Data processing system and method for chromatograph

Abstract

A data processing system for a chromatograph including a standard sample data storage section; a standard sample sensitivity factor calculator; a post-correction standard sample chromatogram strength calculator; a specific designated retention time and specific designated wavelength setter; a measurement sample data storage section; a measurement sample sensitivity factor calculator; and a post-correction measurement sample chromatogram creator.

Claims

1. A data processing system for a chromatograph for creating a chromatogram based on a temporal change of a spectrum obtained within a wavelength range including a target wavelength corresponding to a target component, the system comprising: a-1) a standard sample data storage section that is implemented by a memory and configured for storing a set of data of the spectrum for each of a plurality of standard samples having different concentrations of the target component; a-2) a standard sample sensitivity factor calculator that is implemented by a processor and configured for calculating, for each of the standard samples, a standard sample sensitivity factor by dividing a first strength which is an strength at the target wavelength of the spectrum of the standard sample at a designated retention time common to all of the standard samples, by a second strength which is an strength at a designated wavelength which is within the aforementioned wavelength range and yet different from the target wavelength; a-3) a post-correction standard sample chromatogram strength calculator that is implemented by the processor and configured for calculating, for each of the standard samples, a peak strength of a post-correction standard sample chromatogram obtained by multiplying a chromatogram at the designated wavelength by the standard sample sensitivity factor; a-4) an index value calculator that is implemented by the processor and configured for calculating an index value showing a degree of correlation between the concentration of the standard sample and the peak strength of the post-correction standard sample chromatogram; a-5) a specific designated retention time and specific designated wavelength setter that is implemented by the processor and configured for changing one or both of the designated retention time and the designated wavelength, for selecting a combination of the designated retention time and the designated wavelength at which the index value is within a predetermined range which indicates that the degree of correlation is high, as well as for setting the selected combination as a specific designated retention time and a specific designated wavelength; b-1) a measurement sample data storage section that is implemented by the memory and configured for storing spectrum data of a measurement sample having an unknown concentration of the target component; b-2) a measurement sample sensitivity factor calculator that is implemented by the processor and configured for calculating a measurement sample sensitivity factor by dividing a first strength which is an strength at the target wavelength of the spectrum of the measurement sample at the specific designated retention time by a second strength which is an strength of the same spectrum at the specific designated wavelength; b-3) a post-correction measurement sample chromatogram creator that is implemented by the processor and configured for creating a post-correction measurement sample chromatogram by multiplying a chromatogram at the specific designated wavelength by the measurement sample sensitivity factor; and a user interface configured for receiving user input to be used in the creating the post-correction measurement sample chromatogram and for displaying the created post-correction measurement sample chromatogram.

2. The data processing system for a chromatograph according to claim 1, comprising a calibration curve creator for creating a calibration curve based on the concentration of the standard sample at the specified designated retention time and the specific designated wavelength as well as on the peak strength of the post-correction standard sample chromatogram.

3. The data processing system for a chromatograph according to claim 2, wherein the index value is a correlation coefficient C given by: $C=\frac{\underset{i=1}{\overset{n}{.Math.}}\left(d_i-d_{\mathrm{av}}\right)\left(I_i-I_{\mathrm{av}}\right)}{\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(d_i-d_{\mathrm{av}}\right)}^2}\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(I_i-I_{\mathrm{av}}\right)}^2}}$ where data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) are a series of data obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, d.sub.av is an average value of the concentration d.sub.i, and I.sub.av is an average value of the peak strength I.sub.i.

4. The data processing system for a chromatograph according to claim 3, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

5. The data processing system for a chromatograph according to claim 2, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

6. The data processing system for a chromatograph according to claim 1, wherein the index value is a correlation coefficient C given by: $C=\frac{\underset{i=1}{\overset{n}{.Math.}}\left(d_i-d_{\mathrm{av}}\right)\left(I_i-I_{\mathrm{av}}\right)}{\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(d_i-d_{\mathrm{av}}\right)}^2}\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(I_i-I_{\mathrm{av}}\right)}^2}}$ where data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) are a series of data obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, d.sub.av is an average value of the concentration d.sub.i, and I.sub.av is an average value of the peak strength I.sub.i.

