JP3700368B2 - Chromatographic data processor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chromatographic data processing apparatus for analyzing and processing data acquired by liquid chromatographic analysis or gas chromatographic analysis, and more particularly, when a plurality of samples are continuously measured, The present invention relates to a chromatographic data processing apparatus suitable for so-called overlap injection, in which the next sample is introduced into a column before being completely discharged from the column.
[0002]
[Prior art]
In a liquid chromatographic analyzer (hereinafter referred to as “LC analyzer”), an eluent is allowed to flow through a column at a constant flow rate, a sample liquid is injected into the eluent, the sample liquid is introduced into the column, and the column is Each sample component that is separated and eluted in the time axis direction while passing is detected by a detector provided at the column outlet. The signal detected by the detector is analyzed by a data processing device using a personal computer or the like, and a chromatogram is created with the elapsed time on the horizontal axis and the relative signal intensity on the vertical axis.
[0003]
In the chromatographic analysis, usually, a predetermined delay time is required until the components contained in the sample reach the column outlet after the sample is introduced into the column. Therefore, when collection of detection signals is started from the point of sample injection into the eluent and the elapsed time is zero on the chromatogram, there is no change in the chromatogram until the predetermined delay time has elapsed. Does not occur. Therefore, when measuring multiple samples continuously, the analysis can be performed more efficiently by using the so-called overlap injection method, in which the next sample is introduced into the column before the previous sample components are completely removed from the column. Can be done.
[0004]
FIG. 5 is a conceptual diagram showing the operation of overlap injection with the state of movement of the sample liquid in the column 15. In FIG. 5A, sample A is first introduced into the column 15, and each component in the sample A spreads in the longitudinal direction of the column 15 as shown in FIG. Sample B is introduced into the column 15 after a predetermined delay time. At this time, the most advanced component among the components in the sample A is far ahead of the sample B. Each component in the sample B introduced into the column 15 also spreads in the longitudinal direction of the column 15 as shown in FIG. However, if sample B is injected with a sufficient delay time, the most advanced component of sample B will not catch up with the end of sample A.
[0005]
That is, in the overlap injection, the retention time of each component in the sample is considered, and the overlap time is shorter than the retention time of the most advanced component in the sample B to be injected later, or Then, each sample injection is scheduled so as to be shorter than the holding time of the component in the sample B to be injected later that can be used for analysis and the component that advances most first. Of course, in this case, the detection signal for the sample B injected later cannot be acquired until the previous sample A finishes coming out of the column 15. Therefore, when data processing is performed, the chromatogram is created by offsetting the time from the injection point of sample B until the start of detection signal acquisition for sample B, that is, assuming that the detection signal is zero. There is a need to.
[0006]
6A and 6B are diagrams showing an example of a chromatogram created in a conventional data processing apparatus. FIG. 6A is a chromatogram for sample A, and FIG. 6B is a chromatogram for sample B. FIG. In FIG. 6, t1 is an overlap period, and the chromatogram for the sample A reflects the detection signal collected during the overlap period t1, and the chromatogram for the sample B shows the overlap period t1. The signal is zero (ie baseline).
[0007]
[Problems to be solved by the invention]
However, if the sample B contains an unexpected substance, some components important for analyzing the sample B may catch up with the last component of the sample A in the column 15. . For example, if the sample P is chromatographed alone, even if the peak Px shown in FIG. 6B appears in the chromatogram, the chromatogram of the sample B is not obtained in the analysis by the overlap injection. The peak Px does not appear above. For this reason, if the component of the peak Px is an important component in analyzing the sample B, the accuracy of the analysis is greatly impaired due to the lack of the peak Px. (Note that, on the chromatogram of sample A, the component corresponding to peak Px appears as peak PB, but when analyzing sample A, the influence of peak PB can usually be eliminated by appropriate processing.)
[0008]
The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to provide chromatographic data capable of creating a chromatogram that does not impair the accuracy of analysis even when, for example, overlap injection is performed. It is to provide a processing apparatus.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a chromatograph data processing apparatus for analyzing and processing a detection signal obtained by a detector of a chromatographic analyzer.
a) a data input channel to which the detection signal is input;
b) multiple data collection tasks each capable of starting data accumulation asynchronously;
c) a data branching unit that provides the data input to the data input channel in parallel to the plurality of data collection tasks;
d) control means for giving an instruction to start and end accumulation to each of the plurality of data collection tasks;
It is characterized by having.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The chromatographic data processing apparatus according to the present invention is effective, for example, at the time of analysis by overlap injection. When the first sample is injected in the chromatograph analysis unit during the overlap injection analysis, the control means instructs the first data collection task to start storing data. The first data collection task starts to store the detection signal (analog detection signal or data obtained by digitizing the signal) input to the data input channel via the data branching unit, for example, in a predetermined area of the memory. When the second sample is injected subsequent to the first sample in the chromatographic analysis unit, the control means instructs the second data collection task to start storing data. Therefore, the second data collection task starts to accumulate data after a predetermined time (difference between the injection times of the first and second samples) from the first data collection task. At this time, since the first data collection task continues to accumulate data, the same data is stored in the first and second data until the end of accumulation is instructed after the second sample is injected. Collected in both data collection tasks.
