JP2568311B2 - Chromatographic quantitative analysis method and apparatus - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a chromatographic data processing method and apparatus.

[Prior Art] Generally, in the quantitative analysis by chromatography,
Before measuring an unknown sample, measurement is first performed using a standard sample containing an expected component in the unknown sample or a component to be identified, and the retention time of the component in the analytical column is measured. Next, the peak intensity of each component is measured using one or more standard samples whose concentration is clear, and a calibration curve of the analytical component is determined from the concentration and the peak intensity. Thereafter, the unknown sample is measured, the component of the unknown sample is identified from the retention time of the peak, and the concentration is determined from the calibration curve from the peak intensity (Japanese Patent Laid-Open No. 57-108663).

In addition, for components whose unknown sample is known in advance but whose concentration is unknown, the retention time of each component is determined using a standard sample in the same manner as described above, and the standard sample is injected again and calibrated. The analysis was carried out in such a way that a line was determined and thereby quantified.

[Problem to be Solved by the Invention] Conventionally, in a quantitative analysis of an unknown sample in which the analysis component is known or the analysis component is specified, the standard sample is injected twice as described above, and the first identification is performed. The calibration curve was prepared for the second time, and the labor of the operation was not taken into consideration. This was a bottleneck in shortening the analysis time especially in routine work for measuring a large number of samples. The specific method of analysis of such routine work is to first measure the retention time of components using a standard sample, create a table of standard concentrations, and then inject the standard sample again and re-measure the standard. Create a line. That is, two operations (operations) were necessarily required.

An object of the present invention is to shorten the steps of identifying an analytical column with a standard sample and preparing a calibration curve in the analytical step.

[Means for Solving the Problems] The gist of the present invention for achieving the above objects is as follows.

(1) A method for quantitative analysis of a sample in which at least a component to be immobilized is specified by chromatography, wherein a predetermined amount of a standard sample containing a known amount of the identified component is injected only once into an analytical column, The retention time of the identified component and its peak intensity are measured simultaneously, and for a chromatogram peak having a higher peak intensity than a predetermined judgment level value, the identification of the component and a calibration curve thereof are obtained at once. Chromatographic quantitative analysis method.

(2) an injection means for injecting the sample into the analysis column;
A / D conversion means for converting an analog signal of the chromatograph from the column into a digital signal, and central processing for converting the digital signal into data of a predetermined format set by a command of a control command storage means and a control command means Means, a chromatographic quantitative analyzer having a signal data storage means for storing the data, wherein the control command storage means comprises a calibration curve creation table for quantification, and a component identification determination level setting means, The central processing unit measures and calculates the retention time of the identified component and its peak intensity by performing only one injection of the standard sample containing the known amount of the identified component from the injection unit, and calculates and identifies the component. A chromatographic quantitative analyzer having a function capable of calculating a value.

As described above, in the present invention, the component is identified and the calibration curve of the component is created only by injecting the standard sample once.

Specifically, first, a component table is created before the measurement of the standard sample. Then, the standard sample is measured, and the value of the calibration curve obtained from the retention time and the component area (or component peak height) of the identified component is set (described) in the component table.

For example, when analyzing a sample of three components including components A, B, and C, a chromatogram obtained by measurement can determine that the peak is the component A from the retention time of the component to be identified. , Set the chromatographic peak detection level. Since the standard sample is prepared with a predetermined component and a predetermined concentration, the peak of impurities is generally small. Therefore, 3 of A, B and C above
Components are identified as A, B, and C in order of peak outflow. When a component peak higher than (or higher than) the detection level is detected, a component table is set so that the first peak can be identified as A, the second as B, and the third as C. In this way, when all three components are detected, A and its retention time, B and its retention time, and C and its retention time are determined. Since the component concentrations of A, B, and C at this time are also determined, a calibration curve can be obtained simultaneously from the magnitude of each peak.

The calibration curve (calculation of the correction coefficient) is obtained by the following equation.

[Action] The reason why the identification time of the analytical column for the quantitative analysis by the chromatograph of the present invention using the standard sample can be shortened is that the standard sample is injected only once and the identification and the preparation of the calibration curve can be performed simultaneously.

