JPS63151851A - Data processor for chromatograph - Google Patents

Abstract

PURPOSE:To set the initial value of a function parameter efficiently, by estimating an initial parameter by computation from two chromatograms different in detection wavelength when overlap peaks of the chromatograms are analyzed by non-linear least square method. CONSTITUTION:A spectral data or the like from a liquid chromatogram is converted 1 into digital from analog to be inputted into a CPU 5. Then, it is converted into a matrix type data with a control command device 6 to be stored into a data storage 3. Two chromatograms are called up with an overlap peak analyzer 9, one chromatogram is multiplied by a scale factor to cancel one of overlap peaks and a difference is determined between the results and the other chromatogram to estimate an initial value (peak position and peak range) of a non-linear parameter. The initial value is applied to a non-linear least square fitting device 10, which performs a fitting of peaks and produces an output 8. This enables the setting of the initial value satisfactorily thereby allowing efficient finding of an solution with a higher convergency of calculation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to chromatographic data processing, and particularly to a method for decomposing and quantifying overlapping peaks.

[Conventional technology]

In conventional devices, overlapping peaks are resolved by vertical division or skimming division processing. On the other hand, even when a certain function is assumed and the optimal parameters are determined by the nonlinear least squares method, the initial values of the parameters are set using the single peak itself.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not give much consideration to good initial value settings when optimizing nonlinear parameters, resulting in problems such as not being able to obtain optimal parameters (no solution is reached), and requiring a large amount of calculation time. there were.

An object of the present invention is to efficiently set initial values of function parameters for overlapping peak decomposition.

[Means for solving problems]

In order to achieve the above objective, a chromatogram with two or more wavelengths is required. Multiply one chromatogram by a scale factor so as to cancel one of the overlapping peaks, and take the difference from the other chromatogram. Due to this,
From the remaining peaks, it is easy to set good initial values for the parameters of the function that fits this peak.

[Effect] By being able to set good initial values, divergence in calculations using the nonlinear least squares method is prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Analog signal from liquid chromatograph (chromatogram,
The spectrum) is converted into a digital signal via the A/D converter 1 and enters the central processor 5 via the peripheral device connector 7. Thereafter, the control command unit 6 converts the data into data in a predetermined matrix format according to a command from the control command storage unit 2, and stores the data in the signal data storage unit 3. Two chromatograms are called from the stored data, and the overlapped Bieghe decomposer 9 calculates the initial value (peak position) of the function that simulates each peak from the difference chromatogram.

Complete fitting of the zero-overlap peaks obtained (peak width) and stored in the parameter storage 4 is performed by a nonlinear least squares fitting device 10, and the calculation result is outputted via the output device 8.

Figure 2 shows an example of decomposition of two overlapping beaks, (a) and (b)
is a chromatogram obtained using the detection wavelength Jinba. (C) is a difference chromatogram obtained by multiplying by a scale factor α to cancel the second peak. From this differential chromatography, the position (ti't) and peak width (6z') of peak 1 can be determined. (d) is a difference chromatogram obtained by canceling peak 1, and from this, the second peak t nOs and 620 are obtained. The obtained values (610°6°2. tR1', tR2°) are used as initial values, and A50 and Ax.

Assuming the value of , complete peak decomposition is performed once again using the nonlinear least squares method to obtain (a). In the case of three overlapping peaks, by adjusting the scaling coefficient to cancel the middle peak and obtaining a difference chromatogram, the peaks at both ends of the peak are
aO) can be obtained.

(tx', 62') should be an estimated value and finally determined by the nonlinear least squares method.

The calculation process will be explained below using the flowchart shown in FIG.

11 analysis start line 1 is entered according to the command from the control command unit 6,
Through the A/D analyzer l, a chromatogram and spectrum simultaneous acquisition process a12 is performed, and a storage process 13 to the data storage unit 3 is executed, and one analysis is completed in step 14. After that, two chromatograms with different detection wavelengths are called up using the staff 15, a scale factor α is introduced into one chromatogram (16), and a difference chromatogram is taken between it and the other chromatogram (17). ), 18 to determine whether the chromatographic peak is isolated.

16-18 staves are performed for α, α' until a completely isolated peak is obtained.

19, the peak position (tR'z) as the initial value of the Fitting function is determined from the obtained isolated peak.

tR'z) and peak width (6t', 6z').

Initial value for peak height (AX', Ax') at 20
is introduced, and each parameter (6, tu.

After obtaining the optimum value of A), in step 22, each peak is quantified based on the peak height or peak area value, and in step 23, the calculation results are displayed.

〔Effect of the invention〕

According to the present invention, it is possible to set the initial value well when searching for overlapping chromatographic peaks using the nonlinear least squares method, so it is possible to speed up the convergence of calculations and efficiently obtain a solution.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the present invention, FIG. 2 is a diagram showing an example of decomposition of a two-component peak, and FIG. 3 is a flow chart of the process of the present invention.

Claims (1)

[Claims] 1. A/D converter (chromatogram and spectrum),
In a chromatographic data processing device consisting of a data storage, control command unit, control command storage, data processing parameter storage, peripheral device connector, output device, etc., overlapping peaks are decomposed using Gaussian or exponential methods. When performing the nonlinear least squares method using a modified Gaussian (EMG) function, the initial value of the nonlinear parameter is calculated by multiplying one of the two chromatograms with different detection wavelengths by a scaling coefficient, and calculating the difference from the other chromatogram. A chromatographic data processing device characterized by estimating initial parameters of each peak from a chromatogram.