JPS6279359A - Chromatograph data processing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid chromatograph, and particularly to a data processing device for a romatograph suitable for performing peak processing in large quantities using an autosampler.

[Background of the invention]

Generally, whether it is liquid chromatography or gas chromatography, it is aimed at separation analysis. Therefore, the first objective is to obtain a chromatogram. By looking at this chromatogram, it is determined whether the separation analysis has achieved the initial objective. Therefore, if the chromatogram does not meet the initial objective, for example, the separation between peaks is insufficient, or the number of peaks is insufficient compared to the expected number of components, separate analysis should be performed. It doesn't matter. Even if the position and area of this peak are calculated using a data processing device, the above calculation results will only be useful if the chromatogram is normal. The chromatogram also provides a good indication of the condition of the device.

That is, if there are ripples in the column temperature or ripples in the mobile phase, the ripples will appear on the baseline of the detector and will be detected as many peaks. Furthermore, if the separation column deteriorates or if the packing material becomes clogged and a gap is created at the inlet of the column, the peak width will widen and change, allowing the chromatogram to be drawn freely.

On the other hand, if you have already drawn a picture with a low range as shown in Fig. 6 and want to enlarge some of the peaks later on, you can also draw with a high range as shown in Fig. 7.

Furthermore, in a chromatogram, the chromatogram, position, and area information are combined to provide analysis result information.

When making a chromatogram into a report, etc. 1. The length of the time axis varies depending on the analysis method, and when copying, etc., it may not fit in the L1 section of the specified paper. Conventionally, in such cases, a reduction copying machine was used to reduce the size, but with this, both the time axis and density transfer were reduced at the same time. For example, if the time axis of the chromatogram in FIG. 6 is reduced to 172.1/4, chromatograms as shown in FIG. 8(A) and FIG. 8(I3) can be drawn.

In this way, it is natural that chromatograms of all components are required in separation analysis using chromatography, but when peaks are close together, separation may be insufficient or the peak height may become low. The disadvantage is that the accuracy of analysis deteriorates. Are these things chromatograms? This is information that can only be obtained by looking.

Conventional data processing equipment for liquid chromatographs has two methods: one that records detector output online and stores area values, and the other that stores instantaneous values over the entire interval while recording online and can reproduce chromatograms online. However, the former has the disadvantage that the device is small and inexpensive, but the chromatogram cannot be reproduced, while the latter can reproduce the chromatogram, but the device is large and expensive. For example, FIG. 3 of Japanese Patent Publication No. 54-19319 is a system diagram of a conventional liquid chromatograph.

The eluent 1 passes through a solenoid valve 2 and enters a separation column 5 via an automatic sample introduction device 4 by means of a pump 3 . The eluate separated into each component by the separation column 5 enters the detector 6. The detector 6 measures absorbance with a photometer.

The absorbance output signal of the detector 6 enters an integrator 7.

The integrator 7 uses the printer 8 to draw a chromatogram 8a from the online signal. When the analysis of one sample is completed, the peak position, integral value, etc. 8b are printed on the printer.

In this way, samples are sequentially introduced into the automatic sample introduction device 4, and while the chromatogram and integral values are printed out, information regarding the integral values is also sequentially stored in the storage device 7a in the integrator 7. This will be explained using diagram 8g4.

Beak P! and P2 indicate a part of the chromatogram.

The mermaid is the start point of the rise of the beak P1, and point B is the end point of the rise and also the start of the fall. Point C is both the end point of the fall and the start point of the rise of the peak P2.

Peak P now! To explain, the integrator 7 has an area A
BC...(Sl) and retention time r.

Tb, T. and peak height 1. ,Ib,I. I remember.

There are two ways to find the area of the beak Pi: the perpendicular segment method and the tangential segment method.

The perpendicular division method is for finding the area ABCC', and the tangential division method is for finding the area ABC. And these can be found as follows.

ABCC' = ABC,,-Person C'6.
...IABC=ABC,,-ACe,
-2 Of course, the surface and product value are ABCC'nABC.

Depending on the sample and conditions to be analyzed, the analyst decides whether to calculate the area using the perpendicular division method or the tangential division method, and recalculation can be performed in various ways.

In any case, the integral value and starting point of the area ABC,,
If you know the time of the end point, you can calculate the area using various methods, but there is a drawback that you cannot draw a chromatogram online.

Therefore, the method shown in Figure 5 was adopted. Peak height 'I
+'2...i, is stored for the entire analysis time. With this method, information regarding the chromatogram and integral values can be obtained even after the analysis is completed, but there is a patent that features a huge storage device 9 instead.