7. The data processing system for a chromatograph according to claim 6, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

8. The data processing system for a chromatograph according to claim 1, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

9. A data processing system for a chromatograph for specifying a parameter used in a process of creating a chromatogram based on a temporal change of a spectrum obtained within a wavelength range including a target wavelength corresponding to a target component, the system comprising: 1) a standard sample data storage section that is implemented by a memory and configured for storing a set of data of the spectrum for each of a plurality of standard samples having different concentrations of the target component; 2) a standard sample sensitivity factor calculator that is implemented by a processor and configured for calculating, for each of the standard samples, a standard sample sensitivity factor by dividing a first strength which is an strength at the target wavelength of the spectrum of the standard sample at a designated retention time common to all of the standard samples, by a second strength which is an strength at a designated wavelength which is within the aforementioned wavelength range and yet different from the target wavelength; 3) a post-correction standard sample chromatogram strength calculator that is implemented by the processor and configured for calculating, for each of the standard samples, a peak strength of a post-correction standard sample chromatogram obtained by multiplying a chromatogram at the designated wavelength by the standard sample sensitivity factor; 4) an index value calculator that is implemented by the processor and configured for calculating an index value showing a degree of correlation between the concentration of the standard sample and the peak strength of the post-correction standard sample chromatogram; 5) a specific designated retention time and specific designated wavelength setter that is implemented by the processor and configured for changing one or both of the designated retention time and the designated wavelength, for selecting a combination of the designated retention time and the designated wavelength at which the index value is within a predetermined range which indicates that the degree of correlation is high, as well as for setting the selected combination as a specific designated retention time and a specific designated wavelength; and a user interface configured for receiving user input to be used in creating a post-correction measurement sample chromatogram based on the specific designated retention time and the specific designated wavelength, and for displaying the created post-correction measurement sample chromatogram.

10. The data processing system for a chromatograph according to claim 9, comprising a calibration curve creator for creating a calibration curve based on the concentration of the standard sample at the specified designated retention time and the specific designated wavelength as well as on the peak strength of the post-correction standard sample chromatogram.

11. The data processing system for a chromatograph according to claim 10, wherein the index value is a correlation coefficient C given by: $C=\frac{\underset{i=1}{\overset{n}{.Math.}}\left(d_i-d_{\mathrm{av}}\right)\left(I_i-I_{\mathrm{av}}\right)}{\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(d_i-d_{\mathrm{av}}\right)}^2}\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(I_i-I_{\mathrm{av}}\right)}^2}}$ where data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) are a series of data obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, d.sub.av is an average value of the concentration d.sub.i, and I.sub.av is an average value of the peak strength I.sub.i.

12. The data processing system for a chromatograph according to claim 11, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

13. The data processing system for a chromatograph according to claim 10, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

14. The data processing system for a chromatograph according to claim 9, wherein the index value is a correlation coefficient C given by: $C=\frac{\underset{i=1}{\overset{n}{.Math.}}\left(d_i-d_{\mathrm{av}}\right)\left(I_i-I_{\mathrm{av}}\right)}{\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(d_i-d_{\mathrm{av}}\right)}^2}\sqrt{\underset{i=1}{\overset{n}{.Math.}}{\left(I_i-I_{\mathrm{av}}\right)}^2}}$ where data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) are a series of data obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, d.sub.av is an average value of the concentration d.sub.i, and I.sub.av is an average value of the peak strength I.sub.i.

15. The data processing system for a chromatograph according to claim 14, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

16. The data processing system for a chromatograph according to claim 9, wherein, for a linear function I=kd of concentration d and peak strength I (where k is a coefficient) determined based on a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) obtained for n kinds of standards samples having different concentrations of the target component (where n is a natural number equal to or greater than two) with d.sub.i denoting the concentration and I.sub.i denoting the peak strength of the post-correction standard sample chromatogram, the index value is an average value or largest value of an absolute value of a deviation which is a difference between a value kd.sub.i of the linear function and the measured value I.sub.i of each standard sample.

