Measuring and testing – Gas analysis – Gas chromatography
Reexamination Certificate
1999-12-29
2002-01-22
Larkin, Daniel S. (Department: 2856)
Measuring and testing
Gas analysis
Gas chromatography
C073S023350
Reexamination Certificate
active
06339950
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention resides in a process for determining the number of components in peaks, bands, and signals of chromatograms, electrograms, and spectrograms of all types obtained for analysis and substance separation wherever energy-correlated measurement values as a function of an evolving parameter appear and again disappear.
Modern analysis and separation techniques for any type of material proceed more and more toward a full automatization of the procedure from the sampling up to providing the desired final results. In such a procedure, the process scheme is repeated identically independently of the type of analysis. This is true generally for the locating and the identification of the material, but also for the sequencing of proteins, nucleic acids, carbohydrates, lipids, etc.: Progressive attachment, distribution on the basis of individual travel behavior and desorption of substances on various carrier materials and the subsequent substrate detection by way of dispositives sensitive thereto and preferably having a spectroscopic nature.
Experience has shown that, in addition to the homogeneous detection peaks which are generated by a single pure component (=100% peak purity), in other signals the spectral contributions of two or several components are mixed together (=mix-peaks).
The main reasons herefor are:
Quasi-identity of the components to be separated, for example, families of effective substances occur in the natural material chemistry. The individual components differ only slightly from one another.
The use of an unadapted separation process, which permits several components to appear in the same detection zone.
Peak determination under less than optimal conditions for the detection.
The peak purity and, if applicable, the number of spectrally overlapping components could not be easily recognized and utilized so far apparatus-logistically. When such uncertainties occur, the reaction of the apparatus is delayed and the final results are doubtful.
Highly developed measuring and separating processes, which are optimized in any other way, are limited in their efficiency by this general uncertainty factor.
U.S. Pat. No. 5,596,135 A discloses a process, which is based on the extinction difference diagrams. With this process, it can be determined whether a peak in a chromatogram is caused by one or several components. If there is more than one component, the number of components cannot be clearly determined.
EP 0 486 030 A discloses a similar method, which is based, however, on extinction diagrams.
Furthermore, EP 0 294 121 A discloses a method, wherein the number of components of a mixture can be determined using a mathematically complicated main component analysis (on the basis of a matrix with the determination of individual values and vectors).
It is the object of the present invention to provide a simple method by which the number of components in a mixture can be clearly determined.
SUMMARY OF THE INVENTION
In a process for determining the number of components involved in the formation of peaks, bands, and signals which are obtained in spectrograms where energy-correlated measurement values, such as extinctions, increase and decrease as a function of an evolving parameter, such as time, four different measurement values with at least three evolving parameter values are determined, three differences are formed from the four energy-correlated measurement values on the basis of the same evolving parameter, two quotients are formed from the respective differences and the two quotients are plotted over one another in a diagram, whereby a point is obtained if one component is responsible, a straight line is formed if two components are responsible, and a curve is formed if more than two components are responsible for the formation of the peaks, bands, or signals.
The method permits a precise and rapid determination of the number of components in peaks, bands, and signals, which are obtained for the analysis and component separation in all kinds of spectrograms, where energy correlated measurement values increase decrease as a function of an evolving parameter. The plurality of measurement values are derived from a particular such parameter value and differently energy-correlated so as to form characteristic geometric figures, in which the original evolving parameter is not contained. The figures obtained are reduced, depending on their complexity, in steps, first to straight lines and then to points. In this way, the number of the components involved in the formation of the peaks and consequently the composition of the whole spectrogram and also of the component mixture to be examined and/or separated is obtained in a simple manner.
In a preferred embodiment of the invention, instead of the energy-correlated direct-measurement values, the differences thereof or quotients thereof or even the quotients of the differences are placed in relation to one another in a simple way or in multiple ways. It becomes progressively possible thereby to extract 2, 3, 4 or more individual components from the peak and to identify and separate them. Also, the areas in a particular parameter range surrounded by the respective energy measurement values may be placed in relation to each other as integrals, whereby geometric figures are provided from which the peak compositions and analysis results can be obtained. This additionally improves the signal
oise ratio with a corresponding gain in sensitivity of the respective technical method.
A variant of the process for determining the number of components of spectrograms, wherein the structures are energy-correlated measurement values, which appear and disappear as a function of an evolving parameter and which consequently change with the parameter comprises the following process steps:
a) determining at least two different function values of measurement values, wherein each measurement value is assigned to a different energy, based on the same parameters,
b) determining at least two additional function values with the same energy correlation as in step a) based on at least two additional different parameters so that, for each energy value, there are at least three function values with three different parameters,
c) interpreting the function values belonging to the various energies as a parameter representation of an at least two-dimensional curve, and
d) evaluating the curve on the basis of predetermined criteria. The measurement values may be extinction values and the parameter may be time.
It is known that the separation and analysis processes of component mixtures operate, in their decisive phase, on the basis of registering those detection peaks, which are the result of spectroscopic measurement data. This is true for example for the HPLC-, the liquid-, the gas, the thin layer-, the affinity-, the adsorption-, and ion exchange chromatography, as well as for electrophoretic processes, and for any analog separation procedure.
From a simple and efficient elimination of the above-characterized central problem, an important technical advance for all automated separation and analysis processes can be expected.
The problems described earlier are eliminated by the process according to the invention. The process is direct, simple, free of delays and significant. It operates with a minimum of evaluation needs and leads to clear results.
The solution for the problem is centered about the detection peak.
Following the original classic separation processes, the number of analytical and preparative component separation procedures by way of chromatography has constantly increased. Alone in Europe, 100,000 such apparatus are in operation in all research and other professional areas. It can be assumed that this trend continues. Most detection and measurement methods in operation register the spectroscopic data dependent on the retention time and/or a travel behavior. The chromatograms obtained in this way are then used for the identification and the quantitative determination of individual components. It has been of u
Bengsch Eberhard
Kettrup Antonius
Polster Jürgen
Bach Klaus J.
GSF Foschungszentrum für Umwelt und Gesundheit GmbH
Larkin Daniel S.
LandOfFree
Process for determining the number of components in peaks,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for determining the number of components in peaks,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for determining the number of components in peaks,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2861036