Now, I will explain about this storage capacity. The absorbance signal from the detector 6 is synchronized with 10m5EC and converted into a 3-byte numerical value.The sample is an amino acid protein hydrolyzate, the analysis time is 70 MIN, and the automatic sample introduction device 4 is used to analyze a series of 100 samples. When analyzing, the storage capacity m is m=3x100x60x70xI00=1260000
00, which had the disadvantage of requiring a device with a huge storage capacity of 126MB (megabytes).

[Purpose of the invention]

An object of the present invention is to provide a chromatographic data processing device that can create a chromatogram with all peaks in a normal distribution curve without increasing memory capacity.

[Summary of the invention]

The present invention focuses on the fact that in a completely separated chromatogram, the peak elution distribution from the separation column is a normal distribution, and calculates the distance between two points by knowing the peak height and peak width. The idea is to create a normal distribution chromatogram by creating a curve.

[Embodiments of the invention]

Examples of the present invention will be described below.

FIG. 1 shows an embodiment of the invention.

The information from the integrator 7 is the position and area of the peak. When information about the peaks shown in FIG. 4 is plotted, it becomes as shown in FIG. 4(A).

Now, the idea is to connect each point with a line that is faithful to the original drawing, but since there is no information about this section, there is no way to draw it.

However, it is generally known that the elution curve of a chromatogram of a chromatograph is normally distributed in principle. Therefore, if the width and height are known, a normal distribution curve can be drawn. Hit is the difference in retention time, and height is the difference in peak height.

Therefore, a normal distribution curve can be drawn between each point as shown in FIG. 4(B).

With the above method, a report containing a set of analysis information for a chromatogram can be created offline.

FIG. 2 shows a drawing flowchart. In the figure, T+ is the elution time, PJ is the peak height, Δt is the sampling period, H is the difference in peak height, Yu is the rise coefficient, and yn is the fall coefficient.

Suppose that if the data were recorded normally, a romatogram would be drawn as shown in Figure 6. However, it is not possible to accurately envision the chromatogram of a sample before analysis. For example, if the chromatogram in Figure 6 was recorded with the range set to 1, then if the range of the recording section was raised and the chromatogram was recorded at 2x, 5x, or 10x, then the chromatogram would appear in Figure 7(2) and Figure 7(B). , Figure 7 (C')
This means that we have obtained a romatogram. Figure 7 (C)
The number of peaks also decreases. Even if you copy a romatogram like this, you will only get the same one,
It has the disadvantage that it is absolutely impossible to draw a romatogram as shown in FIG. According to the invention.

Depending on the purpose of analysis, you may want to focus on only a specific component, even if you use an online romatogram as shown in Figure 7.

In such cases, it is natural to save data for the entire analysis time, but there are times when it is not necessary to draw a chromatogram for the entire analysis time. In such a case, according to the present invention, it is possible to draw only a specific section, so it is possible to draw a chromatogram for a report that suits the purpose of analysis.

It was explained earlier that a normal distribution curve is drawn between two points, but of course it may be a straight line or a sine wave curve.

Also, instead of using a drawing line between two points, divide the space between two points into n equal parts and
It is also possible to reproduce the chromatogram using the instantaneous values of the peak heights.

〔Effect of the invention〕

As explained above, according to the present invention, when an automatic sample introduction device is used in combination, the chromatograms of multiple samples can be stored using a normal distribution curve that is theoretically equivalent to the conventional method without requiring a huge storage device. It can be regenerated at its peak, making it extremely economical.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the reproduced image according to the present invention, Figure 2 is a flowchart, Figure 3 is a system diagram of a liquid chromatograph, and Figure 4
The figure is a diagram explaining how to find the area by object division and tangential division, and Figure 5 is a diagram explaining how to memorize the instantaneous values of all peaks.
FIG. 6, FIG. 7, and FIG. 8 are chromatograms. DESCRIPTION OF SYMBOLS 1... Eluent, 3... Pump, 4... Automatic sample introduction device, 5... Separation column, 6... Detector, 7...
・Integrator, 8...Printer, 9...Extension memory.

Claims (1)

[Claims] 1. A means for storing the height and retention time of the peak rise start point, rise end point, fall start point, and fall end point of the peak of the chromatogram, as well as the area values of these sections, and to store the chromatogram online. What is claimed is: 1. A chromatographic data processing device comprising a recording means for recording data, characterized in that the chromatographic data processing device is provided with a means for offline creating an approximate chromatogram that sequentially connects each of the points with a straight line.