17. A data processing method for a chromatograph for creating a chromatogram based on a temporal change of a spectrum obtained within a wavelength range including a target wavelength corresponding to a target component, the method comprising the steps of: calculating, for each of a plurality of standard samples having different concentrations of the target component, a standard sample sensitivity factor by dividing a first strength which is an strength at the target wavelength of the spectrum of the standard sample at a designated retention time common to all of the standard samples by a second strength which is an strength at a designated wavelength which is within the aforementioned wavelength range and yet different from the target wavelength; calculating, for each of the standard samples, a peak strength of a post-correction standard sample chromatogram obtained by multiplying a chromatogram at the designated wavelength by the standard sample sensitivity factor; calculating an index value showing a degree of correlation between the concentration of the standard sample and the peak strength of the post-correction standard sample chromatogram; setting a specific designated retention time and a specific designated wavelength by changing one or both of the designated retention time and the designated wavelength, and by selecting a combination of the designated retention time and the designated wavelength at which the index value is within a predetermined range which indicates that the degree of correlation is high; calculating, for a measurement sample having an unknown concentration of the target component, a measurement sample sensitivity factor by dividing a first strength which is an strength at the target wavelength of the spectrum of the measurement sample at the specific designated retention time by a second strength which is an strength of the same spectrum at the specific designated wavelength; creating a post-correction measurement sample chromatogram by multiplying a chromatogram at the specific designated wavelength by the measurement sample sensitivity factor; and displaying, on a user interface, the created post-correction measurement sample chromatogram, wherein the user interface is configured to receive user input to be used in the creating the post-correction measurement sample chromatogram.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic configuration diagram of an analyzing system including one embodiment of the data processing system for a chromatograph according to the present invention.

(2) FIG. 2 shows one example of the quantitative determination browser window used for the parameter setting.

(3) FIG. 3 shows one example of the parameter search condition input window used for the parameter setting.

(4) FIG. 4 shows one example of the data analyzing window used for creating a chromatogram of a measurement sample.

(5) FIGS. 5A, 5B, 5C, and 5D illustrate a method used in the data processing system for a chromatograph of the present embodiment, for removing noise components of detection signals in the data for creating a chromatogram.

(6) FIG. 6 is a flowchart for explaining an operation of the parameter setter in the data processing system for a chromatograph of the present embodiment.

(7) FIG. 7A is a calibration curve in the case where the chromatogram is not corrected, and FIG. 7B is a calibration curve obtained after the chromatogram is corrected by the method of the present embodiment.

(8) FIG. 8 is a flowchart for explaining an operation of the measurement sample chromatogram creator in the data processing system for a chromatograph of the present embodiment.

(9) FIG. 9 a schematic configuration diagram showing another embodiment of the data processing system for a chromatograph according to the present invention.

DESCRIPTION OF EMBODIMENTS

(10) One embodiment of the data processing system for a chromatograph according to the present invention is described using FIGS. 1-9. The following description deals with the case of a liquid chromatograph (LC). It should be noted that the description similarly applies in the case of a gas chromatograph.

Embodiment

(11) (1) Configuration of Data Processing System for Chromatograph of Present Embodiment

(12) The data processing system for a chromatograph of the present embodiment constitutes a portion of the analyzing system shown in FIG. 1. The analyzing system 10 has an LC 11 for temporally separating the components contained in a liquid sample, a detector 12 for analyzing each of the separated components within a predetermined wavelength band, and a data processing system 13 for a chromatogram (the system of the present embodiment, which is hereinafter called the data processing system) for processing data produced by the detector 12.

(13) The data processing system 13 consists of a computer (hardware) and a dedicated data-processing software program installed on the same computer, where the computer is a commonly used computer having a CPU (central processing unit), storage device (a memory unit, hard disk, solid-state drive and/or other devices), display unit, input device (a keyboard, mouse and other devices) and other components. The data processing system 13 functions as a parameter setting section 131 and a measurement sample chromatogram creating section 132.

(14) The parameter setting section 131 is provided for setting the aforementioned specific designated retention time and specific designated wavelength using the result of a measurement of a plurality of standard samples which respectively contain a target component at known and mutually different concentrations. This section has a parameter search condition input section 1310 for allowing users to input various conditions (which will be described later) for the setting, and a standard sample data storage section 1311 for storing measurement data of spectra at a large number of retention times for each of a plurality of different kinds of standard samples having different concentrations. The parameter setting section 131 also has a standard sample sensitivity factor calculator 1312, post-correction standard sample chromatogram strength calculator 1313, index value calculator 1314, specific designated retention time and specific designated wavelength setter 1315, and calibration curve creator 1316. These components will be explained when the operation of the data processing system 13 is described.

