JPH0240981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chromatogram analysis and display device in a spectroscopic chromatographic detector.

When multiple types of devices are used as chromatographic detectors, analytical information can be obtained from the retention time of separated sample components as well as the sensitivity ratio between multiple types of detection means, which differs depending on the substance.
This is extremely advantageous in terms of discrimination of component substances, discrimination of insufficiently separated peaks, etc. However, when multiple types of chromatographic detection means are used, there is a problem in that the amount of data is large and the analysis is troublesome when data is analyzed later. The present invention seeks to solve this difficulty. Note that the selection of multiple types of detection means is arbitrary; for example, if multiple types of wavelengths of light are selected and a spectroscopic method is applied, detection data can be obtained for each selected wavelength, and a single spectrometer can be used. However, the same result as using multiple types of detection means can be obtained.

For example, sequential spectroscopic analysis of the chromatographic effluent fluid provides a record of changes in absorption for several selected wavelengths of light. In these records, a set of absorbance values for light of each wavelength at any given time can be considered as one vector. The purpose of the present invention is to record this vector and examine its temporal changes, making it easier to read various information from the data than recording a large number of absorbance changes. In other words, when considering a chromatogram as one pattern, pattern recognition becomes easier.

Now consider one peak in the chromatogram, and assume that this peak is a peak with complete component separation. Since the separation is complete, this peak represents a change in the concentration of a single substance, and the absorbance value for light at multiple appropriately selected wavelengths will follow the change in concentration from the rise of the peak to its extinction. change, but the mutual ratio of absorbance remains unchanged. In other words, the absolute value of a vector whose components are absorbance for each wavelength gradually extends from 0 until it reaches a maximum and then becomes 0 again, but the direction of the vector does not change and the record of the temporal change of the vector is a single line pointing in a fixed direction. In the straight line, only the length expands and contracts with time. Conversely, when the tip of the absorbance vector traces a curved trajectory over time, it can be determined that the peak is not a single substance. When two wavelengths are taken, the vector described above becomes a two-dimensional vector, and its temporal change can be recorded with an XY recorder. FIG. 1A is a record of vector changes in this case, and FIG. 1B is a normal chromatogram, and vector records for the three peaks of this chromatogram are shown in FIG. 1A. A peak is a completely separated peak, and the vector record is shown in Figure 1A.
As shown in , each is a straight line. Since the substances that exhibit these peaks are different from each other, the absorbance ratios for the two wavelengths are different, and therefore the lines A in FIG. 1 are straight lines in different directions. The peaks are incompletely separated peaks, and their vector record becomes a curve like that shown in FIG. 1A. This peak consists of two components, and the vectors of each component can be thought of as tangent lines a and b at the origin of this curve. Although the peaks of these components overlap, there is a lag in the time at which the peaks appear, and the rise and fall of the peak are each a single substance, and in the middle of the peak, the two substances are mixed with changing concentration ratios. Therefore, the recording of vectors becomes a curve that gradually shifts from, for example, the a vector to the b vector. If one peak is a combination of three component peaks, the vector record will have three protrusions, and depending on the temporal order in which the three components appear, it will look like the one shown in Figure 1C. It can also take on a complex shape. In this case, a, b, and c are the components that make up this peak, and it is said that the components flow out in the order of a, b, and c, or from c, b, and a. When three or more n detection means are applied, the vector is recorded by taking two data from the n data and recording it as a two-dimensional vector with an XY recorder, and recording the two data sets at maximum (n -1) Just assemble it and record it.

The above is the principle of the present invention. The present invention will be explained below with reference to Examples. FIG. 2 shows an embodiment of the present invention. 1 is a continuous spectrum light source, 2 is a condensing mirror, and 3 is a flow cell through which the chromatography column effluent fluid flows. 4 is a collimator mirror,
Reference numeral 5 denotes a diffraction grating, and 6 denotes a camera mirror. These collimator mirror 4, diffraction grating 5, and camera mirror 6 constitute a spectroscopic means for the light transmitted through the chromatograph outflow fluid. A plurality of photodetectors are arranged on the spectral image plane formed by this spectroscopic means. In this embodiment, one photodiode array 7 in which a large number of unit elements are arranged is used, and the plurality of addresses are The unit elements corresponding to the designated addresses are designated as the plurality of photodetectors. Cp is a control circuit, and in this example,
This is a means for sampling the outputs of the plurality of photodetectors mentioned above over time, and also serves as a means for controlling the recording means, and by sequentially specifying the elements of the photodiode array 7, the photometric output is recorded. The reading A-D converter AD converts the data into digital data and writes it to the address corresponding to the wavelength in the memory M1 or M2.The contents of the memory M1 and M2 are read and the necessary calculations are performed in the arithmetic circuit and the data is output to the XY recorder or XY plotter. The operation of recording the locus of the vector tip on a two-dimensional recording means such as R is controlled.