Further, the reason why the creation of the analysis table is easier (it is easier to automate) is that the identification determination level is set.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

An analog signal from the chromatograph is converted from an analog signal to a digital signal via an A / D converter 9,
It enters the central processing unit 4 via the peripheral device connector 5. Then, according to a command from the control command storage 1, the data is converted into data of a predetermined format set by the control command storage 6 and stored in the signal data storage 2. On the other hand, when this signal reaches a certain amount, it is printed by the output device 8. These operations are repeated to obtain the chromatogram shown in FIG. Hereinafter, this repetition continues until the end of the analysis. By setting the determination level of the identification component to a certain level or higher by the identification determination level setting device 7, the peak due to impurities can be cut. If the identification determination level is set to a predetermined level and stored in the identification determination level storage, there is no need to set it each time measurement is performed. The component name can be input in advance using the identification component name input device.

After the analysis of the standard sample is completed, the concentration is calculated according to the instruction of the control command unit 6, and a report can be created by the output device 8. At this time, a calibration curve can be created. Thereby, the concentration of the unknown sample is calculated.

 FIG. 2 is a flowchart showing a conventional measuring method.

Reference numeral 50 in FIG. 2 denotes a calibration curve preparation procedure. After specifying calculation methods 51 such as parameters necessary for calculation, standard sample measurement process 52
Measure the retention time for identification. Next, a component table is created in a component table creating step 53 for creating a calibration curve.

As a result, a component table as shown in FIG. 4 is created. At this stage, since the measurement for preparing the calibration curve has not been performed yet, the column 104 of the correction coefficient is blank.

Next, in a calibration curve creation step 54, a standard sample is injected again to measure. As a result, a calibration curve is created, and the calibration curve is
Remember at 57. Reference numeral 55 stores standard data for creating a component table.

Next, the unknown sample is analyzed, and the unknown sample is identified and the concentration is quantitatively analyzed based on the calibration curve stored in 57.

FIG. 3 shows an embodiment of the procedure for automatically preparing a calibration curve according to the present invention.

As is clear from the comparison with the method shown in FIG. 2, the method shown in FIG. 3 simultaneously performs the component identification of the standard sample and the preparation of the calibration curve, so that the standard sample may be injected only once. The present embodiment includes a process 71 for identifying and preparing a calibration curve table, a process 72 for preparing a calibration curve, and a process 76 for measuring an unknown sample after designating parameters 71 necessary for calculation. FIG. 5 shows a component table created by the above embodiment.

Conventionally, an analyst visually confirms the retention time 101 of a standard component measured in a standard sample, identifies the component, and then inputs a standard concentration 103 when the component is mixed. However, according to the present embodiment, as shown in FIG. 5, the correction coefficient is input at the same time as the identification, and the analysis process can be shortened.

Next, a method for automatically identifying components in this example will be described.

FIG. 6 shows an example of the chromatogram of the standard sample. The horizontal axis represents the time axis (for example, minutes) of the chromatogram, and the vertical axis represents the output axis (for example, mV) of the chromatogram. In the chromatogram 202, the identification peak 204 having a peak intensity higher than the preset identification determination level 203 is a benzene: Benzene peak shown in FIG. 102, an identification peak 205 is a toluene: Toluene peak shown in FIG. 102), and The identification peak 206 is the peak of p-xylene shown in FIG. Note that a peak 207 indicates a noise peak.

When measuring a standard sample, specify the calculation method in Fig. 3.
At 71, the identification judgment level 203 of FIG. 6 is set and programmed. When a peak component 204 exceeding the identification judgment level 203 appears, this peak is identified as the first peak specified in FIG. 72, and its retention time is registered as the retention time of Benzene. Do the same for Tolu
Register as ene and p-Xylene.

In addition, since the component 207 in FIG. 6 is a small peak that does not reach the identification determination level of 203, it is programmed to be excluded from the identification calculation.

 The above procedure is shown in a flowchart in FIG.

