JP3289438B2 - Chromatography data processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processor having a function of identifying and quantifying sample components from chromatogram data detected by a gas chromatograph or a liquid chromatograph.

[0002]

2. Description of the Related Art When a sample is analyzed by a chromatograph such as a liquid chromatograph or a gas chromatograph, a signal outputted from a detector includes a background signal in addition to a detection signal of a sample component. In order to determine the retention time of a sample component from the chromatogram obtained by analyzing the sample and identify it, or to calculate the concentration of the sample component from the peak area of the sample component, a correction that subtracts the background from the chromatogram requires correction. May be required.

[0003] The background appears unique to each analyzer, regardless of the sample. For this reason, the background data for background correction is independent of the analysis of standard and unknown samples, and the analysis system is used under the same conditions as sample analysis by injecting only the solvent or flowing only the carrier without injecting the sample. The analysis for the generation of the background correction data for the operation of is performed.
After that, standard and unknown samples are analyzed, and the background data previously detected is subtracted from the obtained chromatogram data to obtain background-corrected standard and unknown data. Performs precise identification and quantification.

[0004]

Since it is necessary to perform one extra analysis of the background data to obtain a background chromatogram, the total analysis time becomes longer and the number of times of analysis increases. This degrades the column and requires additional carrier gas and solvent. Accordingly, an object of the present invention is to solve these problems by eliminating the need for an analysis operation for acquiring background correction data.

[0005]

FIG. 1 shows a data processing apparatus according to the present invention. This data processing device includes a data memory 2 for storing data of measurement results of at least two types of standard samples created so that the concentration ratio of each component is constant, and a standard sample data stored in the data memory 2. The background calculation unit 4 mathematically extracts the background from the data of the two types of standard samples and the concentration ratio of the two types of standard samples, and the background extracted by the background calculation unit 4 is used. After correcting the standard sample data stored in the data memory 2 to create a calibration curve data by using a calibration curve creating unit 6 and the unknown sample data by using the background extracted by the background calculation unit 4, An unknown sample data processing unit 8 for quantifying using the calibration curve data created by the calibration curve creating unit 6 is provided.

[0006]

In order to prepare a calibration curve, at least two types of standard samples prepared so that the concentration ratio of each component is constant are used. As the standard sample, one type of sample containing a plurality of sample components is prepared, and the sample is diluted in several steps to obtain a plurality of types of standard samples having a constant concentration ratio of each component. Standard sample analysis for obtaining a calibration curve is performed using such a standard sample, and the standard sample data is stored in the data memory 2. Background calculator 4
Then, two types of standard sample data are called from the standard sample data stored in the data memory 2 to extract the background. The background is included in all standard sample data at the same size regardless of the concentration of the sample components. Generally, a chromatogram can be represented by the following equation (1). Fi (t) = {αij · fj (t) + b (t) + ei (t) (1) where i means the i-th standard sample, j means the j-th component, and Σ means the component j Means to collect about. Fi (t) is the chromatogram of the i-th standard sample, fj (t) is the base chromatogram of component j, b (t) is the background, and ei (t) is the chromatogram of components not related to noise or quantification. It is. Two standard samples 1 and 2
Can be expressed by the following equations (2) and (3). F ₁ (t) = Σα ₁ j · fj (t) + b (t) (2) F ₂ (t) = Σα ₂ j · fj (t) + b (t) (3) Here, e ₁ (t), e ₂ (t) is omitted because it does not affect the quantification. The concentration ratio of each component of the standard sample 1 and the standard sample 2 is constant, and if this is k, then α ₂ j = k · α ₁ j. Therefore, the above equation (3) is transformed into the following equation (3a). F ₂ (t) = kΣα ₁ j · fj (t) + b (t) (3a) When the background b (t) is obtained from the equations (2) and (3a), the following equation (4) is obtained. It is obtained as follows. _{b (t) = (F 2} (t) -kF 1 (t)) / (1-k) (4) by such mathematical processing capable of extracting background from two chromatograms.

When three or more kinds of standard samples are prepared to obtain a calibration curve, the background b (t) is calculated by the number of combinations of selecting two kinds of data from three or more kinds of data. Therefore, by obtaining the average thereof, a more accurate background can be obtained.

[0008] Both chromatogram data and background data are functions of time t, and data is obtained from the detector as a function of time. Therefore, the above calculation can be performed for each time t. Once the background has been extracted by calculation, the subsequent processing is performed, as usual, by performing background correction on the standard sample data to create a calibration curve, and performing background correction on the chromatogram of the unknown sample. And perform quantification using a calibration curve.