The above control operation of the control circuit will be specifically explained.
The control circuit Cp uses a built-in clock pulse oscillator to generate a clock pulse shown as Cl in FIG. 3, and starts reading the output of each element of the photodiode array 7 at the rising edge of the start pulse shown as St in FIG. In this case, the clock pulses are counted and the output of the i-th element of the photodiode array 7 is read out corresponding to the count i.
The photodiode array is scanned in this way, and this scanning is repeated between the falling edge of the th clock and the falling edge of the i+1 th clock. The clock count value i is data specifying an element on the photodiode array 7 and therefore corresponds to a wavelength. FIG. 3g shows the time variation of the analog data thus read out from the photodiode array 7, and the graph of FIG. 3g for one scan corresponds to a spectral image during that scan period. Cp performs AD conversion and logarithmic conversion of this analog data and writes it to the address corresponding to the counter count i of memory M1 or M2. Whether to write to M1 or M2 is determined by the program, and is determined as follows. First, the photodiode array 7 is scanned by flowing only the carrier fluid through the flow cell 3, and the data at that time is written into the memory M1. Next, the column outflow fluid is caused to flow through the flow cell 3, and the data from the photodiode array 7 at that time is written into M2. This M
2, new data is written each time the photodiode array 7 is scanned once. The scanning of the photodiode array 7 is repeated at a considerably high speed compared to the temporal changes in the chromatogram, so that the data in the memory M2 correspond to the moment-by-moment absorbance spectrum of the column effluent fluid. In this embodiment, a photodiode array is used as a plurality of photodetectors, and as a result, the output of the photodiode array is taken out at fixed time intervals, and in principle, the sampling interval is arbitrary in the present invention. Therefore, there is no inherent need for it to be a finite size.

The control circuit Cp controls the vector recording operation in the following manner in addition to controlling the above operation. Data at addresses corresponding to the two specified wavelengths λ1 and λ2 in the memories M1 and M2 are read out at appropriate time intervals.
The data written in M1 is the logarithmically converted value of the transmitted light intensity of the carrier fluid only, and the wavelength λ1,
Let the above data (logarithmically converted values) of the carrier fluid for each of λ2, that is, the data read from the memory M1, be A(λ1) and A(λ2).

The data in memory M2 is a logarithmically converted value of the transmitted light intensity of the mixture of carrier fluid and sample components, and the data read from M2 is
(λ2). Send these data to the arithmetic circuit Cu and calculate A(λ1)-C(λ1)=S(λ1) and A(λ2)-
C
(λ2)=S(λ2) is calculated, and S(λ1) is the X-axis coordinate value,
XY recorder or XY with S(λ2) as the Y-axis coordinate value
Input it into plotter R to record one coordinate point. That is, S(λ1) and S(λ2) are the absorbances of the sample components at wavelengths λ1 and λ2. The above operations are performed between the time when Cp finishes scanning the photodiode array 7 once and before starting the next scan. Therefore, this operation is instantaneous when viewed from the temporal change of the chromatogram, and by repeating this operation at appropriate time intervals, the absorbance values for the two wavelengths can be doubled.
A record of temporal changes in the component vectors is obtained, and this record has a pattern as illustrated in FIG. Although the wavelengths λ1 and λ2 may be specified as a unique set for the entire chromatogram, it is possible to change the combination of wavelengths for each peak and draw the chromatogram by guiding the column outflow fluid to a separate detector. The program may be configured so that each time the rise of the peak is detected, a different set of two wavelengths is specified and vector changes are recorded.

In the record of vector changes obtained by the present invention (Figure 1), the direction of the vector indicates the type of material,
Since the length indicates the concentration of the substance, this record is a qualitative/quantitative record, and if it is the same sample, it will be the same record, so it is easy to identify the sample by overlapping the two records and checking whether they match or not. . Furthermore, as mentioned at the beginning, the locus of vector change is a straight line if the separation is perfect, but if the locus covers an area, it can be determined that the separation is insufficient, and even for multiple overlapping components, there is no difference in the type of substance. A certain amount of information can be obtained.
In addition, since the record of the trajectory of vector change does not include a time component like a normal chromatogram and the pattern is simplified, it is possible to use a computer to determine whether two records are the same or whether the peak components are separated properly. is also easy. Furthermore, although the present invention requires the preparation of a plurality of detectors with different characteristics, it is difficult to find various types of detectors with different sensitivity characteristics for various components. However, in the present invention, since a spectroscopic detection means is used as a detector, a plurality of detectors with arbitrarily different characteristics can be prepared for one detection structure simply by selecting a wavelength.

[Brief explanation of the drawing]

FIG. 1 is an example of recording obtained by the device of the present invention, FIG. 2 is a block diagram showing the configuration of an embodiment of the device of the present invention, and FIG. 3 is a time chart regarding a part of the operation of the device. . 1... Light source, 3... Flow cell, 5... Diffraction grating, 7
…Photodiode array, Cp…Control circuit, AD
...A-D conversion and logarithmic conversion circuit, M1, M2...memory, Cu...arithmetic circuit, R...XY recorder or XY
Protsuta.

Claims (1)

[Claims] 1. A flow cell through which chromatograph outflow fluid flows, a spectroscopic means for dispersing light transmitted through this flow cell, and a plurality of photodetectors arranged at a plurality of arbitrary wavelength positions on a spectral image surface formed by this spectroscopic means. , a two-dimensional recording means, which samples the outputs of the plurality of photodetectors at arbitrary time intervals, stores the sampling data in a memory, and records the outputs of two of the plurality of photodetectors from the same memory. a control circuit that reads out two sets of data corresponding to the above, and an arithmetic circuit that calculates an X coordinate value and a Y coordinate value from the data corresponding to the two photodetectors read out according to a command from this control circuit. A chromatographic detection data processing display characterized in that the X-coordinate value output and Y-axis coordinate value output of the arithmetic circuit are used as the X-axis coordinate and Y-axis coordinate input of the two-dimensional recording means. Device.