(15) The measurement sample chromatogram creating section 132 has a measurement sample data storage section 1321, measurement sample sensitivity factor calculator 1322, and post-correction measurement sample chromatogram creator 1323, for performing a process using the result of a measurement performed on a measurement sample having an unknown concentration of the target component as well as the specific designated retention time and the specific designated wavelength, so as to eventually create a post-correction chromatogram of the measurement sample. The measurement sample data storage section 1321 is provided for storing measurement data of spectra at a large number of retention times for each measurement sample. The functions of the measurement sample sensitivity factor calculator 1322 and the post-correction measurement sample chromatogram creator 1323 will be described when the operation of the data processing system 13 is described.

(16) On the display unit of the data processing system 13, two windows are displayed: the quantitative determination browser window 20 as shown in FIG. 2 and the data analyzing window 40 as shown in FIG. 4. When a user performs a predetermined operation on the quantitative determination browser window 20, such as clicking a specific icon or selecting a specific item from the Window (W) pulldown menu, the parameter search condition input window 30 as shown in FIG. 3 is displayed. Hereinafter, the quantitative determination browser window 20, parameter search condition input window 30 and data analyzing window 40 are sequentially described.

(17) The quantitative determination browser window 20 is a window to be used for the parameter setting using standard samples. It has a quantitative determination result view 21, chromatogram view 22, calibration curve/spectrum view 23, and other display areas. The quantitative result view 21 shows various items of information for each of a plurality of standard samples having known concentrations of the target component, such as the name of the data file, the area and height calculated from a chromatogram (the numerical values of the area and height can be changed by the data processing performed by the data processing system 13, which will be described later), as well as the concentration. The chromatogram view 22 shows a chromatogram of one kind of standard sample selected on the quantitative determination result view 21 by a user using a mouse or similar device. The tabs shown in the chromatogram view 22 allow the operation of switching the display to the detailed sample information stored in the data file related to the one kind of standard sample. The calibration curve/spectrum view 23 also has tabs for selectively displaying either a calibration curve or a spectrum of one standard sample at one retention time. The calibration curve is a graph showing the relationship between the concentration of the standard sample and the strength (area or height) of the chromatogram. This graph is used for determining the concentration of a measurement sample having an unknown concentration from the strength of a chromatogram of the measurement sample. The calibration curve can be changed by the data processing performed by the data processing system 13 (which will be described later).

(18) The parameter search condition input window 30 is a window for allowing users to input the conditions for the parameter setting using the standard samples and execute an automatic search of the parameters.

(19) Displayed in the upper portion of the parameter search condition input window 30 are the input fields of the Correction Wavelength Setting Method, Correction Wavelength (Manual), Correction Wavelength (Auto) Strength, Correction Wavelength (Auto) Movement Direction, Strength for Extracting the Sensitivity Correction Spectrum and Background Correction. In the Correction Wavelength Setting Method input field, the radio buttons for allowing users to select whether the aforementioned specific designated wavelength should be set automatically or manually are displayed. When Auto is selected, the data processing system 13 functions as one embodiment of the present invention. The Correction Wavelength (Manual) input field is a field which is enabled to allow users to input a numerical value of the specific designated wavelength when Manual is selected in the Correction Wavelength Setting Method input field. This case is unrelated to the embodiment of the present invention, and therefore, will not be described in detail. Detailed descriptions of the Correction Wavelength (Auto) Strength input field, Correction Wavelength (Auto) Movement Direction input field, Strength for Extracting the Sensitivity Correction Spectrum input field, and Background Correction input field will be made when the operation of the data processing system 13 is described.

(20) In the lower portion of the parameter search condition input window 30, a field for selecting the calculation method for determining the index value showing the degree of correlation between the concentration of the standard sample and the aforementioned strength of the post-correction standard sample chromatogram is displayed. In the present embodiment, one or more indices can be selected from three kinds of indices: the correlation coefficient of the calibration curve, the average of the deviation, and the largest value of the deviation. Additionally, a set of buttons are displayed in the parameter search condition input window 30, including the Begin Search button for commanding the system to initiate the automatic parameter search after the input of the aforementioned conditions is completed.

(21) The data analyzing window 40 is a window used for processing the data of the measurement sample. It has the contour view 41, spectrum view 42, chromatogram view 43, and other display areas. The contour view 41 shows the signal strength of the detector 12 by contour lines on a graph with the horizontal axis indicating the retention time and the vertical axis indicating the wavelength of the light detected with the detector 12. The spectrum view 42 shows the spectrum of the measurement sample at a specific retention time. The chromatogram view 43 shows a post-correction chromatogram of the measurement sample.

