CN109374566A - A kind of measuring method and measurement system of mixed alcohol content - Google Patents
A kind of measuring method and measurement system of mixed alcohol content Download PDFInfo
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- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 title claims abstract description 253
- 238000000034 method Methods 0.000 title claims abstract description 62
- 238000005259 measurement Methods 0.000 title claims abstract description 21
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims abstract description 49
- 238000002329 infrared spectrum Methods 0.000 claims abstract description 42
- 238000004088 simulation Methods 0.000 claims abstract description 39
- 238000001228 spectrum Methods 0.000 claims abstract description 38
- 238000004458 analytical method Methods 0.000 claims abstract description 31
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000002835 absorbance Methods 0.000 claims description 92
- 230000003595 spectral effect Effects 0.000 claims description 26
- 239000000203 mixture Substances 0.000 claims description 20
- 238000013210 evaluation model Methods 0.000 claims description 15
- 238000012417 linear regression Methods 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 238000004566 IR spectroscopy Methods 0.000 claims description 4
- 208000011580 syndromic disease Diseases 0.000 claims description 4
- 238000004497 NIR spectroscopy Methods 0.000 claims description 2
- 238000012360 testing method Methods 0.000 abstract description 12
- 238000004611 spectroscopical analysis Methods 0.000 abstract description 7
- 238000004817 gas chromatography Methods 0.000 abstract description 6
- 238000004364 calculation method Methods 0.000 abstract description 3
- 238000002474 experimental method Methods 0.000 abstract description 3
- 239000012086 standard solution Substances 0.000 abstract description 3
- 235000011187 glycerol Nutrition 0.000 description 15
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- SNIOPGDIGTZGOP-UHFFFAOYSA-N Nitroglycerin Chemical compound [O-][N+](=O)OCC(O[N+]([O-])=O)CO[N+]([O-])=O SNIOPGDIGTZGOP-UHFFFAOYSA-N 0.000 description 3
- 230000008033 biological extinction Effects 0.000 description 3
- UQXKXGWGFRWILX-UHFFFAOYSA-N ethylene glycol dinitrate Chemical compound O=N(=O)OCCON(=O)=O UQXKXGWGFRWILX-UHFFFAOYSA-N 0.000 description 3
- 229960003711 glyceryl trinitrate Drugs 0.000 description 3
- QUAMCNNWODGSJA-UHFFFAOYSA-N 1,1-dinitrooxybutyl nitrate Chemical compound CCCC(O[N+]([O-])=O)(O[N+]([O-])=O)O[N+]([O-])=O QUAMCNNWODGSJA-UHFFFAOYSA-N 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- -1 nitric acid ester Chemical class 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- AGCQZYRSTIRJFM-UHFFFAOYSA-N triethylene glycol dinitrate Chemical compound [O-][N+](=O)OCCOCCOCCO[N+]([O-])=O AGCQZYRSTIRJFM-UHFFFAOYSA-N 0.000 description 2
- GCVXUERSYPSYQA-UHFFFAOYSA-N 2-[2-(2-hydroxyethoxy)ethoxy]ethyl nitrate Chemical compound OCCOCCOCCO[N+]([O-])=O GCVXUERSYPSYQA-UHFFFAOYSA-N 0.000 description 1
- 102000004882 Lipase Human genes 0.000 description 1
- 108090001060 Lipase Proteins 0.000 description 1
- 239000004367 Lipase Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 235000019421 lipase Nutrition 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 239000003380 propellant Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/359—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3577—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing liquids, e.g. polluted water
Abstract
The present invention relates to a kind of measuring method of mixed alcohol content and measurement systems, based on spectrum principle of stacking, utilize the near infrared spectrum of pure sample, the spectrogram of mixed alcohol is formed by digital simulation, interference is reduced or eliminated by integral calculation, the quantitative model of glycerol and triethylene-glycol content and spectroscopic data in mixed alcohol is then established with the spectroscopic data least square method or Partial Least Squares of simulation；This method does not need to prepare series standard solution, sample does not need to pre-process, directly carry out spectrum test, many experiments work can be reduced, the quick analysis test of operation field is suitable for, the present invention enormously simplifies measurement process, improve measurement efficiency, cost is significantly reduced, and the method for the present invention is suitable with gas chromatography accuracy, there is stronger practicability.
Description
Technical field
The present invention relates to a kind of spectroscopy technologies that mixed alcohol content is quickly measured in mixed nitrate Lipase absobed, and in particular to one
The measuring method and measurement system of the mixed alcohol content of kind, belong to analysis and testing technology field.
