JPH11326304A - Data processing device for chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select a wavelength appropriately under predetermined conditions when a chromatogram of specific wavelength is cut out from a three-dimensional chromatogram and performing quantitative analysis. SOLUTION: A predetermined area X containing a time base and a wavelength base is instructed (S2), and a maximum point to an object component in the area X is instructed (S5). Then a two-dimensional chromatogram is cut out for every predetermined wavelength step in the area X (S7), any of a peak area ratio, height ratio, or resolution is computed according to determined conditions on the basis of the peak of the object component and its preceding and succeeding peaks in each chromatogram (S8). Then the wavelength that provides the best value among the values obtained in each chromatogram is determined as an optimum wavelength (S9). The wavelength is stored in a wavelength table, and the retention time of peak of the object component is stored in an identification table (S10). By this, it is possible to obtain optimum data for performing quantitative analysis on the object component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromatographic data processor, and more particularly, to a chromatographic data processor for processing data of a three-dimensional chromatogram having a wavelength axis in addition to a time axis and an intensity axis. Related to the device.

[0002]

2. Description of the Related Art In a liquid chromatograph, a mobile phase is allowed to flow through a column at a constant flow rate, a liquid sample is injected into the mobile phase, and each component is temporally separated while passing through the column. The sample solution eluted from the column is detected by a detector. When a photodiode array detector (hereinafter referred to as a “PDA detector”) or the like is used as a detector, a plurality of data are simultaneously obtained by dispersing a relative intensity signal corresponding to a sample component eluted from a column outlet in a wavelength direction. can do.

That is, in this chromatographic apparatus,
Data having three dimensions of time t, relative intensity S, and wavelength λ is obtained, and FIG.
A three-dimensional chromatogram as shown in FIG. Generally, in such a three-dimensional chromatogram, the wavelength λ at which the maximum intensity appears differs for each sample component. Therefore,
When performing a quantitative analysis of a target component on a three-dimensional chromatogram in a conventional chromatographic data processing apparatus, processing is performed in the following procedure.

(1) In order to obtain a chromatogram in which a peak corresponding to a target component contained in a sample appears, a measurer must use one or more appropriate wavelength conditions (the center value of the wavelength λ and the Input and set a wavelength table listing bandwidths). (2) Further, the measurer inputs and sets an identification table in which information such as the retention time for identifying the peak of the target component for the wavelength λ described in the wavelength table is written. Since parameters such as the retention time greatly vary depending on analysis conditions such as the flow rate of the liquid and the type of column, the parameters are generally created or calibrated using the result of previously analyzing a standard sample containing a certain amount of a known component.

(3) At the time of measurement, a measurer inputs and instructs which wavelength in the wavelength table to use for each target component. (4) The data processing apparatus cuts out a two-dimensional chromatogram corresponding to the wavelength designated in (3) from the three-dimensional chromatogram as shown in FIG. 4, and applies the identification table to the two-dimensional chromatogram. Peak identification is performed according to the conditions described in (1). (5) When the peak is identified, a quantitative analysis is performed by executing arithmetic processing such as calculation of the area of the peak waveform.

[0006]

In the conventional data processing apparatus, it is necessary to perform the analysis in the above-described procedure. Therefore, especially when analyzing a sample containing a large number of components, a wavelength table is input and set. The operation of selecting the optimum wavelength for each component is complicated, and not only the work efficiency is deteriorated, but also an analysis error due to an input error may occur.

[0007] Further, since it is necessary for the measurer himself to judge the selection of the wavelength of the two-dimensional chromatogram to be used for the quantitative analysis, the criterion is not clear and the reproducibility of the analysis may be questionable. In such a case, it is necessary to repeat, for example, returning to the above (3), instructing another wavelength, and performing the processing again. Furthermore, since such an appropriate judgment requires a certain degree of skill, there is also a problem that those who can set analysis conditions are limited.

The present invention has been made to solve these problems, and an object of the present invention is to reduce the burden of an input operation by a measurer and to avoid ambiguity in setting analysis conditions. An object of the present invention is to provide a chromatographic data processing device.