In a parameter setting step 301, an identification determination level and the like are set in advance. In step 302, a large frame of the component table is created. That is, the component name, the peak detection order (generally the retention time is earlier) and the standard concentration of each component are set. In step 303, a standard sample in which standard components are mixed is prepared according to step 302 described above. In step 304, measurement is started using the standard sample prepared above.
In step 305, the size (height) of the separated and detected peak is compared with the identification determination level. If the peak is larger, the peak is identified as the identification 1 peak (here, the peak exceeding the identification determination level for the first time) ), And the retention time is registered as the first component preset in the component table by 306. Incidentally, a peak not exceeding the identification determination level in step 306 (FIG. 6, 207)
If they are programmed to be ignored, they will not be registered in the component table.

In step 307, check whether the detection of all peaks of the standard sample has been completed. If not completed, continue the analysis. If not completed, in step 308, detect the calibration curve for each component and calculate the correction coefficient. And output to the component table.

According to the present embodiment, since the standard sample can be injected up to the calibration curve at one time, the analysis time can be reduced. Also,
The analysis operation can be easily automated. Note that, instead of setting the identification determination level 203 in FIG. 6, the determination can be made using the absolute value of the peak height or the absolute value of the peak area.

FIG. 8 shows an example of a calibration curve and a component table created by the output device of the analyzer according to the present invention.

[Effects of the Invention] According to the present invention, identification and measurement of a calibration curve can be performed by a single injection of a standard sample, so that analysis efficiency can be improved.

Further, by setting the identification determination level, the analysis operation can be simplified and the reliability of the analysis can be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a flowchart of a conventional quantitative calculation method, FIG. 3 is a flowchart of a quantitative calculation method of the present invention, and FIG. FIG. 5 is a block diagram of the component table of the present invention, FIG. 6 is a chromatogram of the present invention, FIG. 7 is a flow chart of the analysis of the present invention,
FIG. 8 is an analysis chart of a standard sample by the analyzer of the present invention. 1 ... Control command storage, 2 ... Signal data storage, 3 ...
... Parameter storage unit, 4 ... Central processing unit, 5 ... Peripheral device connection unit, 6 ... Control command unit, 7 ... Identification judgment level setting unit, 8 ... Output unit, 9 ... A / D converter , 10 ... Identification control function, 11 ... Identification judgment level storage, 12 ... Identified component name input device, 50 ... Conventional calibration curve making procedure, 51 ... Calculation parameter designation, 52 ... Standard sample measurement, 53 ... Create component table, 54 ... Create calibration curve, 71 ... Specify calculation parameters, 72 ... Identify, create calibration curve creation table, 73
…… Create a calibration curve, 101 …… Retention time, 102 ……
Component name, 103: standard density, 104: correction coefficient, 202:
Chromatogram, 203: Identification judgment level, 204: Identification peak 1, 205 ... Identification peak 2, 206 ... Identification peak 3, 207 ... Non-identification peak, 301: Calculation parameter setting, 302: Component table Preparation process, 303: Standard sample preparation process, 304: Standard sample measurement process, 305: Identification peak determination process, 306: Identification peak retention time, 308: Creation of registered calibration curve, 311: Calibration curve , 31
2 Retention time, 313 Correction coefficient.

Claims (2)

(57) [Claims] In a method for quantitative analysis of a sample in which at least a component to be identified is specified by chromatography, a predetermined amount of a standard sample containing a known amount of the identified component is injected only once into an analysis column, Simultaneously measuring the retention time of the identified component of the standard sample and its peak intensity, and for a chromatogram peak having a higher peak intensity than a predetermined judgment level value, determining the component identification and its calibration curve at once. Characteristic quantitative analysis method by chromatograph. 2. Injecting means for injecting an analytical column sample, A / D converting means for converting an analog signal of a chromatograph from the column into a digital signal, and a command for a control command storing means and a control command means for converting the digital signal into a digital signal. A chromatographic quantitative analysis device having a central processing means for converting the data into a predetermined format set by the above, and a signal data storage means for storing the data, wherein the control command storage means is for preparing a calibration curve for quantification. A table, comprising a component identification determination level setting means, wherein the central processing means, only one injection of a standard sample containing a known amount of the identified component from the injection means, the retention time of the identified component and its A chromatographic quantitative analyzer characterized by having a function of measuring and calculating peak intensity to identify the component and calculate a calibration curve. Apparatus.