[0011]
For example, the data processing apparatus creates a chromatogram using the accumulated data while the first and second data collection tasks are accumulating data or after the accumulation is completed. Then, on the chromatogram for the first and second samples, a peak waveform having the same shape appears in the overlapped portion.
Therefore, any chromatogram can be reflected without loss of the peak from the sample injection.
[0012]
【Example】
An embodiment of a chromatographic data processing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an LC analysis system including a data processing apparatus according to the present embodiment. This LC analysis system mainly includes an LC analysis unit 10 that measures a sample and acquires data necessary for analysis, and data processing that performs qualitative analysis and quantitative analysis by performing predetermined waveform processing and arithmetic processing on the data. Part 20.
[0013]
The LC analyzing unit 10 includes a liquid feeding unit 11 including a liquid feeding pump 12, an auto injector 13, a column oven 14 including a column 15, a detector 16, an input interface unit 17 including an A / D converter, and the above parts. It comprises a controller 18 for sending an operation control signal. On the other hand, the data processing unit 20 is embodied by a personal computer, and includes a central control unit 21 having a CPU and the like, a display 22, a keyboard 23 and a mouse 24 as input means, an external storage device 25 such as a hard disk, an optical disk, and a memory card, The printer 26 is configured. Predetermined software is installed in the central control unit 21, and data collection processing as described later is achieved by executing the software on the CPU.
[0014]
FIG. 2 is a diagram functionally illustrating the data collection process in the data processing unit 20.
One data input channel 30 connected to the output of the input interface unit 17 is branched into a plurality of data collection tasks 31, 32, 33,... And connected in parallel. Each of the data collection tasks 31, 32, 33,... Has a function of sequentially writing data to the data storage areas a, b, c,... Reserved in the external storage device 25 or the memory inside the central control unit 21. Yes. The data collection control unit 34 instructs each data collection task 31, 32, 33,... To start and end writing independently (asynchronously). In the data collection tasks 31, 32, 33,..., Data collected between the writing start instruction and the ending instruction is normally stored as one file, and a chromatogram described later is created by analyzing this data. In addition, qualitative analysis and quantitative analysis are performed.
[0015]
FIG. 3 is a conceptual diagram showing a data collection operation when overlap injection is performed in the LC analysis system. The data collection operation will be described with reference to FIG. The measurer creates an analysis schedule by operating the keyboard 23 and the mouse 24 while looking at the screen of the display 22. The analysis schedule is for determining the analysis order of a plurality of samples, and sample name or sample number, sample injection amount, analysis time, overlap time, injection conditions, etc. are input and set.
[0016]
When the start of analysis is instructed, the central control unit 21 sends an instruction signal to the controller 18 to select and inject the first sample A according to the analysis schedule. Thereby, the auto injector 13 injects a predetermined amount of the sample A into the eluent sent from the liquid feed pump 12. The data collection control unit 34 sends a data collection start instruction to the first data collection task 31 simultaneously with the injection of the sample A (time ta in FIG. 3). The first data collection task 31 starts writing time-series data input to the data input channel into the storage area a.
[0017]
As shown in FIG. 5B, each component in the sample liquid A spreads in the longitudinal direction of the column 15 due to the difference in holding time while passing through the column 15. The central control unit 21 receives the sample A injection instruction at a time point (time tb in FIG. 3) that is traced back by the overlap time from the time point when the analysis time of the sample A has passed (time tc in FIG. 3). The controller 18 is instructed to select and inject the second sample B. The data collection control unit 34 instructs the second data collection task 32 to start data collection simultaneously with the injection of the sample B. Since data is given to the second data collection task 32 in parallel with the first data collection task 31, writing of the same time series data into the storage area b is started.