[0009]

Means for Solving the Problems The present invention has been made to solve the above problems, and has been obtained by chromatography.
In a data processing device for processing data constituting a three-dimensional chromatogram comprising a time axis, an intensity axis and a wavelength axis, a) an area designating means for externally setting a two-dimensional area composed of time and wavelength; b) Component indicating means for externally indicating a peak corresponding to a target component included in the region, and c) a condition for externally indicating a determination condition for determining an optimum wavelength optimal for peak identification of the target component. Indicating means, d) for each predetermined wavelength step in the region, a chromatogram cutting means for cutting out a two-dimensional chromatogram including a time axis and an intensity axis, and e) for each of the cut out chromatograms, the component indicating means. Computing means for calculating an index value for comparison based on the judgment conditions specified by the condition specifying means, based on the peak specified by the above and the peak waveforms before and after the peak. F) wavelength determining means for comparing the index values of the chromatograms to determine the optimum wavelength; andg) the purpose of displaying the determined optimum wavelength in a wavelength table and appearing in a two-dimensional chromatogram cut out at the optimum wavelength. Storage means for storing the retention time corresponding to the peak top of the component in the identification table.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a data processing apparatus according to the present invention, for example, an operator refers to a three-dimensional chromatogram drawn on a screen of a display or a predetermined graph drawn based on the chromatogram data. Inputs a two-dimensional region surrounded by a time range and a wavelength range including a peak of a target component by a region designating means. Further, the peak corresponding to the target component existing in the area is designated by the component designating means. To facilitate such instructions,
When an area is designated by the area designating means, a local maximum point showing a value larger than the value before and after the area in the time axis direction and the wavelength axis direction is searched for in the area, and this is displayed on the display screen. .

Further, the operator instructs, by the condition instructing means, judgment conditions for determining the optimum wavelength for identifying the peak of the target component. The determination condition may be any one of an area ratio, a height ratio, a degree of separation, and the like between a peak of a target component and peaks before and after the target component in a two-dimensional chromatogram including a time axis and a relative intensity axis. The chromatogram extracting means cuts out a plurality of two-dimensional chromatograms at predetermined steps in the area. The calculating means finds a peak corresponding to the target component in each two-dimensional chromatogram, calculates an index value for performing comparison under the above-described determination conditions from the waveform of the peak and the peaks before and after the peak, and the wavelength determining means, The index value of each chromatogram is compared, and the wavelength having the best index value is determined as the optimum wavelength. Then, the storage means stores the optimum wavelength in the wavelength table and the retention time corresponding to the peak top of the target component appearing in the two-dimensional chromatogram cut out at the optimum wavelength in the identification table. As a result, the optimal wavelength for analyzing the target component and the optimal retention time for identifying the target component on the chromatogram of the wavelength are stored in the storage means. Identification and quantitative analysis of the target component contained in the target can be performed.

[0012]

As described above, according to the chromatographic data processing apparatus of the present invention, the wavelength table and the identification table are automatically created based on the data collected by the chromatograph. It becomes unnecessary for the measurer himself to manually enter these tables. For this reason, the analysis efficiency is improved, and an erroneous analysis due to a simple input error can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a data processing apparatus for a chromatograph according to the present invention will be described below with reference to FIGS.
FIG. 1 is an overall configuration diagram of an LC analyzer including a data processing device according to the present embodiment. This LC analyzer is roughly divided into an analyzer 10 and a data processor 20. The analysis unit 10 includes a liquid sending unit 11 including a liquid sending pump 12 and a liquid sending unit 1.
Injector 13 for injecting a sample into the mobile phase delivered from 1 and column oven 14 containing column 15
A PDA detector 16 provided at the outlet of the column 15;
It comprises an interface unit 17 including a D conversion circuit and the like, and a control unit 18 for controlling the operation of each unit.

On the other hand, the data processing unit 20 is embodied by a well-known personal computer, and a storage unit 22 such as a hard disk or a floppy disk is connected to a main processing unit 21 including a CPU and a ROM. 23, a display 24 serving as a display means
And an input unit 25 such as a keyboard and a mouse. The main processing unit 21 receives the detection data sent from the detector 16 via the interface unit 17, and performs a data processing function of analyzing the received data and an operation of each unit of the analysis unit 10 via the control unit 18. It also has a function to control the whole system. These functions are achieved by executing various programs incorporated in the main processing unit 21.

When performing the chromatographic analysis in the above apparatus, first, a mobile phase is supplied to a column 15 at a constant flow rate by a liquid sending pump 12, and a sample liquid is injected into the mobile phase from an injector 13 to perform column analysis. Send to 15.
While the injected sample passes through the column 15, each component in the sample is separated with a different retention time. PDA
The detector 16 detects each component eluted from the column 15 by dispersing it in the wavelength direction at predetermined time intervals. This detection signal is converted into a digital signal by the interface unit 17, sent to the main processing unit 21, and stored in the storage device 22. Data constituting such a three-dimensional chromatogram (see FIG. 3) including the time t, the relative intensity S, and the wavelength λ is stored in the storage device 22 as a data file 221 for each analysis.

In the data processing apparatus of this embodiment, the following processing is useful for analyzing unknown samples by utilizing the results of chromatographic analysis of samples having known components, such as standard samples. The wavelength table and the identification table can be created automatically. Hereinafter, the processing procedure will be described with reference to the flowchart of FIG.

First, the main processing unit 21 reads a data file 221 which is an analysis result of a known sample from the storage device 22 and uses the data in the data file to set the vertical axis to wavelength λ and the horizontal axis to time t. , A contour display graph is created by connecting points of the same relative intensity S by a curve. Then, this is displayed on the screen 241 of the display 24 (step S1). FIG. 4A is a diagram showing an example of the contour display graph. A portion where the interval between the contour lines is narrow indicates that the gradient is steep. The operator designates the coordinates [t1, λ1] and [t2, λ2] of the two diagonal points via the input unit 25 so as to include the entire peak of the target component while visually checking the display screen. To set a rectangular processing area X (step S2).

When the processing area X is set in this way, the main processing unit 21 checks the state of the contour lines included in the processing area X and obtains the maximum point Ai (i = 1, 2,...) (Step S).
3). The maximum point is a point where the relative intensity is greater than the relative intensity of the surroundings (in the direction of the time axis and the wavelength axis). In the above example, three points A1, A2, and A3 are recognized as the maximum points. You. The main processing unit 21 lists the [time Ti, wavelength Λi] of each maximum point Ai as a candidate peak and displays it on the screen 241 of the display 24 (step S4). That is, in the above example, the maximum point A1 [T1,
# 1}, A2 [T2, # 2], A3 [T3, # 3] are listed. The operator looks at the display, selects the maximum point corresponding to the target component, and gives an instruction from the input unit 25 (step S5). Here, for example, since only two points A1 and A2 are the target components, they are selected. The unselected maximum point A3 is considered to be a peak of an unnecessary component contained in the sample or a peak corresponding to an impurity component mixed in the middle.

Next, the operator operates the input unit 25 to
The optimum wavelength determination condition is selected from the following three options (step S6). (i) The area ratio of the adjacent peaks is the largest. (ii) The height ratio of the adjacent peaks is the largest. (iii) The resolution of the adjacent peaks is the largest. Conditions can be used.

When any one of the above-described determination conditions is specified, the main processing unit 21 generates a two-dimensional chromatogram in the wavelength direction at each predetermined wavelength step Δλ in the processing area X set previously. Cut out (step S7). For example, chromatograms cut out at wavelengths λ = Λ1, Λ2, and λ3 are as shown in FIGS. 4B, 4D, and 4C, respectively. Then, in each of the two-dimensional chromatograms, the index value (area ratio) of the determination condition selected in step S6 for the peak existing near the time (T1 or T2) of the previously selected maximum point and the peaks before and after it. , Height ratio or degree of separation) (Step S)
8). In order to calculate the area ratio and the degree of separation of two partially overlapping peaks, a calculation method used in conventional quantitative analysis processing can be used.

Subsequently, the main processing unit 21 compares the plurality of index values obtained in this manner, and generates a chromatogram giving a maximum area ratio, a height ratio or a degree of separation with respect to the maximum point with respect to the target component. locate. Then, the wavelength of this chromatogram is set as the optimum wavelength ΔE for the target component (step S9). The wavelength at which the area ratio, the height ratio, and the degree of separation are maximized are not always the same.
Therefore, it is up to the operator to decide which decision condition is most appropriate.However, it is necessary to obtain the optimum wavelength ΛE under each condition while sequentially changing the decision condition, and select the most likely one. Can also.

In this manner, for each target component, the optimum wavelength ΔE and the peak top retention time t corresponding to the target component in the two-dimensional chromatogram cut out at the optimum wavelength ΔE are obtained as shown in FIG. Can be Therefore, as shown in FIG. 6, the value of the optimum wavelength ΔE is stored in the wavelength table in the storage device 22 in association with the channel number, and as shown in FIG. 7, the holding time and the channel number to be used are stored. It is stored in the identification table in association with each component name (step S
10). As a result, the wavelength table and the identification table store data that allows peak identification to be performed most appropriately under the determination conditions specified by the operator. Therefore,
By using such a wavelength table and an identification table,
Identification and quantitative analysis of the target component in the unknown sample can be appropriately performed.

In the above embodiment, the optimum wavelength is determined based on the chromatogram data obtained by one analysis. However, when the same sample is analyzed a plurality of times, the analysis results are slightly different. Often different. Therefore, in order to create a more reliable wavelength table and identification table, use the chromatogram data obtained by analyzing the same sample multiple times under the same analysis conditions, and consider variations in the wavelength direction and time axis direction for the same target component. Then, it is more preferable to perform a process of selecting the most probable optimum wavelength.

The embodiment described above is merely an example, and it is apparent that modifications and modifications can be appropriately made in accordance with the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a liquid chromatograph analyzer including one embodiment of a data processing device according to the present invention.

FIG. 2 is a flowchart illustrating a procedure of an automatic creation process of a wavelength table and an identification table in the embodiment.

FIG. 3 is a diagram showing an example of a three-dimensional chromatogram.

FIG. 4 is a diagram showing an example of a contour display graph and a cut-out two-dimensional chromatogram in the present embodiment.

FIG. 5 is a view showing an example of data acquired by the embodiment.

FIG. 6 is a diagram showing an example of a wavelength table created by the embodiment.

FIG. 7 is a view showing an example of an identification table created by the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Analysis part 11 ... Liquid sending part 13 ... Injector 15 ... Column 16 ... PDA detector 17 ... Interface part 20 ... Data processing part 21 ... Main processing part 22 ... Storage device 222 ... Wavelength table 223 ... Identification table 23 ... Input Output control unit 24 Display 25 Input unit

Claims (1)

[Claims] 1. A data processing apparatus for processing data constituting a three-dimensional chromatogram comprising a time axis, an intensity axis and a wavelength axis, which is obtained by a chromatograph, comprising the steps of: Area designating means for externally setting; b) component designating means for externally designating a peak corresponding to a target component contained in the region; c) determining an optimum wavelength optimal for peak identification of the target component. Condition instructing means for externally instructing a determination condition for performing, a) a chromatogram extracting means for extracting a two-dimensional chromatogram including a time axis and an intensity axis for each predetermined wavelength step in the region, and e). For each of the cut-out chromatograms, based on the peak specified by the component specifying means and the peak waveforms before and after the peak, the determination conditions specified by the condition specifying means are used. Calculating means for calculating an index value for performing the comparison, f) wavelength determining means for comparing the index value of each chromatogram to determine an optimum wavelength, and g) determining the determined optimum wavelength in a wavelength table. Storage means for storing, in an identification table, a retention time corresponding to a peak top of a target component appearing in a two-dimensional chromatogram cut out at an optimal wavelength, a chromatographic data processing device.