CN107664624A - The other near-infrared spectral analytical method of mammalian is differentiated based on gas - Google Patents

Abstract

The invention discloses a near-infrared spectrum analysis method for discriminating the gender of mammals based on gas. Firstly, gas samples of male animals and female animals of the same species of mammals are collected, and the near-infrared spectra of the obtained gas samples are collected under certain measurement conditions. The obtained spectrum No preprocessing or chemometric preprocessing is performed, the modeling spectral range is selected from the obtained spectral data, and after dimensionality reduction is performed on the data of the selected spectral range, a chemometric method is used to establish and verify the gender discrimination of this species of mammal Then take the gas sample of the mammal whose sex is unknown, collect the spectrum according to the same method as above and perform multi-step processing of the spectral data, and finally apply the established model to determine the sex of the mammal. The invention is based on the near-infrared spectrum of the gas and combined with the chemometrics technology to determine the gender of the mammal, and has the advantages of accurate, fast and easy operation of the analysis method, and good compliance of the tested body.

Description

A Near-infrared Spectroscopy Analysis Method Based on Gas to Discriminate the Sex of Mammals

technical field

The invention belongs to the technical field of near-infrared spectrum analysis and relates to a near-infrared spectrum analysis method for discriminating the gender of mammals based on gas.

Background technique

Gender research is one of the important contents of biology. Mammals are the most advanced stage of animal development. In the ecological management of mammals, sex discrimination is a basic task in the analysis of population dynamics. Human beings are the most advanced mammals, and the gender discrimination of the human body is an important content of identification, which is of great significance in the fields of personalized services, medical care, and public safety management. Physical examination is a classic method of human sex discrimination, but it has certain limitations because of the need for special inspection sites and specific inspection personnel.

Contents of the invention

The object of the present invention is to provide a near-infrared spectroscopic analysis method for discriminating the sex of mammals based on gas, which has the advantages of accurate analysis method, convenient use, and good compliance of the tested body.

After research, the present invention provides the following technical solutions:

(1) Collect gas samples of male animals and female animals of the same species of mammals

(2) The resolution and the number of scans of the near-infrared spectrometer are set, and the near-infrared spectra of the gas samples obtained in step ( ¹ ) are collected respectively within the scanning range of 10000 to 4000 cm;

(3) to step (2) gained spectrum, do not carry out pretreatment or carry out chemometrics pretreatment;

(4) select the modeling spectral range in step (3) gained spectral data;

(5) carry out dimensionality reduction to the data of step (4) selected spectral range;

(6) For the data obtained in step (5), adopt the chemometrics method to establish and verify the sex discrimination model of this kind of mammal;

(7) Take the gas sample of the mammal of unknown gender, collect the near-infrared spectrum according to the method described in step (2), carry out the multi-step processing of the spectrum according to the method described in steps (3) to (5), and then apply the step ( 6) The established model is used for sex discrimination of mammals.

When the gender of a mammal is determined, the gas of the mammal is used as a sample, which has the advantages of non-destructive and repeatable sample collection.

Preferably, in step (2), the resolution of the near-infrared spectrometer is set to 2cm ^-1 , 4cm ^-1 , 8cm ^-1 or 16cm ^-1 , and the number of scans is set to 32, 64 or 128 times.

Preferably, in step (2), the near-infrared spectrum is near-infrared diffuse reflection spectrum or near-infrared transmission spectrum.

Preferably, in step (3), the chemometric preprocessing method is one or more combinations of multivariate signal correction, standard canonical transformation, derivative and smoothing.

In step (4), the modeling spectral range is one or more segments in 10000-4000cm ^-1 , which can be automatically screened or manually screened by the modeling software, or can be selected according to the analyte on the basis of the automatic screening of the modeling software. The near-infrared characteristic absorption is further artificially optimized.

Preferably, in step (5), principal component analysis is used to reduce the dimensionality of the data in the spectral range selected in step (4).

Preferably, the selection basis of the modeling principal component is that the cumulative variance contribution rate is greater than 85% and the positive judgment rate of the calibration set and the verification set of the discriminant model built in step (6) are both greater than 95%.

Preferably, in step (6), the chemometric modeling method is a discriminant analysis method.

Preferably, in step (6), the performance of the established discriminant model is evaluated by the correct judgment rate of the calibration set and the correct judgment rate of the verification set.

Preferably, the mammal is a human.

Preferably, the near-infrared spectral analysis method for discriminating the gender of a human body based on gas comprises the following steps:

(1) Using ethanol with a volume percentage concentration of 50% as a solvent to collect gas samples exhaled from male mouths and female mouths;

(2) Set the resolution of the near-infrared spectrometer to 8cm ^-1 and the number of scans to 64 times, and collect the near-infrared transmission spectra of the gas samples obtained in step (1) within the scanning range of 10000 to 4000cm ^-1 ;

(3) Two methods of second derivative and Norris smoothing are used to preprocess the spectrum obtained in step (2);

(4) Select 9881～4119cm ^-1 as the modeling spectral range in the spectral data obtained in step (3);

(5) Dimensionality reduction is carried out to the data in the selected spectral range of step (4) by principal component analysis;

(6) to step (5) gained data, be 6 with modeling principal component number, adopt discriminant analysis method to set up and verify the gender discrimination model of human body, judge the performance of model with correction set correct judgment rate and verification set correct judgment rate;

(7) Take a gas sample from a human body of unknown gender, collect the near-infrared transmission spectrum according to the method described in step (2), perform multi-step processing of the spectrum according to the method described in steps (3) to (5), and then apply step (6) The built model is used for gender discrimination of human body.

The beneficial effect of the present invention is that: the present invention is based on the near-infrared spectrum of the gas, combined with the chemometrics technology, to distinguish the gender of the mammal, and has the advantages of accurate, fast and easy operation of the analysis method, and the compliance of the tested body is good.

Description of drawings

Figure 1 is the near-infrared transmission original spectrum of 6 human gas samples.

Fig. 2 is the discriminant diagram of the human body gender discriminant model built in the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1 Determining the gender of a human body based on gas

1. Collection and processing of gas samples

A total of 18 gas samples were collected from 6 volunteer subjects, 2 males and 4 females, for 3 consecutive days. When collecting gas samples, the subjects used an airway tube to blow air into a 25ml volumetric flask filled with 50% ethanol by volume for 5 minutes, then immediately plugged the bottle stopper, numbered them one by one and recorded their gender information.

2. Acquisition of near-infrared transmission spectra

Instrument: Antaris II Fourier transform near-infrared spectrometer (Thermo Company, USA), equipped with an integrating sphere accessory, and the signal acquisition software is Result 3.0.

Spectral measurement conditions: the resolution is 8cm ^-1 , the number of scans is 64, and the scan range is 10000-4000cm ^-1 .

Spectral measurement method: use a 5ml sterile syringe to suck out the ethanol solution in which the gas sample is dissolved in the volumetric flask, and inject it into the liquid sample tube (6×50mm) equipped with the instrument. The sample injection volume is about 2/3 of the volume of the sample tube. Put the tube into the liquid sample holder, and measure the near-infrared transmission spectrum of the sample under the above-mentioned spectral measurement conditions. Each sample is measured once, and the same measurement conditions are used to scan and subtract the background before each sample measurement.

The 18 near-infrared transmission raw spectra of 18 human gas samples are shown in Figure 1.

3. Spectral Preprocessing

TQ Analyst 8.0 software was used to preprocess the collected near-infrared transmission raw spectra with second derivative and Norris smoothing.

4. Selection of modeling spectral range

For the preprocessed spectral data, the modeling spectral range automatically selected by TQ Analyst 8.0 software is 9881～4119cm ^-1 .

5. Dimensionality reduction of spectral data

Using TQ Analyst 8.0 software, principal component analysis was used to reduce the dimensionality of the preprocessed spectral data within the selected modeling spectral range of 9881-4119 cm ^-1 . When the number of selected modeling principal components was 6, the cumulative variance contribution The rate is 100.0%, and the positive rate of the calibration set and the verification set of the built model are both 100.0%.

6. Establishment and verification of discriminant model

The collected gas samples of 1 male and 3 female volunteer subjects were used as the calibration set samples, and the gas samples of the remaining 1 male and 1 female volunteer subjects were used as the verification set samples. Using the above calibration set samples and verification set samples respectively, with a principal component number of 6, the discriminant analysis method was used to establish and verify the gender discrimination model of the human body. The results are shown in Figure 2. The correct judgment rate of the built discriminant model is 100.0% in the calibration set and 100.0% in the verification set, which shows that the built model has good discriminative performance and can accurately determine the sex of human body using gas samples.