(22) (2) Method for Correcting Saturation and Deformation of Chromatogram

(23) Before the operation of the data processing system for a chromatograph according to the present embodiment is described, the method used in the system in order to correct saturation and deformation which can occur in a chromatogram is described using FIGS. 5A, 5B, 5C, 5D. This correction method is applied to both of the standard sample data and measurement sample data.

(24) In general, if the concentration of the target component in the sample is too high, the pre-correction chromatogram 511 becomes saturated or deformed at a retention time T.sub.0 included in a certain range, as shown in FIG. 5A. Such a saturation of the pre-correction chromatogram 511 occurs due to the saturation of the spectrum 521 at the retention time T.sub.0 (which is hereinafter called the first spectrum), as shown in FIG. 5B. Since all spectra of one target component have a specific shape to that component, if neither the saturation nor deformation occurs, these spectra become similar to each other in shape and merely differ from each other in their strengths. By using this similarity, the saturation or deformation of the pre-correction chromatogram 511 is corrected as follows:

(25) Initially, one retention time T.sub.s at which the pre-correction chromatogram 511 is not saturated is designated (FIG. 5A). This retention time T.sub.s is called the designated retention time. The designated retention time T.sub.s may be directly designated. However, it is also possible to select an strength I.sub.s1 on the pre-correction chromatogram 511 and thereby designate the point in time corresponding to that strength as the designated retention time, since it is when the strength is equal to or lower than a predetermined level that the pre-correction chromatogram 511 does not saturate. The value entered in the aforementioned Strength for Extracting the Sensitivity Correction Spectrum input field in the parameter search condition input window 30 corresponds to the strength I.sub.s1 selected for this purpose. The spectrum 522 at this designated retention time T.sub.s (which is hereinafter called the second spectrum) is neither saturated nor deformed (FIG. 5B).

(26) Subsequently, a wavelength .sub.s at which the first spectrum 521 is neither saturated nor deformed is specified (FIG. 5B). This wavelength .sub.s is called the designated wavelength. Once again, instead of directly specifying the designated wavelength .sub.s, it is possible to select an strength I.sub.s2 equal to or lower than a predetermined level at which no saturation of the spectrum occurs and thereby designate the wavelength corresponding to that strength as the designated wavelength .sub.s. The value entered in the aforementioned Correction Wavelength (Auto) Strength input field in the parameter search condition input window 30 corresponds to the strength .sub.s2 selected for this purpose.

(27) After that, the first strength I.sub.a, which is the strength of the second spectrum 522 at the target wavelength .sub.t at which the spectrum of the target compound is maximized (normally, if the kind of target component is known, this wavelength is also known), and the second strength I.sub.b, which is the strength of the second spectrum 522 at the designated wavelength .sub.s, are determined (FIG. 5C). Then, the sensitivity factor, i.e. the ratio of the first strength I.sub.a to the second strength b, is calculated by K=I.sub.a/I.sub.b.

(28) Due to the previously described similarity of the spectra, the ratio of the first strength I.sub.a to the second strength I.sub.b on the second spectrum 522 is equal to the ratio of the strength of the first spectrum 521 at the target wavelength .sub.t to the strength of the same spectrum at the designated wavelength .sub.s. Accordingly, by creating a chromatogram 531 at the designated wavelength .sub.s at which the first spectrum 521 is neither saturated nor deformed, and then multiplying the chromatogram 531 by the sensitivity factor K, a post-correction chromatogram 532 which is neither saturated nor deformed at the target wavelength .sub.t can be obtained.

(29) (3) Operation of Data Processing System for Chromatograph of Present Embodiment

(30) An operation of the data processing system 13 is hereinafter described using the flowcharts of FIGS. 6 and 8 as well as the drawing of the calibration curve of FIG. 7.

(31) (3-1) Operation of Parameter Setting Section 131

(32) Initially, when the user performs the aforementioned predetermined operation on the quantitative determination browser window 20, the parameter search condition input section 1310 displays the parameter search condition input window 30 on the display unit (Step S1) and stands by until the user presses the Begin Search button after completing the input of the various conditions (Step S2).

