Time-compressed chromatography in mass spectrometry

• US 5,175,430 A
• Filed: 05/17/1991
• Issued: 12/29/1992
• Est. Priority Date: 05/17/1991
• Status: Expired due to Term

• Current Assignee: LECO Corporation, The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: Meridian Instruments, Inc.
• Inventors: Yefchak, George E., McLane, Richard D., Enke, Christie G., Holland, John F.
• Primary Examiner(s): Anderson, Bruce C.
• Application Number:
  US07/702,221
• Time in Patent Office: 592 Days
• Field of Search: 250/288, 250/281, 250/282
• US Class Current: 250/282
• CPC Class Codes: G01N 30/7206 interfaced to gas chromatograph interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04
• CPC Class Codes: G01N 30/8624 Detection of slopes or peaks; baseline correction
• CPC Class Codes: G01N 30/8631 Peaks
• CPC Class Codes: G01N 30/8679 Target compound analysis, i.e. whereby a limited number of peaks is analysed

Abstract

A process and apparatus employing the time compression of chromatography in mass spectrometry with array detection in which the time compressed informatioin is deconvoluted by mathematical analysis for recovery of analytical information made inaccessible in the time compression and thereby resulting in a decrease in analysis time and improved component identification without loss of sensitivity.

Claims

1. A method for reducing the time required in chromatographic analyses comprising the following:

compression in time of a chromatographic separation of analytes on a chromatographic column resulting in a loss of chromatographic resolution;

transport of the column eluent into a mass spectrometer ion source;

generation of ions within the ion source;

mass analysis by rapid array detection mass spectrometry;

acquisition and computer processing of said mass spectral information including mathematical deconvolution of overlapping chromatographic peaks; and

said deconvolution constituting recovery of all of the chromatographic analytical information.

2. In the method of claim 1 wherein mass analysis by rapid array detection is accomplished by a time-of-flight mass spectrometer employing time array detection by use of an integrating transient recorder.

3. A method as claimed in claim 2 in which mass spectra are generated at a rate commensurate with the temporal information contained in the eluting chromatographic peaks and sufficient for deconvolution of overlapping peaks.

4. A method as claimed in claim 3 in which acquisition and integration of mass spectral information is selectively accomplished by digital summing of time-of-flight mass spectral transients and by analog integration of spectral region of interest followed by digital acquisition.

5. A method as claimed in claim 4 in which mass spectral data are processed via computerized deconvolution algorithms capable of recovering information made inaccessable by time-compression.

6. A device for time-compressed chromatography comprising:

a chromatograph having a column and a sample inlet system;

an interface for transporting the column eluent into a mass spectrometer ion source;

a mass analyzer capable of high speed array detection;

a data system for collection, processing, storage, and output of mass spectrometer data files;

said processing including the execution of algorithms appropriate for the mathematical deconvolution of overlapping chromatographic peaks;

means to compress said peaks in time whereby losses in resolution produced by said time compression are recovered by the mathematical deconvolution resident in and executed by said data system.

7. A device as in claim 6 wherein chromatographic separation of analytes is performed in a chromatograph such as a Hewlett-Packard 5890-A gas chromatograph and a time-of-flight spectrometer employing a time array detector by means of an integrating transient recorder.

8. A device as in claim 6 wherein a data system capable of sufficient data transfer rates and processing speed collects, processes, stores and outputs mass spectral data;

said processing including the execution of deconvolution algorithms appropriate for the mathematical deconvolution of overlapping chromatographic peaks.

9. A device as in claim 8 wherein ions are generated and stored in an ion source capable of synchronous extraction of ions for time-of-flight mass analysis.

10. A device as in claim 8 wherein ions are mass-analyzed by time-of-flight mass spectrometry;

said ions being temporally focused over the entire mass range of interest by use of an ion mirror or other means.

11. A device as in claim 10 wherein ion signals are measured by means of a detector, such as a multi-channel plate detector, capable of nanosecond-range time response and providing a large dynamic range.