Background technique
Meet mechanical property requirements simultaneously to improve propellant energy, needs to use nitrate as energetic plasticiser, often
Nitrate has nitroglycerine (NG), dinitroglycol (EGDN), diethlene glycol dinitrate (DEGDN), triethylene glycol dinitrate
(TEGDN), they are actually often used in mixed way in formula by butanetriol trinitrate (BTTN) etc..Mixed alcohol refers to glycerol and two
The mixture of contracting triethylene glycol is the primary raw material for synthesizing naked nitric acid ester.It is general by adjusting in mixed alcohol in process of production
The ratio of glycerol and triethylene-glycol controls nitroglycerine and triethylene-glycol nitrate in final products naked nitric acid ester
Ratio.The ratio of glycerol and triethylene-glycol can be measured using the methods of gas-chromatography, liquid chromatogram in mixed alcohol, but
It is all unable to direct injected, needs to be weighed according to conventional analytical procedure, dilute, a series of samples pre-treatment such as constant volume；It surveys
Amount process is complicated, low efficiency, at high cost.
Summary of the invention
It is an object of the invention to overcome the drawbacks described above of the prior art, a kind of measuring method of mixed alcohol content is provided, it should
Method is based on spectrum principle of stacking and forms the spectrogram of mixed alcohol by digital simulation using the near infrared spectrum of pure sample, do not need
Series standard solution is prepared, sample does not need to pre-process, directly progress spectrum test, it is possible to reduce many experiments work,
Measurement process complexity is reduced, the quick analysis test of operation field is suitable for.
Another object of the present invention is that providing a kind of measurement system of mixed alcohol content
Above-mentioned purpose of the invention is achieved by following technical solution:
A kind of measuring method of mixed alcohol content, comprising:
Establish the simulation near infrared spectrum difference model of mixed alcohol；
Concentration analysis model is established according to the simulation near infrared spectrum difference model of the mixed alcohol；
According to the mixed alcohol simulation near infrared spectrum difference model and concentration analysis model foundation mix alcohol absorbance with
The related coefficient evaluation model of concentration；
Adjusting wavelength numerical value is obtained according to the related coefficient evaluation model of the absorbance of the mixed alcohol and concentration；
The infrared spectrogram for measuring mixed alcohol, obtains corresponding spectral absorbance in the adjusting wavelength numberical range；
According to corresponding spectral absorbance in the adjusting wavelength numerical value and adjusting wavelength numberical range, the mixed alcohol is utilized
Simulation near infrared spectrum difference model obtain the difference absorbance of mixed alcohol；
According to the difference absorbance of the mixed alcohol, the content of each alcohol in mixed alcohol is obtained using the concentration analysis model.
In the measuring method of above-mentioned mixed alcohol content, the specific method of the simulation near infrared spectrum difference model of mixed alcohol is established
As follows, the mixed alcohol includes alcohol A and alcohol B:
(1), the pass between mixed alcohol absorbance and alcohol A absorbance, alcohol B absorbance is obtained according to the spectrum expression formula of mixture
It is that formula is as follows:
Wherein: α is mass fraction/molar concentration conversion coefficient；AGL(λ) is alcohol A absorbance；ATG(λ) is alcohol B absorbance；
Noise is random error；Amix(λ) is mixed alcohol absorbance；
(2), according to the relational expression mixed between alcohol absorbance and alcohol A absorbance, alcohol B absorbance, select related coefficient higher
The spectral signals of two wave bands seek respective average value, and make the difference to obtain the simulation near infrared spectrum difference model of mixed alcohol such as
Under:
Wherein: Δ AsamFor the difference absorbance for mixing alcohol, AλAs mixed alcohol absorbance Amix(λ)；λ 1, λ 2 be related coefficient compared with
The starting and ending wavelength of a high wave band, λ 3, λ 4 are the starting and ending wavelength of another higher wave band of related coefficient.
In the measuring method of above-mentioned mixed alcohol content, the correlation of the spectral signal of higher two wave bands of related coefficient
The absolute value of coefficient is not less than 0.8.
In the measuring method of above-mentioned mixed alcohol content, the spectrum expression formula of mixture is as follows in the step (1):
Wherein: Ai(λ) is absorbance；ciFor substance withdrawl syndrome；ρiFor density；wmiFor molal weight.
