US 10,928,367 B2Granted

Peak extraction method and program

AssigneeShimadzu Corporation

InventorHiroaki Kozawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

A peak extraction method for extracting a true peak from a measured waveform, including acquiring a second derivative waveform; extracting a provisional peak on the basis of a maximum value and/or a minimum value of the second derivative waveform; determining the peak width of the provisional peak on the basis of a model peak function; computing, on the basis of the model peak function, a theoretical value for the height of the provisional peak using two points corresponding to the two ends of the peak width; computing, based on the second derivative waveform, an index value for a variation in the noise on the measured waveform; and computing an S/N ratio, which is a ratio of the peak height theoretical value and the index value, and extracting the provisional peak that is equal to or greater than a preset value as the true peak.

Claims6

Dependent claims

A peak extraction method for extracting a true peak from a measured waveform acquired of a component included in a sample using chromatography to identify the component, comprising:

acquiring the measured waveform of the component included in the sample by a chromatograph apparatus;
executing by a processor or a central processing unit (CPU):
a) a second derivative waveform acquisition step for acquiring a second derivative waveform by finding a second derivative of the measured waveform of the component;
b) a provisional peak extraction step for extracting a peak of said measured waveform of the component on the basis of a maximum value and/or a minimum value of said second derivative waveform, and treating said extracted peak as a provisional peak;
c) a peak width determination step for determining a peak width of said provisional peak on the basis of a preset model peak function theoretical equation for said true peak;
d) a peak height theoretical value computation step for computing, on the basis of said preset model peak function theoretical equation, a theoretical value for a height of said provisional peak using two points on either said measured waveform or said second derivative waveform corresponding to two ends of said peak width;
e) a noise index value computation step for computing, based on said second derivative waveform, a noise index value for a variation in a noise of said measured waveform of the component;
f) a peak extraction step for computing an S/N ratio, which is a ratio of said provisional peak height theoretical value and said noise index value, and extracting the provisional peak, for which a value of the S/N ratio is equal to or greater than a preset value, as the true peak;
g) a display step for displaying the extracted true peak of the measured waveform of the component;
and
h) an identification step for identifying the component based on the extracted true peak that is displayed.

8 more elements

A non-transitory computer-readable medium including a peak extraction program for extracting a true peak from a measured waveform of a component included in a sample acquired by a chromatogram apparatus to be executed by a processor to identify the component, the peak extraction program causing the processor, which is capable of accessing a storage that stores a model peak function information including a model peak function theoretical equation set for said true peak, and an S/N threshold information related to an S/N ratio, to execute a method of:

a) a second derivative waveform acquisition step for acquiring a second derivative waveform by finding a second derivative of the measured waveform of the component;
b) a provisional peak extraction step for extracting a peak of said measured waveform of the component on the basis of a maximum value and/or a minimum value of said second derivative waveform, and setting said extracted peak as a provisional peak;
c) a peak width determination step for determining a peak width of said provisional peak on the basis of said model peak function theoretical equation;
d) a peak height theoretical value computation step for computing, on the basis of said model peak function theoretical equation, a theoretical value for a height of said provisional peak using two points on either the measured waveform or the second derivative waveform corresponding to two ends of said peak width;
e) a noise index value computation step for computing, based on said second derivative waveform, a noise index value for a variation in a noise of said measured waveform of the component;
f) a peak extraction step for computing the S/N ratio, which is a ratio of said provisional peak height theoretical value and said noise index value, and extracting the provisional peak, for which a value of the S/N ratio is equal to or greater than said S/N threshold, as the true peak;
g) a display step for displaying the true peak of the measured waveform of the component;
and
h) an identification step for identifying the component based on the true peak that is displayed.

6 more elements

Dependencies are inferred from the claim text.