[0009]

FIG. 2 shows a gas chromatograph 10 as an example of an analyzer to which the present invention is applied. A sample injection unit 12, a separation column 14, and a detector 16 are arranged along the flow path of the carrier supplied at a controlled flow rate by the flow control unit 11. The column 14 is accommodated in a column tank 15 and the temperature is controlled. The column 14 may be a capillary column or a backed column, and the detector 16 may be a TCD, an FID, or another detector. The type of each part constituting the gas chromatograph The structure and the structure are not limited in the present invention, and can be applied to all the various types used so far. Further, the present invention is applied not only to gas chromatographs but also to liquid chromatographs.

A detection signal is obtained from the detector 16 as an analog signal, and a data processing device 18 is provided for creating a calibration curve from the detection signal and identifying and quantifying an unknown sample. The present invention is an improvement of the data processing device 18. Even if the present invention is applied to a liquid chromatograph instead of a gas chromatograph, detector data similar to that of a gas chromatograph can be obtained from a detector of the liquid chromatograph, so that the present invention can be similarly applied as a data processing device. .

FIG. 3 shows the configuration of the data processing device 18. A CPU 20 is provided to capture data from the detector and control various processing operations on the data. An A / D converter 22 for converting an analog signal from a detector of the chromatograph 10 into a digital signal and taking it into a bus line 21 of the CPU 20,
ROM 24 for storing operation procedures, RAM 26 for temporarily storing fetched data, floppy disk drive 28 for storing data to be stored, and instructions for operation and for setting the concentration ratio of each component of the standard sample. A keyboard 30, which is an input unit, and a CRT 32 and a plotter 34 for outputting obtained chromatograms and results of identification and quantification are connected.

Here, comparing the data processing apparatus shown in FIG. 3 with each section shown in FIG. 1, the data memory 2 shown in FIG. 1 is realized by a floppy disk drive 28, and the background calculation section 4, the calibration curve creating section 6, and the unknown sample Data processing unit 8
Is realized by the CPU 20, the ROM 24, the RAM 26, the floppy disk device 28, and the like.

The operation in the case of using two types of standard samples in which the concentration ratio of each component is k in one embodiment will be described with reference to FIG. 4 and FIG. FIG. 4 shows a calibration curve creation operation. When the analysis of the standard sample is started,
The standard sample data is stored in the memory. When the analysis of the two types of standard samples is completed, the background data is extracted by equation (4). Using the extracted background data, waveform processing is performed on the standard sample 1 and the standard sample 2 by background correction. The peak is identified from the chromatogram of the standard sample after the background correction, and the calibration curve data of the identified component is calculated.

FIG. 5 shows the operation of analyzing an unknown sample. The detection signal of the unknown sample is subjected to waveform processing while being subjected to background correction using the previously obtained background data. When the background-corrected chromatogram of the unknown sample is obtained, the concentration of each component of the unknown sample is calculated from the calibration curve data previously obtained. If there are multiple unknown samples, the analysis is repeated until all registered unknown samples have been analyzed.

[0015]

According to the present invention, the data for background correction is calculated by using the chromatogram data of the standard sample for preparing the calibration curve, instead of performing the analysis operation without injecting the sample as in the prior art. Since the ground data is extracted, the analysis for the background correction can be omitted. As a result, the total analysis time is reduced. In addition, since the number of times of analysis is reduced by one time, the rate of column deterioration is reduced, and the carrier gas and the solvent necessary for one time of analysis can be saved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the present invention.

FIG. 2 is a flow chart showing a gas chromatograph as an example to which the present invention is applied.

FIG. 3 is a block diagram illustrating a data processing device according to an embodiment;

FIG. 4 is a flowchart showing a calibration curve creation operation in one embodiment.

FIG. 5 is a flowchart showing an unknown sample measuring operation in one embodiment.

[Explanation of symbols]

 2 Data memory 4 Background calculator 6 Calibration curve generator 8 Unknown sample data processor

Claims (1)

(57) [Claims] 1. A data processing apparatus having a function of converting a signal output from a chromatograph into digital data and storing the data in a storage device and a function of quantifying a sample component, wherein a concentration ratio of each component is constant. A data memory for storing data of measurement results of at least two types of standard samples, and data of two types of standard samples among the standard sample data stored in the data memory; A background calculator that mathematically extracts the background from the concentration ratio of the standard sample, and a standard curve data obtained by correcting the standard sample data stored in the data memory using the background extracted by the background calculator. Using the calibration curve creation unit that creates the data and the background extracted from the unknown sample data by the background calculation unit After having corrected, the data processing apparatus being characterized in that and a unknown sample data processor quantified using the calibration curve data created by the calibration curve creating unit.