤 William Ronald Mclean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:32
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/62; G01N30/64; G01N30/68; G01N21/00; G01N21/62; G01N21/71; G01N21/73; G01N33/00; G01N33/26; G01N33/28
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
51 words
A METHOD OF ANALYSIS WHICH COMPRISES INTRODUCING A CARBOB-CONTAINING SAMPLE TO A PLASMA IN THE PRESENCE OF HELIUM AND A CARBON LAY-DOWN SUPPRESSING AMOUNT OF A SCAVENGER FOR CARBON, SAID SCAVENGER BEING INTRODUCED SEPARATELY BEFORE THE SAMPLE DISSOCIATED, RESULVING RADIATION EMITTED BY THE PLASMA ACCORDING TO ITS FREQUENCY, DETECTING THE INTEN-
Claim 2
Independent Claim
51 words
A METHOD OF ANALYSIS WHICH COMPRISES INTRODUCING A CARBOB-CONTAINING SAMPLE TO A PLASMA IN THE PRESENCE OF HELIUM AND A CARBON LAY-DOWN SUPPRESSING AMOUNT OF A SCAVENGER FOR CARBON, SAID SCAVENGER BEING INTRODUCED SEPARATELY BEFORE THE SAMPLE DISSOCIATED, RESULVING RADIATION EMITTED BY THE PLASMA ACCORDING TO ITS FREQUENCY, DETECTING THE INTEN-
Claim 3
Independent Claim
73 words
A method of analysis which comprises introducing a carbon-containing sample to a plasma in the presence of helium and a carbon lay-down suppressing amount of a scavenger for carbon, said scavenger being introduced separately before the sample is dissociated, resolving radiation emitted by the plasma according to its frequency, detecting the intensity of radiation characteristic of an element and determining the quantity of the element present from the intensity of radiation so detected.
Claim 4
Independent Claim
73 words
A method of analysis which comprises introducing a carbon-containing sample to a plasma in the presence of helium and a carbon lay-down suppressing amount of a scavenger for carbon, said scavenger being introduced separately before the sample is dissociated, resolving radiation emitted by the plasma according to its frequency, detecting the intensity of radiation characteristic of an element and determining the quantity of the element present from the intensity of radiation so detected.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 1 wherein oxygen is the scavenger and the plasma contains 0.01 to 10% of oxygen expressed as atoms.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 1 wherein nitrogen is the scavenger and the plasma contains 0.03 to 30% of nitrogen expressed as atoms.
Claim 7
Dependent Claim
24 words
A method as claimed in claim 2 wherein the maximum concentration of carbon compounds is sufficient to provide one carbon atom per oxygen atom.
Claim 8
Dependent Claim
27 words
A method as claimed in claim 3 wherein the maximum concentration of carbon compounds is sufficient to provide at most one carbon atom per 3 nitrogen atoms.
Claim 9
Dependent Claim
19 words
A method as claimed in claim 1 wherein the pressure of the plasma is 10 8 to 2 bars.
Claim 10
Dependent Claim
22 words
A method as claimed in claIm 1 wherein the pressure of the plasma is in the range of 0.1 to 10 millibars.
Claim 11
Dependent Claim
43 words
A method as claimed in claim 1 in which a mixture is separated into its components by gas chromatography to provide a gas stream as an effluent, the effluent therefrom is passed into the plasma and one or more individual components are analysed.
Claim 12
Dependent Claim
38 words
A method as claimed in claim 8 in which the component to be analyzed is present in a much small concentration than another component and the plasma is by-passed when said other component would otherwise pass into it.
Claim 13
Dependent Claim
18 words
A method as claimed in claim 8 in which oxygen is determined, the scavenger for carbon being nitrogen.
Claim 14
Dependent Claim
18 words
A method as claimed in claim 8 in which nitrogen is determined, the scavenger for carbon being oxygen.
Claim 15
Dependent Claim
21 words
A method as claimed in claim 8 in which oxygen and nitrogen are determined and in which the scavenger is hydrogen.
Claim 16
Dependent Claim
30 words
The method of claim 1 wherein the carbon-containing sample contains oxygen, the scavenger for carbon is nitrogen and the quantities of carbon and oxygen present in the sample are determined.
Claim 17
Dependent Claim
31 words
The method of claim 1 in which the carbon-containing sample contains nitrogen, the scavenger for carbon is oxygen and the quantities of carbon and nitrogen present in the sample are determined.
Claim 18
Dependent Claim
58 words
Apparatus for determining the empirical formula of an organic compound which comprises means for dissociating the compound in the gas phase in a plasma in the presence of a scavenger for carbon, means for resolving radiation emitted by the plasma according to its frequency and means for detecting the intensity of radiation of frequencies characteristic of individual elements.
Claim 19
Dependent Claim
58 words
Apparatus for determining the empirical formula of an organic compound which comprises means for dissociating the compound in the gas phase in a plasma in the presence of a scavenger for carbon, means for resolving radiation emitted by the plasma according to its frequency and means for detecting the intensity of radiation of frequencies characteristic of individual elements.
Claim 20
Dependent Claim
45 words
Apparatus as claimed in claim 15 in which the means for resolving the radiation emitted by the plasma according to its frequency and means for detecting the intensity of radiation of frequencies characteristic of one or more individual elements is a multichannel diffraction grating spectrometer.
Claim 21
Dependent Claim
36 words
Apparatus as claimed in claim 15 which comprises a gas chromatographic system which passes its effluent to the plasma, the system being provided with means for introducing a scavenger for carbon before the compound is dissociated.
Claim 22
Independent Claim
86 words
A method of determining the elemental analysis of components present in a mixture in which the components are separated by gas chromatography to a stream of helium, passed into a plasma in the presence of a carbon lay-down suppressing amount of a scavenger for carbon, resolving radiation emitted by the plasma according to its frequency, detecting the intensity of radiation characteristic of the elements present in the component and determining the quantity of the elements present in the component from the intensity of radiation so detected.
Claim 23
Independent Claim
86 words
A method of determining the elemental analysis of components present in a mixture in which the components are separated by gas chromatography to a stream of helium, passed into a plasma in the presence of a carbon lay-down suppressing amount of a scavenger for carbon, resolving radiation emitted by the plasma according to its frequency, detecting the intensity of radiation characteristic of the elements present in the component and determining the quantity of the elements present in the component from the intensity of radiation so detected.
Claim 24
Dependent Claim
65 words
Apparatus for determining an elemental analysis of a carbon-containing sample which comprises means for introducing a scavenger for carbon, additional means for introducing the sample to a plasma in the presence of the scavenger for carbon, means for resolving radiation emitted by the plasma according to its frequency and means for detecting the intensity of radiation of frequencies characteristic of one or more individual elements.
Claim 25
Dependent Claim
65 words
Apparatus for determining an elemental analysis of a carbon-containing sample which comprises means for introducing a scavenger for carbon, additional means for introducing the sample to a plasma in the presence of the scavenger for carbon, means for resolving radiation emitted by the plasma according to its frequency and means for detecting the intensity of radiation of frequencies characteristic of one or more individual elements.
References Cited (Backward Citations)
US3467471A
Cited
US3610759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |