JPH09269319A - Data processor for quantitative analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a data processor whose analytical efficiency is enhanced by a method wherein, according to the shape of a peak, an area method or a height method is selected so as to perform a quantitative analysis. SOLUTION: Data (reference data) on a standard sample is stored in a storage part 16. When the measurement of the standard sample is started, a tailing-factor judgment part 18 computes a tailing factor on the basis of computed data on a peak, it judges whether the factor satisfies a prescribed condition or not, and it sends a result to a central control part 14. The central control part 14 refers to the result, it sends detection data on a symmetric peak to both a height determination part 20 and an area determination part 22, and it sends detection data on other peaks to only the area determination part 22. When the detection of peaks of all samples is finished, the central control part 14 sends the reference data to both determination parts 20, 22. A working curve A is created in the height determination part 20, and a working curve B is created in the area determination part 22. When an unknown sample is analyzed, a detection component is analyzed quantitatively on the basis of the working curve A in the height determination part 20 when the tailing factor satisfies the prescribed condition. When the factor does not satifiy the condition, the detection component is analyzed quantitatively on the basis of the working curve B in the area determination part 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device used for quantitative analysis such as chromatography.

[0002]

2. Description of the Related Art In the quantitative analysis of a sample, the peak of the signal output from the detector is analyzed by an appropriate method to obtain the amount of the component corresponding to the peak. In the data output by a general detector, since the peak area corresponds to the amount of the detected component, the quantification is usually performed based on the peak area. However, when the shape of the peak is bilaterally symmetric or close thereto, a method of obtaining the component amount based on the height of the peak is also used. Hereinafter, the above two methods will be referred to as an “area method” and a “height method”, and the shape of the peak when the peak has a symmetrical shape or a shape close to the symmetrical shape is called a “correct shape”.

The above two methods will be described with reference to the drawings. FIGS. 3A and 3B are examples of peak portions of chromatograms obtained by chromatographic analysis. The horizontal axis represents the elapsed time t after the sample is injected into the sample cell, and the vertical axis represents the output signal intensity I of the detector. FIG.
The peak A shown in (a) has a correct shape.
Such peaks can be quantified by both the height method and the area method. On the other hand, since the peak B shown in FIG. 3 (b) causes so-called tailing, it is not appropriate to quantify it by the height method and must be quantitated by the area method. This also applies to the peak causing the reading.

On the other hand, when two peaks are overlapped as shown in FIG. 4, it is not possible to obtain the correct area for each individual peak. It is necessary to further separate the components by such means. However, if the peak has a correct shape, the component can be quantified by the height method without separating the component.

In view of the above circumstances, conventionally, for example, a quantitative analysis of a sample is first carried out by a height method, and if a peak causing reading or tailing is detected,
In order to correctly quantify the peak, the components were quantified by the procedure of requantifying the same sample by the area method.

[0006]

In the analysis using the conventional apparatus, in order to properly use the quantitative method as described above depending on the shape of the peak, the operator must determine the shape of the peak and then manually operate the apparatus. It was necessary to operate and switch the quantitative method. In this method, in particular, when both a correctly shaped peak and an incorrectly shaped peak are detected during one analysis, the peak shape is determined for each individual peak and the quantitative method is selected. It was necessary and troublesome.

Further, for example, when an analysis is carried out by the height method using a deteriorated analyzer, the shape of peaks is largely changed due to the deteriorated constituent members, and some peaks are correctly measured by the height method. Occasionally, the results will not be obtained. In such a case, conventionally, it was necessary to switch the quantification method to the area method for requantification.

The present invention has been made to solve such a problem, and its object is to select an area method or a height method according to the shape of a peak to perform a quantification work. The object of the present invention is to provide a data processing device that can be performed more easily than before.