(33) On the parameter search condition input window 30, the user selects Auto in the Correction Wavelength Setting Method input field as well as inputs the setting values of the previously described strength I.sub.s1 for extracting the sensitivity correction spectrum and the correction wavelength (auto) strength I.sub.s2 into the Strength for Extracting the Sensitivity Correction Spectrum and Correction Wavelength (Auto) Strength input fields, respectively. It should be noted that these values are merely set as initial values; the optimum values are eventually determined by the data processing system 13 of the present embodiment. The user also inputs, into the Strength for Extracting the Sensitivity Correction Spectrum and Correction Wavelength (Auto) Strength input fields, numerical values which define the search range within which the strength I.sub.s1 for extracting the sensitivity correction spectrum and the correction wavelength (auto) strength I.sub.s2 are varied in the calculation of the optimum values by the data processing system 13, as well as a numerical value which defines the search step (interval) to vary those strength values. Additionally, the user inputs, into the Background Correction input field, whether or not the background correction is to be performed. The background correction is commonly performed in the data processing of chromatograms, and therefore, will not be described in the present embodiment. Furthermore, in the lower portion of the parameter search condition input window 30, the user selects the calculation method for determining the index value showing the degree of correlation between the concentration of the standard sample and the aforementioned strength of the post-correction standard sample chromatogram.

(34) In some cases, the wavelength corresponding to the correction wavelength (auto) strength I.sub.s2 is present on each of the longer and shorter wavelength sides of the target wavelength .sub.t. To deal with such a case, the user specifies, in the Correction Wavelength (Auto) Movement Direction input field, which side of the wavelength should be selected. It is possible to input one designated retention time T.sub.s instead of the strength I.sub.s1 for extracting the sensitivity correction spectrum. Similarly, it is possible to input one designated wavelength .sub.s instead of the correction wavelength (auto) strength I.sub.s2.

(35) After the input of these values has been completed, the user presses the Begin Search button, whereupon the process goes to Step S3. In Step S3, the standard sample sensitivity factor calculator 1312 retrieves spectrum data for each of a plurality of kinds of standard samples from the standard sample data storage section 1311. Next, for each standard sample, the standard sample sensitivity factor calculator 1312 calculates the sensitivity factor K described in (2), using one combination of the designated retention time T.sub.s and designated wavelength .sub.s (Step S4). Subsequently, for each standard sample, the post-correction standard sample chromatogram strength calculator 1313 creates the post-correction chromatogram 532 as described in (2) based on the sensitivity factor K obtained in Step S4, and calculates the peak strength (either the area strength of the peak or the peak-top strength) of the post-correction chromatogram 532 (Step S5).

(36) By the operations described thus far, a series of data {(d.sub.i, I.sub.i)} (i=1, 2, . . . , n) with d.sub.i denoting the concentrations of n kinds of standard samples and I.sub.i denoting the peak strengths of the post-correction chromatograms 532 of those standard samples are obtained for one combination of the designated retention time T.sub.s and designated wavelength .sub.s. Accordingly, the index value calculator 1314 calculates the index value at this combination of the designated retention time T.sub.s and designated wavelength .sub.s (Step S6). In the present embodiment, the index value selected by the user in the parameter search condition input window 30 is calculated, i.e. the correlation coefficient of the calibration curve, the average of the deviation, or the largest value of the deviation. Among these indices, the correlation coefficient of the calibration curve is calculated by the previously described calculation formula of the correlation coefficient C. The average or largest value of the deviation is calculated by determining the deviations by a commonly known method and taking an average or largest value of those deviations. In the case of the correlation coefficient C, a larger value means a higher degree of correlation. In the case of the average or largest value of the deviation, a smaller value means a higher degree of correlation.

(37) After the index value for one combination of the designated retention time T.sub.s and designated wavelength .sub.s has been calculated, the index value calculator 1314 checks whether or not the calculation of the index value has been completed for all combinations of the designated retention time T.sub.s and designated wavelength .sub.s corresponding to the search range and search step entered by the user in the parameter search condition input window 30 (Step S7). If the calculation is completed, the process goes to Step S9. If the calculation is not completed, the designated retention time T.sub.s and designated wavelength Xs are changed to a new combination for which the calculation of the index value has not been completed (Step S8), and the operations of Steps S4 through S6 are repeated.

