Method and apparatus for the determination of isotopic composition
US4916313A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1988 |
| Grant date | Apr 10, 1990 |
| Priority date | — |
| Expiry date | Aug 31, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides a method and apparatus for the mass spectrometric determination of the isotopic composition of an element comprised in a sample by gas chromatography-isotopic ratio mass spectrometry. As a sample elutes from the column of the gas chromatograph it enters a sample conversion means which converts the element to an analysis gas (a gas comprising the element in elemental form or in the form of a simple compound, e.g. nitrogen or carbon dioxide) which is admitted into the mass spectrometer only during a second time interval corresponding to the elution of the peak containing the sample from the column. One or more calibration samples of a reference gas are admitted into the spectrometer during first time intervals which do not overlap the second time interval, thereby minimizing the contribution of the analysis gas to the reference gas mass analysis, and vice versa. Various devices are provided to minimize disturbance to the flow of gas into the spectrometer during practice of the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.