CN104730042A - Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy - Google Patents
Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy Download PDFInfo
- Publication number
- CN104730042A CN104730042A CN201510101932.XA CN201510101932A CN104730042A CN 104730042 A CN104730042 A CN 104730042A CN 201510101932 A CN201510101932 A CN 201510101932A CN 104730042 A CN104730042 A CN 104730042A
- Authority
- CN
- China
- Prior art keywords
- genetic algorithm
- line
- temperature
- internal standard
- induced breakdown
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention discloses a method for improving free calibration analysis precision by combining a genetic algorithm with a laser induced breakdown spectroscopy (LIBS). The method comprises the following steps: selecting an analysis line and an internal standard line through the LIBS; calibrating the intensity of a characteristic spectrum line of each element by the internal standard line ignoring self absorption so as to reduce the influences caused by self-absorption effects; secondly, carrying out plasma optimizing computation by only using one standard sample in a certain range by applying the genetic algorithm; and determining an optimal plasma temperature under the measurement environment, and carrying out quantitative analysis by taking the temperature as an estimated value of the plasma temperature of other unknown samples. The internal standard line is applied and the estimation of the plasma temperature is accurate so that the method combining an internal standard with an external standard can be used for extremely improving the accuracy of free calibration when being compared with traditional free calibration.
Description
Technical field
The present invention relates to a kind of genetic algorithm improves free calibration analysis precision method in conjunction with Laser-induced Breakdown Spectroscopy, belong to field of spectral analysis technology.
Background technology
Laser-induced Breakdown Spectroscopy (laser-induced breakdown spectroscopy, LIBS) be a kind of emerging atomic emission spectrum technology, LIBS technology with it fast, be successfully applied to the quantitative test of metal and alloy, the artwork, historical relic legacy, environmental sample, geological sample, biomedical samples and nuclear material without the need to advantages such as complex sample pre-treatment and Simultaneous multi element analysis.
Calibration curve method is the common method in quantitative test, by to a series of have concentration (or) standard specimen of concentration gradients measures, set up the typical curve model between spectrum integral intensity (or integral area) corresponding to component to be measured and content, utilize this model can predict the component content of unknown sample.In spectral analysis field, common calibration curve method, if internal standard method, external standard method etc. are the most basic quantitative analysis methods, especially internal standard method can improve LIBS accuracy of quantitative analysis to a certain extent, is thus used widely.But external standard method and internal standard method all need a series of standard specimens of Matrix Match, and standard specimen costly; In addition, when measurement environment is unstable, when sample composition kind is complicated, the as easy as rolling off a log interference being subject to matrix effect of the typical curve of foundation.
Free scaling method (Calibration-free, CF) is applicable to the important quantitative analysis tech means of another kind that LIBS analyzes.The maximum feature of the method does not need to set up calibration curve by standard specimen but carrys out the relation between descriptive element content and spectral intensity by plasma emission mechanism founding mathematical models, and it can avoid the impact of matrix effect to a certain extent.One step of freely calibrating most critical in computation process is exactly solving of plasma temperature, normally by setting up Boltzmann planimetric map to calculate, Boltzmann curve is parallel in theory, that is, in plasma, the temperature of each element should be consistent, but because each elemental characteristic spectral line is subject to the impact of self absorption effect in various degree in actual conditions, the actual strength of spectral line can not be objectively responded, thus badly influence the quantitative test performance of free calibrating method.
Genetic algorithm (Genetic Algorithm, GA) is a kind of didactic global optimizing method, and the material genetic evolution thought that it uses for reference occurring in nature proposes.The basic thought of genetic algorithm uses for reference theory of biological evolution, optimization problem is modeled as the evolutionary process of living species, by copying, intersecting, the effect such as variation produces species of future generation, then by relatively eliminating the low individuality of fitness, retain the individuality that fitness is high, along with the propelling of evolutionary process, the individuality that in population, fitness is high gets more and more, and the individuality that fitness value of evolving out is the most at last the highest is optimum solution.
Summary of the invention
The object of this invention is to provide a kind of genetic algorithm improves free calibration analysis precision method in conjunction with Laser-induced Breakdown Spectroscopy, plasma temperature more accurately can be obtained, improve the quantitative test performance of freely calibrating.
Implementation procedure of the present invention is as follows:
Genetic algorithm improves a method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy, comprises the following steps:
(1) Laser-induced Breakdown Spectroscopy system is utilized to carry out spectrum data gathering respectively to aluminium bronze sample;
(2) wavelet transformation is carried out to the spectrogram obtained and filter the rear selection analysis line of process of making an uproar and internal standard line;
(3) in free scaling theory formula, introduce a self absorption factor and carry out calibration spectrum intensity;
(4) from standard specimen, best plasma temperature is sought by genetic algorithm;
(5) obtain and utilize internal standard line after plasma temperature by the temperature correction of unknown sample to this temperature, calculate the content of unknown sample.
In above-mentioned steps (2), each particle selection one of each sample is supposed to ignore the internal standard line of self-absorption.
In above-mentioned steps (3), the internal standard line of each analytical line with selection is done than the calibration intensity that can estimate analytical line.
In above-mentioned steps (4), obtain Boltzmann figure by the spectral intensity after calibration, and then obtain series of temperature, between minimum and maximum temperature, obtain best plasma temperature by genetic algorithm.
Advantage of the present invention and good effect: genetic algorithm and LIBS spectrum are combined the analysis precision improving and freely calibrate by the present invention, the present invention refer to a kind of based on the free scaling method (Internal reference-external standard for iteration correction, IRESIC) of interior mark-external standard from iteration correction.Introduce internal standard line and can reduce self absorption effect, the spectral intensity of calibration spectral line.At this moment genetic algorithm is used in a standard specimen and seeks best plasma temperature, can overcome the Different Effects of self-absorption to different particle, this be also first genetic algorithm is used freely calibrate in carry out accounting temperature.Calculated the content of unknown sample by the optimum temperature obtained, and then compare with traditional freely calibrating, the method substantially increases the analysis precision freely calibrated.
Accompanying drawing explanation
Fig. 1 is the operational flowchart of IRESIC;
Fig. 2 is the Boltzmann figure of standard model before and after IRESIC initialization corrects;
Fig. 3 is genetic algorithm iteration result;
Fig. 4 is the Boltzmann figure of unknown sample before and after IRESIC corrects.
Embodiment
Below for 1 standard specimen and 1 unknown sample, further illustrate operating process of the present invention with example by reference to the accompanying drawings, but the present invention is not limited thereto example.
Embodiment 1
Genetic algorithm improves a method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy, comprises the following steps:
(1) Laser-induced Breakdown Spectroscopy system is utilized to carry out spectrum data gathering respectively to aluminium bronze sample;
(2) wavelet transformation is carried out to the spectrogram obtained and filter the rear selection analysis line of process of making an uproar, then from analytical line, the internal standard line ignoring self-absorption is assumed to be to often kind of particle selection one;
(3) in free scaling theory formula, introduce a self absorption factor and carry out calibration spectrum intensity;
(4) calculate the temperature of each particle based on Boltzmann figure, find out maximum temperature and minimum temperature, in minimum and maximum temperature range, use genetic algorithm determine best plasma temperature;
(5) utilize internal standard line by the temperature correction of each for unknown sample particle to optimum temperature, calculate the content of unknown sample based on CF.
After spectra collection, one all to be selected to affect the analytical line of less (excitation level should larger and transition probability is lower) as internal standard line by self-absorption for each particle, as shown in table 1 to the internal standard line selected by often kind of particle.
As shown in Figure 2, this example is the contrast to standard specimen Boltzmann figure before and after IRESIC preliminary corrections.Point before correction in Boltzmann figure is more at random, the linear relationship of the tropic is poor, and after the correction of IRESIC, the linear dependence of various particle is clearly better, point in figure can converge near the tropic substantially, but the slope of each bar tropic is also inconsistent, illustrate that line strength of each particle is subject to the impact difference of self-absorption.
Calculate the temperature that each particle slope of regression line is corresponding, that wherein temperature is the highest is T
mn II=35116K, that temperature is minimum is T
cu I=8313.9K, therefore carries out genetic algorithm optimizing between temperature range 8313.9K-35116K, and Population Size is 7, individual lengths is 14, crossover probability pc=0.5, mutation probability pm=0.2, iterations is 120 times, and represented by Fig. 3 is genetic algorithm optimizing result.As shown in the figure, along with the increase of iterations, minimum relative error is more and more lower, finally tend towards stability, illustrate in the initialization colony evolving beginning, do not find best individuality, and with after operate through selection, good for fitness individuality is remained the individuality simultaneously eliminating difference, pass through interlace operation simultaneously, generate new individuality, if the fitness of new individuality is better, then can remain as " excellent genes ", simultaneously in order to avoid being absorbed in locally optimal solution too early, mutation operation through small probability can carry out " local improving " some individuality, through the iteration that this is generation upon generation of, it will be all the excellent individual that fitness is higher in last colony, then the highest optimized individual of fitness can be selected, the optimal plasma temperature that this genetic algorithm optimizing is finally determined is 12086.68K.
For unknown sample, each element analysis spectrum line first utilizes internal standard line after initial optimization, again correct based on optimal plasma temperature discreet value 12086.68K, the tropic in its Boltzmann figure is corrected near optimum temperature, Fig. 4 illustrates the Boltzmann figure of testing sample before and after IRESIC corrects and contrasts, as we can see from the figure, the Boltzmann figure tropic of each particle is substantially parallel, and temperature corresponding to slope is close to plasma temperature discreet value.The content of each component is calculated finally by CF-LIBS.
The quantitative precision of free scaling method that table 2 shows after IRESIC corrects freely has calibrated significant raising compared to traditional, and this also presents is only that online, on-the-spot real-time analysis provides reliability with the free scaling method of the IRESIC of a standard specimen.
Claims (4)
1. genetic algorithm improves a method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy, it is characterized in that comprising the following steps:
(1) Laser-induced Breakdown Spectroscopy system is utilized to carry out spectrum data gathering respectively to aluminium bronze sample;
(2) wavelet transformation is carried out to the spectrogram obtained and filter the rear selection analysis line of process of making an uproar and internal standard line;
(3) in free scaling theory formula, introduce a self absorption factor and carry out calibration spectrum intensity;
(4) from standard specimen, best plasma temperature is sought by genetic algorithm;
(5) obtain and utilize internal standard line after plasma temperature by the temperature correction of unknown sample to this temperature, calculate the content of unknown sample.
2. improve the method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy according to a kind of genetic algorithm described in claim 1, it is characterized in that: in step (2), each particle selection one of each sample is supposed to ignore the internal standard line of self-absorption.
3. improve the method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy according to a kind of genetic algorithm described in claim 1, it is characterized in that: in step (3), the internal standard line of each analytical line with selection is done than the calibration intensity that can estimate analytical line.
4. improve the method for free calibration analysis precision in conjunction with Laser-induced Breakdown Spectroscopy according to a kind of genetic algorithm described in claim 1, it is characterized in that: in step (4), Boltzmann figure is obtained by the spectral intensity after calibration, and then obtain series of temperature, between minimum and maximum temperature, obtain best plasma temperature by genetic algorithm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510101932.XA CN104730042A (en) | 2015-03-10 | 2015-03-10 | Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510101932.XA CN104730042A (en) | 2015-03-10 | 2015-03-10 | Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104730042A true CN104730042A (en) | 2015-06-24 |
Family
ID=53454138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510101932.XA Pending CN104730042A (en) | 2015-03-10 | 2015-03-10 | Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104730042A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105203526A (en) * | 2015-09-22 | 2015-12-30 | 中国科学院上海技术物理研究所 | Calibration-free remote quantitative laser-induced breakdown spectroscopy analysis method |
| CN106841170A (en) * | 2016-12-05 | 2017-06-13 | 西北大学 | A kind of coal ash category identification method based on wavelet neural network algorithm combination LIBS technologies |
| CN107817239A (en) * | 2016-09-13 | 2018-03-20 | 中国科学院沈阳自动化研究所 | A kind of LIBS spectral correction methods based on plasma position information |
| CN108572177A (en) * | 2018-05-21 | 2018-09-25 | 中北大学 | The online constant temperature detection method of welding arc pollutant based on emission spectrum |
| CN108918474A (en) * | 2018-04-26 | 2018-11-30 | 安徽师范大学 | For reducing the matrix dilution process of laser induced breakdown spectroscopy self absorption effect |
| CN109781711A (en) * | 2019-02-21 | 2019-05-21 | 华中科技大学 | A kind of laser induced breakdown spectroscopy quantitative analysis method based on the calibration of single standard specimen |
| CN110398488A (en) * | 2019-06-11 | 2019-11-01 | 中国科学院合肥物质科学研究院 | Quantitative analysis of nonlinear method applied to laser induced breakdown spectroscopy |
| CN116482079A (en) * | 2023-04-03 | 2023-07-25 | 清华大学 | Detection method and system based on laser-induced breakdown spectroscopy |
-
2015
- 2015-03-10 CN CN201510101932.XA patent/CN104730042A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| JUAN DONG 等: "A method for improving the accuracy of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) using determined plasma temperature by genetic algorithm (GA)", 《J. ANAL. AT. SPECTROM》 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105203526A (en) * | 2015-09-22 | 2015-12-30 | 中国科学院上海技术物理研究所 | Calibration-free remote quantitative laser-induced breakdown spectroscopy analysis method |