[0009]

The data processing apparatus for quantitative analysis according to the present invention made to solve the above-mentioned problems is a) detecting peak start points and peak end points according to a predetermined standard, and And b) tailing factor calculation means for calculating the tailing factor, which is a parameter related to the shape of the peak, based on the peak data, and c) quantification of the components by the height method based on the peak data. Based on the height quantifying means to be performed, d) Area quantifying means to quantify the components by the area method based on the peak data, and e) Based on the value of the tailing factor, the component to either the height quantifying means or the area quantifying means And a quantitative method control means for performing quantitative determination of.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the data processing apparatus for quantitative analysis according to the present invention, when the peak data detected by the peak detecting means is sent to the tailing factor calculating means, the tailing factor calculating means Whether or not the shape is correct is determined based on the tailing factor obtained by a predetermined method. This determination result is sent to the quantitative method control means. If the obtained tailing factor satisfies a predetermined condition, and therefore the peak shape is determined to be correct, the quantitative method control means causes the height quantitative means to quantify the peak. On the other hand, when it is determined that the tailing factor does not satisfy the predetermined condition, the quantitative method control means causes the peak area quantitative means to quantify the peak.

[0011]

According to the data processing apparatus for quantitative analysis of the present invention, peaks having the correct shape are quantified by the height method, and tailing or reading occurs to the extent that correct results cannot be obtained by the height method. Since peaks are quantified by the area method, correct data can always be obtained regardless of the peak shape. In the present invention,
Since the quantification means is automatically selected, the troublesome work of manually switching the quantification means according to the shape of the peak is unnecessary, and the efficiency of analysis is improved. Of course, even when the shape of the peak changes due to deterioration of the device, etc., according to the present invention, an appropriate quantification method is selected according to the change in the shape of the peak. There is no need to requantify the area by the area method.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of one embodiment of the quantitative analysis data processing apparatus according to the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the outline of the data processing apparatus according to this embodiment. The present data processing device quantifies the detected components by applying the data obtained based on the output signal from the detector 10 to a calibration curve, and the A / D conversion unit 12, the central control unit 14, and the storage unit. Part 1
6, tailing factor determination unit 18, height quantification unit 2
0, an area quantification unit 22, an input unit 24, and a display unit 26. Central control unit 14, tailing factor determination unit 1
8. The height quantification unit 20 and the area quantification unit 22 can each be configured by a program that operates on a microcomputer, but they may be configured by dedicated hardware. A keyboard or the like can be used as the input unit 24, and a CRT, a printer, or the like can be used as the display unit 26.

An example of a procedure for preparing a calibration curve using this data processing apparatus and analyzing an unknown sample will be described with reference to FIG.

First, as preparation for preparing a calibration curve, a plurality of standard samples with known component amounts are prepared, and data relating to the component amounts and peak top positions of the samples (hereinafter,
The “reference data”) is stored in the storage unit 16 through the input unit 24. In addition, the reference data regarding the standard sample group including the plurality of standard samples may be stored in the storage unit 16 in advance, and the data corresponding to the prepared standard sample may be read when the calibration curve is created.

When the measurement of the standard sample is started and the detector 10 outputs an electric signal, the outputted electric signal is successively digital data (hereinafter referred to as "detection data") by the A / D converter 12 at predetermined short time intervals. And are input to the central control unit 14. The central control unit 14 sequentially stores the input detection data in the storage unit 16, monitors the change in the value of each detection data, and determines the start and end of the peak based on a predetermined reference (step S12). Then, when the end of one peak is determined, the central control unit 14 stores the detection data obtained from the peak in the storage unit 1.
The data is read from No. 6 and sent to the tailing factor determination unit 18. The tailing factor determination unit 18 obtains the position (time) of the peak top of the peak formed by the detection data, calculates the tailing factor F by a predetermined method (step S14), and obtains the obtained tailing factor. It is determined whether or not F satisfies a predetermined condition (step S16), and the determination result is sent to the central control unit 14. The central control unit 14 refers to the determination result from the tailing factor determination unit 18, and sends the detection data of the peak determined to have the correct shape to both the height quantification unit 20 and the area quantification unit 22 (step S18). , S20) On the other hand, the detection data of the peak determined not to have the correct shape is sent only to the area quantification unit 22 (step S2).
0). The steps S12 to S20 are repeated until the peaks of all the components are detected, and when the detection of the peaks of all the standard samples is completed (step S22), the central control unit 14 outputs the reference data to the height quantification unit 20 and It is sent to the area quantification section 22, and the height quantification section 20 creates a calibration curve A for quantification based on the height of the peak.
Creates a calibration curve B for quantification based on the peak area (step S24).

A method of calculating and determining the tailing factor F in the tailing factor determining section 18 will be described with reference to FIG.

The tailing factor determining section 18 first forms a peak based on the detection data sent from the central control section 14, and obtains the peak top height H1 and the peak top position tp. Next, from the baseline, k% of H1
The peak width wk at the height (for example, k = 5) is obtained. That is, the position of the data closest to H2 of H2 = k.times.H1 / 100 is obtained in the first half and the second half of the peak top, and they are set to t1 and t2, respectively, and wk is obtained by the equation wk = t2-t1. Furthermore, the width wt of the first half of the peak is
It is obtained by the equation wt = tp-t1. From these numbers, for example tailing
The factor F is defined by the equation F = wk / (2 × wt). The tailing factor F takes a larger value as the degree of tailing increases, and takes a smaller value as the degree of reading increases. Therefore, the upper limit value Ct and the lower limit value Cl of F are set in advance, and the tailing factor determination unit 18 determines whether or not the calculated value of F is within the allowable range defined by the above Ct and Cl, that is, F is It is determined whether or not the following conditional expression Cl <F <Ct is satisfied, and the determination result is determined by the central control unit 14.
Return to When it is determined that F satisfies the above conditional expression,
The central control unit 14 sends data to the height quantification unit 20, and otherwise sends data to the area quantification unit 22. In addition,
The tailing factor can, of course, be determined by a method other than the above, and may be obtained from the ratio of peak areas before and after the peak top, for example.

Next, a procedure for subsequently analyzing an unknown sample when it is determined that the calibration curve A is usable in step S26 will be described. From the start of the analysis of the sample (step S30) to the calculation of the tailing factor F (steps S32 to S36) are the same as steps S12 to S16. Step S36
In the case where the tailing factor determination unit 18 determines that F satisfies the above conditional expression, the central control unit 14 sends the detection data to the height quantification unit 20, and the height quantification unit 20 makes the calibration curve A previously created. Is used to quantify the detected component (step S38). On the other hand, when the tailing factor determination unit 18 determines that F does not satisfy the conditional expression in step S36, the central control unit 14 sends the detection data to the area quantification unit 22, and the area quantification unit 22 creates it first. The detection component is quantified using the calibration curve B (step S4).
0). For example, when the chromatograph as shown in FIG. 5 is obtained, the peak C having the correct shape is quantified by the height quantification unit 20, and the tailing peak D and the leading peak E are obtained. Is quantified by the area quantification unit 22. The result of the quantification is sent to the central control unit 14, and the central control unit 14 displays the result on the display unit 26.

[Brief description of drawings]

FIG. 1 is a flowchart showing a procedure for analyzing a sample using a data processing device according to the present invention.

FIG. 2 is a block diagram showing a configuration of an embodiment of a data processing device according to the present invention.

FIG. 3 shows (a) a peak having a correct shape, and (b) a tailed peak.

FIG. 4 is a diagram showing how two peaks overlap.

FIG. 5 is a diagram showing a chromatogram including a peak having a correct shape, a tailing peak, and a leading peak.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Detector 12 ... A / D conversion part 14 ... Central control part 16 ... Storage part 18 ... Tailing factor determination part 20 ... Height quantification part 22 ... Area quantification part 24 ... Input part 26 ... Display part

Claims (1)

[Claims] 1. A peak detecting means for detecting a peak start point and a peak end point according to a predetermined standard to identify peak data, and b) a tailing factor which is a parameter relating to a peak shape based on the peak data. Tailing factor calculation means for calculating, c) height quantification means for quantifying components by height method based on peak data, and d) area quantification means for quantifying components by area method based on peak data And e) a quantitative analysis data processing device comprising: a height determination means or an area determination means for determining a component based on the value of the tailing factor.