In the measuring method of above-mentioned mixed alcohol content, the mass fraction/molar concentration conversion coefficient α expression formula is such as
Under:
α=ωGLρTG/ωTGρGL
And meet following relationship:
Wherein: ωGLFor the mass fraction of alcohol A；ρGLFor the density of alcohol A；ωTGFor the mass fraction of alcohol B；ρTGFor the close of alcohol B
Degree；cGLFor the absorbance of alcohol A；cTGFor the absorbance of alcohol B；wGLFor the molal weight of alcohol A；wTGFor the molal weight of alcohol B.
In the measuring method of above-mentioned mixed alcohol content, the value of the random error noise is mixed spectra2%~﹢ of ﹣ 2%.
In the measuring method of above-mentioned mixed alcohol content, according to the simulation near-infrared spectroscopy of the mixed alcohol, minimum is utilized
Square law carries out linear regression, and it is as follows to establish concentration analysis model:
Csam=a Δ Asam+b
Wherein: CsamFor the content of alcohol A or alcohol B in mixed alcohol；A, b is the linear regression coeffficient of alcohol A or the line of alcohol B in mixed alcohol
Property regression coefficient.
In the measuring method of above-mentioned mixed alcohol content, according to the simulation near infrared spectrum difference model and concentration of the mixed alcohol
The related coefficient evaluation model that analysis model establishes the absorbance and concentration of mixing alcohol is as follows:
Wherein: R is related coefficient；For the standard deviation of concentration,For the standard deviation of absorbance, Cov
(Csam,ΔAsam) covariance between concentration and absorbance.
In the measuring method of above-mentioned mixed alcohol content, mould is evaluated according to the related coefficient of the absorbance of the mixed alcohol and concentration
The method that type obtains adjusting wavelength numerical value are as follows: choose corresponding λ 1 when coefficient R maximum, λ 2, λ 3, λ 4 and be used as adjusting wavelength number
Value；The adjusting wavelength numberical range is 1~λ of λ 2 and 3~λ of λ 4.
In the measuring method of above-mentioned mixed alcohol content, when measuring the infrared spectrogram of mixed alcohol, measurement light path for 5mm~
10mm, the near infrared spectrum that wave-length coverage is 1100~1400nm.
In the measuring method of above-mentioned mixed alcohol content, the mixed alcohol includes glycerol and triethylene-glycol.
A kind of measurement system of mixed alcohol content, including model building module, wavelength obtain module and alcohol content computing module,
Wherein:
Model building module, establishes the simulation near infrared spectrum difference model of mixed alcohol, and the simulation according to the mixed alcohol is closely red
External spectrum difference model establishes concentration analysis model；According to the simulation near infrared spectrum difference model and concentration analysis of the mixed alcohol
Model foundation mixes the absorbance of alcohol and the related coefficient evaluation model of concentration, by the phase relation of the absorbance and concentration of the mixed alcohol
Number evaluation model is sent to wavelength and obtains module, by the simulation near infrared spectrum difference model and concentration analysis model of the mixed alcohol
It is sent to alcohol content computing module；
Wavelength obtains module, according to the related coefficient of absorbance and concentration from the received mixed alcohol of model building module
Evaluation model obtains adjusting wavelength numerical value, and the adjusting wavelength numerical value is sent to alcohol content computing module；
Alcohol content computing module receives the infrared spectrogram for the mixed alcohol that the external measurement sent obtains, according to described infrared
Spectrogram obtains corresponding spectral absorbance in the adjusting wavelength numberical range；According to the adjusting wavelength numerical value and adjust wave
Corresponding spectral absorbance in long numberical range obtains the difference of mixed alcohol using the simulation near infrared spectrum difference model of the mixed alcohol
Divide absorbance；According to the difference absorbance of the mixed alcohol, the content of each alcohol in mixed alcohol is obtained using the concentration analysis model.
Compared with prior art, the present invention has the following advantages:
(1), a kind of measuring method that mixed alcohol content is carried out using spectral principle proposed by the present invention, difference and traditional measurement
Method, the present invention is based on spectrum principle of stackings to form the spectrum of mixed alcohol by digital simulation using the near infrared spectrum of pure sample
Figure, reduces or eliminates interference by integral calculation, then with the spectroscopic data least square method or Partial Least Squares of simulation
Establish the quantitative model of glycerol and triethylene-glycol content and spectroscopic data in mixed alcohol；This method does not need to prepare series standard
Solution, sample do not need to pre-process, directly progress spectrum test, it is possible to reduce it is existing to be suitable for operation for many experiments work
The quick analysis test of field.