[0018]
If the analysis time of the sample A elapses after the sample A is injected, the data collection controller 34 sends an instruction to end data collection to the first data collection task 31 (time tc in FIG. 3). As a result, the first data collection task 31 stops writing the time-series data to the storage area a. As a result, the data obtained by the detector 16 from the start of the injection of the sample A until the analysis time elapses is stored in the storage area a. Similarly, in the storage area b of the second data collection task 32, the data obtained by the detector 16 until the analysis time elapses from the start of injection of the sample B is stored in the third data collection task 33. In the area c, data obtained by the detector 16 from the start of injection of the third sample C until the analysis time elapses is stored.
[0019]
FIG. 4 is an example of a chromatogram created using the data collected in this way, where (a) is a chromatogram for sample A and (b) is a chromatogram for sample B. Such a chromatogram creation process can be performed almost simultaneously with data collection, that is, in real time and displayed on the screen of the display 22, or only data collection is performed once and the accumulated data is used. It is also possible to create a chromatogram.
[0020]
In the chromatogram shown in FIG. 4B, unlike the conventional chromatogram shown in FIG. 6B, a peak waveform having the same shape as the overlap period t1 of the chromatogram of the sample A appears in the overlap period t1. ing. In this example, the component that passes through the column 15 most rapidly among the components contained in the sample B catches up with the component that passes through the column 15 the latest among the components contained in the sample A. Therefore, on the chromatogram shown in FIG. 4A, a peak PB due to the component of sample B appears in the overlap period t1. On the other hand, on the chromatogram shown in FIG. 4B, a peak PA due to the component of sample A appears in the overlap period t1.
[0021]
Thus, a peak due to a component not included in the sample can be regarded as a kind of noise. Therefore, by executing normal appropriate analysis processing, it is possible to eliminate unwanted peaks and perform qualitative analysis or quantitative analysis of the sample.
[0022]
Although the above embodiment has been described in the case of analysis by overlap injection, the use of the data processing apparatus according to the present invention is not limited to this. For example, a part of data can be collected by the second data collection task 32 during a period in which a certain long-time chromatographic analysis is performed and the data is collected by the first data collection task 31. . Thus, for example, when the specific peak appears on the chromatogram while the chromatogram is displayed on the screen of the display 22 while processing the data collected by the first data collection task 31 in real time, By operating the keyboard 23 or the mouse 24, another chromatogram having the peak as the starting point of the retention time can be created.
[0023]
Moreover, the said Example is an example and it is clear that a deformation | transformation and correction can be performed suitably in the range along the meaning of this invention.
[0024]
【The invention's effect】
As described above, according to the chromatographic data processing apparatus of the present invention, for example, even when overlap injection is performed, the data of the overlap portion can be reflected on the chromatogram of each sample. Therefore, a necessary peak defect is eliminated and each sample can be analyzed more accurately. In addition, since the degree of freedom of sample injection timing is increased, it is not necessary to perform strict sample injection scheduling as in the prior art. For this reason, the burden on the measurer is reduced.
[0025]
Further, conventionally, it is possible to adopt a configuration in which analog detection signals from a detector are introduced in parallel to a plurality of input interface units, and data is stored asynchronously by a data collection task corresponding to the input interface units. It was. However, in such a configuration, since it is necessary to prepare a plurality of input interface units and the cost increases greatly, it is rare that overlap injection is actually performed. On the other hand, according to the chromatographic data processing apparatus of the present invention, data acquisition of a plurality of channels can be performed asynchronously only by software, so that there is little increase in cost and it is easy to use overlap injection.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an LC analysis system including a chromatograph data processing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram functionally showing data collection processing of a data processing unit in the LC analysis system of FIG.
FIG. 3 is a conceptual diagram showing a data collection operation when overlap injection is performed.
FIG. 4 is a diagram illustrating an example of a chromatogram created by the data processing apparatus according to the present embodiment.
FIG. 5 is a conceptual diagram showing a movement state of a sample solution in a column at the time of overlap injection.
FIG. 6 is a diagram showing an example of a chromatogram created by a conventional data processing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... LC analysis part 13 ... Auto injector 15 ... Column 16 ... Detector 17 ... Input interface part 20 ... Data processing part 21 ... Central control part 22 ... Display 23 ... Keyboard 24 ... Mouse 25 ... External storage device 30 ... Data input Channels 31, 32, 33 ... data collection task 34 ... data collection control unit

Claims (1)

In the chromatographic data processing apparatus for analyzing and processing the detection signal obtained by the detector of the chromatographic analysis unit,
a) a data input channel for inputting the detection signal;
b) multiple data collection tasks each capable of starting data accumulation asynchronously;
c) a data branching unit that provides the data input to the data input channel in parallel to the plurality of data collection tasks;
d) control means for giving an instruction to start and end accumulation to each of the plurality of data collection tasks;
A chromatograph data processing apparatus comprising:

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