| CN105203526B (en) * | 2015-09-22 | 2017-08-25 | 中国科学院上海技术物理研究所 | Exempt from the remote quantitative LIBS analysis method of calibration |
| CN107817239A (en) * | 2016-09-13 | 2018-03-20 | 中国科学院沈阳自动化研究所 | A kind of LIBS spectral correction methods based on plasma position information |
| CN107817239B (en) * | 2016-09-13 | 2019-06-18 | 中国科学院沈阳自动化研究所 | A kind of LIBS spectral correction method based on plasma position information |
| CN106841170A (en) * | 2016-12-05 | 2017-06-13 | 西北大学 | A kind of coal ash category identification method based on wavelet neural network algorithm combination LIBS technologies |
| CN108918474A (en) * | 2018-04-26 | 2018-11-30 | 安徽师范大学 | For reducing the matrix dilution process of laser induced breakdown spectroscopy self absorption effect |
| CN108918474B (en) * | 2018-04-26 | 2022-07-08 | 安徽师范大学 | Matrix dilution method for reducing self-absorption effect of laser-induced breakdown spectroscopy |
| CN108572177A (en) * | 2018-05-21 | 2018-09-25 | 中北大学 | The online constant temperature detection method of welding arc pollutant based on emission spectrum |
| CN109781711A (en) * | 2019-02-21 | 2019-05-21 | 华中科技大学 | A kind of laser induced breakdown spectroscopy quantitative analysis method based on the calibration of single standard specimen |
| CN110398488A (en) * | 2019-06-11 | 2019-11-01 | 中国科学院合肥物质科学研究院 | Quantitative analysis of nonlinear method applied to laser induced breakdown spectroscopy |
| CN110398488B (en) * | 2019-06-11 | 2021-09-07 | 中国科学院合肥物质科学研究院 | Nonlinear quantitative analysis method applied to laser-induced breakdown spectroscopy |
| CN116482079A (en) * | 2023-04-03 | 2023-07-25 | 清华大学 | Detection method and system based on laser-induced breakdown spectroscopy |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104730042A (en) | Method for improving free calibration analysis precision by combining genetic algorithm with laser induced breakdown spectroscopy | |
| CN102262076B (en) | Method for laser-induced breakdown spectroscopy element concentration determination based on spectral line combination | |
| CN104677875B (en) | A kind of three-dimensional fluorescence spectrum combines the method that parallel factor differentiates different brands Chinese liquor | |
| Li et al. | Analytical-performance improvement of laser-induced breakdown spectroscopy for steel using multi-spectral-line calibration with an artificial neural network | |
| CN101750404B (en) | Method for correcting plasma emission spectral line self-absorption effect | |
| CN103983617A (en) | Improved laser probe quantitative analysis method based on wavelet transform | |
| CN104596957A (en) | Estimation method for content of copper in soil on basis of visible-light near-infrared spectrum technology | |
| CN102830096A (en) | Method for measuring element concentration and correcting error based on artificial neural network | |
| Dong et al. | A method for improving the accuracy of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) using determined plasma temperature by genetic algorithm (GA) | |
| CN112051256B (en) | CNN model-based LIBS (laser induced breakdown spectroscopy) measurement method and system for content of element to be measured | |
| CN105486655A (en) | Rapid detection method for organic matters in soil based on infrared spectroscopic intelligent identification model | |
| CN107957411B (en) | Method and device for detecting maturity of oil source rock by holographic fluorescence | |
| CN106770190A (en) | Self-absorption effect produces effects the method answered in a kind of calibration of laser induced breakdown spectroscopy | |
| CN102410992B (en) | Simplified element measurement method through laser-induced plasma spectral standardization | |
| CN104483292A (en) | Multi-spectral-line calibration method for improving analysis precision of laser probe | |
| CN104730043A (en) | Method for measuring heavy metals in ink based on partial least squares | |
| Guodong et al. | A feature selection method combined with ridge regression and recursive feature elimination in quantitative analysis of laser induced breakdown spectroscopy | |
| CN103792214B (en) | A kind of improve the method for carbon element content certainty of measurement in iron and steel | |
| CN106442474B (en) | A kind of cement slurry three ratio measurement method based on Partial Least Squares | |
| CN109142251B (en) | LIBS quantitative analysis method of random forest auxiliary artificial neural network | |
| CN109521001A (en) | A kind of flying marking measuring method based on PSO and ε-SVR | |
| CN105277531A (en) | Grading-based coal characteristic measurement method | |
| CN107941758A (en) | A kind of coal quality measurement of caloric value method based on Pretreated spectra | |
| CN102103079B (en) | Spectrum analysis method | |
| CN115541563A (en) | Element quantitative analysis method based on laser-induced breakdown spectroscopy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20150624 |
|
| WD01 | Invention patent application deemed withdrawn after publication |