(2), mixed alcohol content measuring method proposed by the present invention, according to the related coefficient of mixed the alcohol absorbance and concentration of foundation
The available optimal adjusting wavelength numerical value of evaluation model, when actually carrying out mixed alcohol content measurement, it is only necessary to according to the infrared of mixed alcohol
Spectrogram finds the corresponding spectral absorbance of the adjusting wavelength, and the difference extinction of mixed alcohol is calculated using infrared spectroscopy model
Degree recycles concentration analysis model that the content of each alcohol in mixed alcohol is calculated, and alcohol only can be obtained by the calculating of two steps and contain
Amount, enormously simplifies measurement process, improves measurement efficiency, significantly reduces cost.
(3), the content and actual measurement of each alcohol in the mixed alcohol obtained using mixed alcohol content measuring method proposed by the present invention
It is worth the goodness of fit with higher, i.e. the method for the present invention is suitable with gas chromatography accuracy, has stronger practicability.
Detailed description of the invention
Fig. 1 is the measuring method flow chart of the mixed alcohol content of the present invention；
Fig. 2 is the pure sample atlas of near infrared spectra of light path 1mm in the embodiment of the present invention 1；
Fig. 3 is the pure sample atlas of near infrared spectra of light path 10mm in the embodiment of the present invention 1；
Fig. 4 is to simulate atlas of near infrared spectra in the embodiment of the present invention 1；
Fig. 5 is the atlas of near infrared spectra of actual sample in the embodiment of the present invention 1；
Fig. 6 is the related coefficient spectrogram of spectrum change and glycerol content in mixed alcohol in the embodiment of the present invention 1；
Fig. 7 is the standard curve that different condition models in the embodiment of the present invention 1.
Specific embodiment
The present invention is described in further detail in the following with reference to the drawings and specific embodiments:
In near infrared spectrum, substance is closely related in the absorbance of af at wavelength lambda and the characteristic of substance, with the object in sample
The content of matter, light transmission light path are directly proportional.One section of curve of spectrum can be expressed as the function of wavelength X:
A (λ)=cl ε (λ) ... ... ... ... ... ... ... ... ... (1)
The near infrared spectrum of mixture is the superposition of each group spectral, can be indicated are as follows:
Amix(λ)=∑ cilεi(λ)……………………………………….(2)
According to the relationship of the amount concentration of liquid substance and density and molal weight, by simply deriving available mole of suction
The expression formula (4) of backscatter extinction logarithmic ratio:
It brings formula (4) into formula (2), the spectrum expression formula of mixture can be obtained:
Wherein:
Ai(λ) is absorbance (function of wavelength X)；
ciFor substance withdrawl syndrome；mol/L；
L is light path；cm；
ε (λ) is molar absorption coefficient, L/mol.cm；
ρiFor density；g/ml；
wmiFor molal weight；g/mol.
Specifically, it includes alcohol A and alcohol B that alcohol is mixed in the embodiment of the present invention, and the substance withdrawl syndrome for mixing alcohol A and alcohol B in alcohol can
To be obtained from their mass fraction (ω) with formula (6) approximate calculation, subscript GL and TG respectively represent alcohol A and alcohol B in formula.
Wherein: ωGLFor the mass fraction of alcohol A；ρGLFor the density of alcohol A；ωTGFor the mass fraction of alcohol B；ρTGFor the close of alcohol B
Degree；cGLFor the absorbance of alcohol A；cTGFor the absorbance of alcohol B；wGLFor the molal weight of alcohol A；wTGFor the molal weight of alcohol B.
Bring formula (6) into formula (5) and abbreviation:
It enables: α=ωGLρTG/ωTGρGL, then:
Formula (8) is the relational expression of mixed alcohol spectrum and alcohol A, alcohol B spectrum.It can be calculated from alcohol A, alcohol B spectrum by formula (8)
Alcohol spectrum is mixed out.In order to make the mixed alcohol spectrum being calculated closer to real spectrum, one is added in formula (8) with chance error
Difference is used for analog meter noise, then obtains formula (9):
The near infrared spectrum of mixed alcohol is simulated by formula (9), and analysis model is established with the near infrared spectrum of simulation.
In order to improve accuracy of measurement, it is necessary to signal-to-noise ratio is improved, to slacken the interference of noise.Because the sum of random error is
Zero, therefore noise signal, raising signal-to-noise ratio can be weakened by way of calculating spectrum integral.Specific practice is selection phase relation
The spectral signal of higher two wave bands of number is integrated and is averaged, and the difference of peaks and troughs is then calculated, with value work
To mix the difference absorbance of alcohol, then with least square method linear regression is carried out, establishes the analysis model of concentration.