(38) In Step S9, the specific designated retention time and specific designated wavelength setter 1315 selects, from among the plurality of combinations of the designated retention time T.sub.s and designated wavelength .sub.s obtained in the previously described process, the combination of the designated retention time T.sub.s and designated wavelength .sub.s at which the index value indicates the highest degree of correlation, as the specific designated retention time and specific designated wavelength. It is also possible to randomly select, from among the combinations of the designated retention time T.sub.s and designated wavelength .sub.s at which the index value has exceeded a predetermined reference level, one combination of the designated retention time T.sub.s and designated wavelength .sub.s as the specific designated retention time and specific designated wavelength. The strength values corresponding to the specific designated retention time and specific designated wavelength, as well as the calculated result of the correlation coefficient are displayed in the corresponding fields in the search condition input window 30.

(39) Subsequently, the calibration curve creator 1316 creates the calibration curve based on the series of data {(d.sub.i, I.sub.i)} obtained at the specific designated retention time and specific designated wavelength which have been determined. Before the correction of the chromatogram, the data points deviate from the straight line of the linear function due to the saturation of the chromatogram peak (FIG. 7A). By contrast, the calibration curve obtained in the present embodiment considerably agrees with the straight line of the linear function (FIG. 7B). The calibration curve creator 1316 displays the obtained post-correction calibration curve in the calibration curve/spectrum view 23 of the quantitative determination browser window 20.

(40) With this, the operation of the parameter setting section 131 is discontinued.

(41) (3-2) Operation of Measurement Sample Chromatogram Creating Section 132

(42) When the user performs a predetermined operation for specifying one measurement sample having an unknown concentration of the target component on the data analyzing window 40, the measurement sample chromatogram creating section 132 begins its operation. Initially, the measurement sample sensitivity factor calculator 1322 retrieves the spectrum data of the measurement sample from the measurement sample data storage section 1321 (Step S21). Next, the measurement sample sensitivity factor calculator 1322 computes the sensitivity factor K described in (2), using the specific designated retention time and specific designated wavelength selected by the parameter setting section 131 as T.sub.s and .sub.s, respectively (Step S22). Subsequently, the post-correction measurement sample chromatogram creator 1323 creates the post-correction chromatogram 532 of the measurement sample as described in (2) based on the sensitivity factor K obtained in Step S22 (Step S23). With this, the operation of the measurement chromatogram creating section 132 is discontinued.

(43) The present invention is not limited to the previous embodiment.

(44) For example, in the previous embodiment, the calibration curve creator 1316 in the parameter setting section 131 creates a calibration curve based on the data obtained at the specific designated retention time and specific designated wavelength. However, the calibration curve creator 1316 is dispensable if the purpose of the system is to merely select the specific designated retention time and specific designated wavelength. Conversely, if the purpose is to create the calibration curve without being affected by the saturation or deformation of the chromatogram, a configuration having the parameter setting section 131 without including the measurement sample chromatogram creating section 132 may be adopted, as in the case of the analyzing system 10A shown in FIG. 9.

REFERENCE SIGNS LIST

(45) 10, 10A . . . Analyzing System 11 . . . LC 12 . . . Detector 13 . . . Data Processing System 131 . . . Parameter Setting Section 1310 . . . Parameter Search Condition Input Section 1311 . . . Standard Sample Data Storage Section 1312 . . . Standard Sample Sensitivity Factor Calculator 1313 . . . Post-Correction Standard Sample Chromatogram Strength Calculator 1314 . . . Index Value Calculator 1315 . . . Specific Designated Retention Time and Specific Designated Wavelength Setter 1316 . . . Calibration Curve Creator 132 . . . Measurement Sample Chromatogram Creating Section 1321 . . . Measurement Sample Data Storage Section 1322 . . . Measurement Sample Sensitivity Factor Calculator 1323 . . . Post-Correction Measurement Sample Chromatogram Creator 20 . . . Quantitative Determination Browser Window 21 . . . Quantitative Determination Result View 22 . . . Chromatogram View 23 . . . Calibration Curve/Spectrum View 30 . . . Parameter Search Condition Input Window 40 . . . Data Analyzing Window 41 . . . Contour View 42 . . . Spectrum View 43 . . . Chromatogram View 511 . . . Pre-Correction Chromatogram 521 . . . First Spectrum 522 . . . Second Spectrum 531 . . . Chromatogram at Designated Wavelength k 532 . . . Post-Correction Chromatogram