JPH07120451A - Chromatograph having automatic column evaluation - Google Patents

Abstract

PURPOSE:To automate the judgement of column deterioration. CONSTITUTION:This chromatograph is equipped with a dividing and identifying section 22 for obtaining a chromatogram from data saved in a detector output memory section 20, extracting a peak therefrom, and identifying and determining the component thereof by using a calibration curve. Also, the chromatograph is equipped with a separative power calculation and judgement section 24 for calculating separative power by using two prescribed data peaks for the calculation after the identification and determination of the component, and making judgement as to whether a column is normal or deteriorated via the comparison of the calculation result with a reference value S0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromatograph such as a liquid chromatograph and a gas chromatograph.

[0002]

2. Description of the Related Art In a liquid chromatograph or a gas chromatograph, a separation column is used to separate each component of a sample. The separation performance of the separation column deteriorates as the analysis is repeated. The extent to which the separation performance deteriorates and the column should be replaced is determined empirically by the user from the shape of the obtained chromatogram.

[0003]

The method of visually determining the deterioration of the column from the chromatogram is troublesome because the operator has to make the determination each time by looking at the chromatogram. In addition, the judgment results will differ depending on experience and individual differences. Therefore, the present invention aims to eliminate visual annoyance and individual difference by providing a function of automatically determining whether a column is deteriorated from the obtained chromatograph in a chromatographic data processing device. To do.

[0004]

According to the present invention, a chromatogram is assigned to a data processing device for identifying and quantifying a sample component by obtaining a chromatogram from the output of a detector.
The separability is calculated from two peaks, and the calculation result is compared with the reference value.If the reference value is satisfied, the column is determined to be normal, and if the reference value is not satisfied, the column is degraded. A separability calculation / determination unit for determination is provided.

[0005]

The data processor temporarily stores the detector output as data. The data of the two peaks designated for calculating the resolution among the analytes were extracted,
The resolution between the two peaks is calculated and compared to a reference value. The sample for calculating the resolution was either a control sample containing the components of the two peaks for calculating the resolution, or a standard sample for creating the calibration curve, which contained the two components for calculating the resolution. It is a thing.

In the analysis of amino acids, threonine and serine can be used as components suitable for calculating the resolution. Other two component peaks that appear as other suitable adjacent peaks are also available.

The resolution calculation is shown below. First, the degree of separation α is calculated. The degree of separation α is obtained as α = K ₂ / K ₁ (1). Where K ₁ = (R ₁ −R ₀ ) / R ₀ ,
_{K 2 = (R 2 -R 0} ) is / R _0. R ₀ is the retention time of the solute passing through the column, which can be calculated from the column size and analytical conditions. R ₁ is the retention time of the designated component, and R ₂ is the retention time of the designated component that elutes next to the designated component.

Next, the theoretical plate number N is calculated. Number of theoretical plates N
Is calculated as N = 6.28 (R ₁ · T ₁ / A ₁ ) ² (2). Here, T ₁ is the peak height of the first eluting component of the two designated components, and A ₁ is the peak area of the designated component.

Next, the separability S is calculated. The resolution S is given by the following equation.

[0010]

[Equation 1]

If the resolving power S is equal to or greater than the reference value S ₀ , it is determined that the column is normal, and if the resolving power S is less than S ₀ , it is determined that the column is deteriorated. The reference value S ₀ is, for example, 1.
Set it to 0.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration diagram in which the present invention is applied to a liquid chromatograph. A sample injection part 8, a separation column 10, and a detector 12 for detecting an elution component from the separation column 10 are arranged in this order in the flow path 6 through which the eluent 4 is fed by the liquid feed pump 2. The effluent from the is discharged to the drain. A data processing device 14 is provided to capture the output signal of the detector 12 to obtain a chromatogram and to identify and quantify the sample components.
The data processing device 14 also has a function for automatically evaluating deterioration of the column in the present invention.

The function of the data processing device 14 is shown in FIG.
The output signal from the detector 12 is converted into a digital signal and taken into the data processing device 14. A detector output storage 20 is provided to store the captured data. The chromatogram is obtained from the data stored in the detector output storage unit 20, peaks are extracted from the chromatogram, the components are identified, and the fractionation / identification unit 22 is also used for quantification using the calibration curve. Is provided. After the identification and quantification, the resolution is calculated using the data of the two peaks for the calculation of the resolution specified in advance, and the column is normal by comparing the calculated resolution with the reference value S _0. A separability calculation / determination unit 24 is provided to determine whether the deterioration has occurred. A warning display unit 26 is also provided for displaying a warning when it is determined that the column is deteriorated. The detector output storage unit 20 is realized by RAM, and the fractionation / identification unit 22 and the separability calculation / determination unit 24 are realized by CPU, ROM, and RAM. The warning display unit 26 is realized by using a part of the display.

Next, the operation of this embodiment will be described with reference to FIG. The detector output is stored in the detector output storage unit 20,
After storing all the data, the fractionation / identification unit 22 fractionates the chromatogram for each peak to identify and quantify each peak.

When the measured sample is a control sample for calculating the resolution, or a standard sample containing two components used for calculating the resolution, the resolution calculation
The determination unit 24 calculates the separability S according to the equation (3). If the calculated resolution S is equal to or greater than the reference value S ₀ , the column is determined to be normal, and if the calculated resolution S is less than the reference value S ₀ , the column is deteriorated. The warning shown is displayed on the warning display unit 26.

If the sample is neither a control sample nor a standard sample containing a component for calculating the resolution, the identification and quantification results of each peak of the chromatogram by the fractionation / identification unit 22 are output. To be done.

Although the embodiment shows an example applied to a liquid chromatograph, it can be applied to a gas chromatograph as well. When a warning is displayed when it is determined that the column is degraded due to the resolution S, the resolution value indicating the degree of column degradation, the date and time of the determination, the name of the analytical sample used for the determination, etc. are recorded. You may keep it.

[0018]

According to the present invention, the separability is calculated from the peaks of the two designated components of the obtained chromatogram, and it is automatically judged whether the column is normal or deteriorated based on the calculated separability. By doing so, it is possible to automatically inform the user whether or not the column is normal during the daily analytical operation, and the conventional troublesomeness of the operator having to judge by looking at the chromatogram is eliminated. Moreover, since the determination is made based on the numerical value of the separability, the determination result is objective and there is no individual difference.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a liquid chromatograph showing an example.

FIG. 2 is a block diagram mainly showing a data processing device in the embodiment.

FIG. 3 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

 10 Separation column 12 Detector 14 Data processing device 20 Detector output storage unit 22 Fractionation / identification unit 24 Separation power calculation / determination unit 26 Warning display unit

Claims (1)

[Claims] 1. A chromatograph comprising at least a separation column, a detector for detecting a sample component eluted from the separation column, and a data processing device for identifying and quantifying the sample component by obtaining a chromatogram from the output of the detector. In the data processing device,
The separability is calculated from two peaks, and the calculation result is compared with the reference value.If the reference value is satisfied, the column is determined to be normal, and if the reference value is not satisfied, the column is degraded. A chromatograph characterized by comprising a resolution calculating / determining unit for determination.