Mass spectrometric mixture analysis
View Patent ↗The invention relates to a mass spectrometric mixture analysis to determine both simple mass spectra of the substances as well as more detailed information about structures and other characteristics of the substances. The invention consists in temporally separating the substance mixture in a separating device, splitting the eluating flow of substances into at least two partial flows and measuring the substances in the different partial flows by mass spectrometry. A direct measurement provides a series of spectra whose evaluation is used for optimal control of the time at which a spectrum of another, delayed partial flow is acquired and the type of this measurement procedure. The substances of the delayed partial flows or their ions can thereby be chemically or physically modified in a variety of ways in order to provide the molecular weight as well as more detailed information.
1. Method for mass spectrometrically analyzing substance mixtures, comprising the steps of:
(a) temporally separating the substances of the mixture in a separating device,
(b) splitting the flow of temporally separated substances into at least two partial flows,
(c) measuring directly a partial flow by a mass spectrometer to obtain a series of mass spectra, and
(d) measuring at least one further partial flow mass spectrometrically with a delay in time, the delayed measurements being controlled by an evaluation of the series of mass spectra which are measured directly.
2. Method according to claim 1 , wherein the delayed measurements are conducted on ions which have been modified by chemical or physical reactions of the basic substances or of their ions.
3. Method according to claim 2 , wherein the delayed measurements are conducted on fragmented ions, whereby daughter ion spectra or granddaughter ion spectra are acquired.
4. Method according to claim 1 , wherein the separating device operates with chromatography or electrophoresis or with a combination of both.
5. Method according to claim 1 , wherein the splitting of the substance flow is done before the ionization of the substances, and the delay occurs in a capillary delay loop.
6. Method according to claim 1 , wherein the splitting of the substance flow occurs after the ionization of the substances as a splitting of the ion currents, and the delay is produced by passing through at least one ion storage device.
7. Method according to claim 6 , wherein more than one ion storage device is used in the form of a bucket brigade ion storage devices.
8. Method according to claim 1 , wherein the temporal delay corresponds to roughly at least half of the profile width of a substance batch from the separating device.
9. Method according to claim 1 , wherein the direct and the delayed measurements are conducted in different mass analyzers.
10. Method according to claim 1 , wherein the direct and the delayed measurements are conducted in regular or irregular alternation in the same mass analyzer.