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US4529879A
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Process for the determination of isotopes by mass spectrometry
Assignee: Université de Sherbrooke
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Filing: 1983-04-15
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Granted: 1985-07-16
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Expires: 2003-04-15
Abstract
Abstract The invention relates to a mass spectrometry method for determining the absolute value of a given isotopic ratio of an unknown sample and/or the difference of isotope content between an unknown sample and a reference, which comprises (a) obtaining with or without chemical reaction a substrate capable of providing a fragmentation characteristic of the presence or absence of a specified isotope and usable to retrace the parent ions by the metastable ions technique consisting of accelerating voltage scan, (b) introducing said substrate into the source of a mass spectrometer followed by the ionization of said substrate, (c) retracing with metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of the specified isotope in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the metastable transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Inventors
- 👤 Jean P. Schmit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:39
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
167 words
A mass spectrometry method for determining the absolute value of a given isotopic ratio of an unknown sample and/or the difference of isotope content between an unknown sample and a reference, which comprises (a) obtaining a substrate capable of providing a fragmentation characteristic of the presence or absence of a specified isotope and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating scan, (b) introducing said substrate into the source of a mass spectrometer followed by the ionization of said substrate, (c) retracing with metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of the specified isotope in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 2
Dependent Claim
167 words
A mass spectrometry method for determining the absolute value of a given isotopic ratio of an unknown sample and/or the difference of isotope content between an unknown sample and a reference, which comprises (a) obtaining a substrate capable of providing a fragmentation characteristic of the presence or absence of a specified isotope and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating scan, (b) introducing said substrate into the source of a mass spectrometer followed by the ionization of said substrate, (c) retracing with metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of the specified isotope in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 3
Dependent Claim
201 words
A mass spectrometry method for determining the absolute value of deuterium content of an unknown aqueous sample and/or the difference of deuterium content between an unknown aqueous sample and a reference, which comprises (a) mixing a given volume of an aqueous sample with a substrate capable of interchanging hydrogen and deuterium in an aqueous medium, and capable of providing a fragmentation characteristic of the presence or absence of a specific deuterium and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracing with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of a specific deuterium in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus one mass unit, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 4
Dependent Claim
201 words
A mass spectrometry method for determining the absolute value of deuterium content of an unknown aqueous sample and/or the difference of deuterium content between an unknown aqueous sample and a reference, which comprises (a) mixing a given volume of an aqueous sample with a substrate capable of interchanging hydrogen and deuterium in an aqueous medium, and capable of providing a fragmentation characteristic of the presence or absence of a specific deuterium and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracing with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of a specific deuterium in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus one mass unit, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 5
Dependent Claim
13 words
A method according to claim 1 or 2, wherein the substrate is 1-propanol.
Claim 6
Dependent Claim
202 words
A mass spectrometry method for determining the absolute value of oxygen-18 content of an unknown aqueous sample and/or the difference of oxygen-18 content between an unknown aqueous sample and a reference, which comprises (a) introducing oxygen-18 from water samples into the carbonyl group of ethyl propanoate by hydrolysis of its triethyl ortho propionate ester derivative, and capable of providing a fragmentation characteristic of the presence or absence of a specific oxygen-18 and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracting with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or the absence of a specific oxygen-18 in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus two mass units, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 7
Dependent Claim
202 words
A mass spectrometry method for determining the absolute value of oxygen-18 content of an unknown aqueous sample and/or the difference of oxygen-18 content between an unknown aqueous sample and a reference, which comprises (a) introducing oxygen-18 from water samples into the carbonyl group of ethyl propanoate by hydrolysis of its triethyl ortho propionate ester derivative, and capable of providing a fragmentation characteristic of the presence or absence of a specific oxygen-18 and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracting with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or the absence of a specific oxygen-18 in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first, said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus two mass units, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 8
Dependent Claim
12 words
A method according to claim 1 wherein the substrate is ethyl propanoate.
Claim 9
Dependent Claim
11 words
A method according to claim 2 wherein the substrate is 1-propanol.
Claim 10
Dependent Claim
12 words
A method according to claim 4 wherein the substrate is ethyl propionate.
Claim 11
Dependent Claim
203 words
A mass spectrometry method for determining the absolute value of deuterium content of an unknown aqueous sample and/or the difference of deuterium content between an unknown aqueous sample and a reference, which comprises (a) mixing a given volume of an aqueous sample with a substrate capable of trapping hydrogen and deuterium from water samples by chemical reaction and capable of providing a fragmentation characteristic of the presence or absence of a specific deuterium and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracing with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of a specific deuterium in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus one mass unit, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 12
Dependent Claim
203 words
A mass spectrometry method for determining the absolute value of deuterium content of an unknown aqueous sample and/or the difference of deuterium content between an unknown aqueous sample and a reference, which comprises (a) mixing a given volume of an aqueous sample with a substrate capable of trapping hydrogen and deuterium from water samples by chemical reaction and capable of providing a fragmentation characteristic of the presence or absence of a specific deuterium and usable to retrace the parent ions by the metastable ions technique consisting of the accelerating voltage scan, (b) introducing said mixture into the source of a mass spectrometer followed by the ionization of said mixture, (c) retracing with the metastable ions technique the parent ions of a daughter ion resulting from the loss of a neutral fragment characteristic of the presence or absence of a specific deuterium in the substrate, (d) comparing the relative intensities, as expressed by peak areas or heights, of the transitions between, first said daughter ion and the substrate parent ion, and second, said daughter ion and the substrate parent ion plus one mass unit, or the latter transition and a transition characteristic of another isotope of well known abundance and usable as internal reference.
Claim 13
Dependent Claim
11 words
A method according to claim 8 wherein the substrate is 1-propanol.
References Cited (Backward Citations)
US3579270A
Cited
US3493743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-15 | 1989-01-14 | 1989-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-15 | 1993-01-14 | 1993-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-15 | 1997-01-14 | 1997-07-16 | $7700.00 | Window Closed / Lapsed |