7. Analysis of human gas samples of unknown gender

Take a human gas sample of unknown gender, process the sample according to the same method as above, collect the near-infrared transmission spectrum of the sample, and perform multi-step processing on the spectrum, and then apply the built model to distinguish the human body gender of the gas sample, and the result correctly shows that it is female.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art should understand that it can be described in terms of form and Various changes may be made in its details without departing from the scope of the invention as defined in the appended claims.

Claims (9)

1. The near-infrared spectral analysis method based on gas discrimination of mammal sex, is characterized in that, comprises the following steps: (1) Collect gas samples from male animals and female animals of the same species of mammals; (2) The resolution and the number of scans of the near-infrared spectrometer are set, and the near-infrared spectra of the gas samples obtained in step ( ¹ ) are collected respectively within the scanning range of 10000 to 4000 cm; (3) to step (2) gained spectrum, do not carry out pretreatment or carry out chemometrics pretreatment; (4) select the modeling spectral range in step (3) gained spectral data; (5) carry out dimensionality reduction to the data of step (4) selected spectral range; (6) For the data obtained in step (5), adopt the chemometrics method to establish and verify the sex discrimination model of this kind of mammal; (7) Take the gas sample of the mammal of unknown gender, collect the near-infrared spectrum according to the method described in step (2), carry out the multi-step processing of the spectrum according to the method described in steps (3) to (5), and then apply the step ( 6) The established model is used for sex discrimination of mammals. 2. The near-infrared spectral analysis method based on gas discrimination of mammal sex according to claim 1, characterized in that: in the step (2), the resolution of the near-infrared spectrometer is set to 2cm ^-1 , 4cm ^-1 , 8cm ^-1 or 16cm ^-1 , the number of scans is set to 32, 64 or 128 times. 3. the near-infrared spectrum analysis method based on gas discrimination mammal sex according to claim 1, is characterized in that: in described step (3), the method for chemometrics preprocessing is multiple signal correction, standard regular transformation, One or more combinations of derivatives and smoothing. 4. the near-infrared spectral analysis method based on gas discrimination mammal gender according to claim 4, is characterized in that: in described step (5), adopt principal component analysis method to the data of the selected spectral range of step (4) Perform dimensionality reduction. 5. the near-infrared spectrum analysis method based on gas discrimination mammalian sex according to claim 4, it is characterized in that: the selection basis of modeling principal component score is greater than 85% and step (6) builds for its accumulative variance contribution rate The positive judgment rate of the calibration set and the verification set of the discriminant model are both greater than 95%. 6. The near-infrared spectral analysis method for discriminating the sex of mammals based on gas according to claim 1, characterized in that: in the step (6), the chemometrics modeling method is a discriminant analysis method. 7. the near-infrared spectrum analysis method based on gas discrimination mammal sex according to claim 1, is characterized in that: in described step (6), the performance of built discriminant model is corrected with correction set positive rate and verification set. Judgment rate is evaluated. 8. The near-infrared spectroscopic analysis method for discriminating the sex of a mammal based on gas according to any one of claims 1 to 7, wherein the mammal is a human being, and the gas is exhaled from the mouth. 9. the near-infrared spectrum analysis method based on gas discrimination mammal sex according to claim 8, is characterized in that, comprises the following steps: (1) Using ethanol with a volume percentage concentration of 50% as a solvent to collect gas samples exhaled from male mouths and female mouths; (2) Set the resolution of the near-infrared spectrometer to 8cm ^-1 and the number of scans to 64 times, and collect the near-infrared transmission spectra of the gas samples obtained in step (1) within the scanning range of 10000 to 4000cm ^-1 ; (3) Two methods of second derivative and Norris smoothing are used to preprocess the spectrum obtained in step (2); (4) Select 9881～4119cm ^-1 as the modeling spectral range in the spectral data obtained in step (3); (5) Dimensionality reduction is carried out to the data in the selected spectral range of step (4) by principal component analysis; (6) to step (5) gained data, be 6 with modeling principal component number, adopt discriminant analysis method to set up and verify the gender discrimination model of human body, judge the performance of model with correction set correct judgment rate and verification set correct judgment rate; (7) Take a gas sample from a human body of unknown gender, collect the near-infrared transmission spectrum according to the method described in step (2), perform multi-step processing of the spectrum according to the method described in steps (3) to (5), and then apply step (6) The built model is used for gender discrimination of human body.