Csam=a Δ Asam+b………………………………………………(11)
Formula (10), (11) are modeling formula, and model optimization mainly passes through 4 four adjusting wavelength λ 1, λ 2, λ 3, λ parameter value realities
Now, with related coefficient evaluation model superiority and inferiority:
Wherein:For the standard deviation of concentration,For the standard deviation of absorbance, Cov (Csam,ΔAsam) it is concentration
Covariance between absorbance.
As shown in Figure 1, the measuring method that the present invention mixes alcohol content specifically comprises the following steps, it include alcohol A and alcohol B with mixed alcohol
For:
Step (1), the simulation near infrared spectrum difference model for establishing mixed alcohol, method particularly includes:
(1.1), it is obtained between mixed alcohol absorbance and alcohol A absorbance, alcohol B absorbance according to the spectrum expression formula of mixture
Relational expression is as follows:
Wherein: α is mass fraction/molar concentration conversion coefficient；AGL(λ) is alcohol A absorbance；ATG(λ) is alcohol B absorbance；
Noise is random error；Amix(λ) is mixed alcohol absorbance；
The value of random error noise is mixed spectra2%~﹢ of ﹣ 2%.
(1.2), according to the relational expression mixed between alcohol absorbance and alcohol A absorbance, alcohol B absorbance, select related coefficient compared with
The spectral signal of two high wave bands seeks respective average value, and makes the difference to obtain the simulation near infrared spectrum difference model of mixed alcohol
It is as follows:
Wherein: Δ AsamFor the difference absorbance for mixing alcohol, AλAs mixed alcohol absorbance Amix(λ)；λ 1, λ 2 are related coefficient
The starting and ending wavelength of a higher wave band, λ 3, λ 4 are the starting and ending wave of another higher wave band of related coefficient
It is long.
Specifically, the related coefficient of the spectral signal of higher two wave bands of related coefficient is not less than in the embodiment of the present invention
0.8, it is negative that two wave bands can be one positive one, as shown in figure 5, the related coefficient of two wave bands is respectively close to -1 and ﹢ 1.Two waves
Section is being also possible to two just or two is negative, such as close to -1 or close to ﹢ 1.
Step (2), basis mix the simulation near infrared spectrum difference model of alcohol, carry out linear regression using least square method,
It is as follows to establish concentration analysis model:
Csam=a Δ Asam+b
Wherein: CsamFor the content of alcohol A or alcohol B in mixed alcohol；A, b is the linear regression coeffficient of alcohol A or the line of alcohol B in mixed alcohol
Property regression coefficient.
Step (3), the extinction that alcohol is mixed according to the simulation near infrared spectrum difference model and concentration analysis model foundation that mix alcohol
It spends as follows with the related coefficient evaluation model of concentration:
Wherein: R is related coefficient；For the standard deviation of concentration,For the standard deviation of absorbance, Cov (Csam,
ΔAsam) covariance between concentration and absorbance.
Step (4) obtains adjusting wavelength numerical value according to the related coefficient evaluation model of the absorbance and concentration of mixing alcohol, specifically
Method are as follows: choose corresponding λ 1 when coefficient R maximum, λ 2, λ 3, λ 4 and be used as adjusting wavelength numerical value, such as selection coefficient R
Most proximity -1 or the λ 1 when ﹢ 1, λ 2, λ 3, λ 4 are used as adjusting wavelength numerical value.
Step (5), the infrared spectrogram for measuring mixed alcohol, obtain corresponding spectral absorbance in adjusting wavelength numberical range.
When measuring the infrared spectrogram of mixed alcohol, test light path is 5mm~10mm, the near infrared light that wave-length coverage is 1100~1400nm
Spectrum.Obtain wavelength in 4 range of wavelength and its corresponding spectral absorbance and 3~λ of λ in 1~λ of λ, 2 range and its right
The spectral absorbance answered.
Step (6), according to corresponding spectral absorbance within the scope of adjusting wavelength and adjusting wavelength, the simulation using mixed alcohol is close
Infrared spectroscopy difference model obtains the difference absorbance of mixed alcohol.Calculated using such as Imitating near infrared spectrum difference model
Obtain the difference absorbance Δ A of mixed alcoholsam。
Step (7), basis mix the difference absorbance Δ A of alcoholsam, containing for each alcohol in mixed alcohol is obtained using concentration analysis model
Amount.It is calculated separately to obtain the content C of alcohol A in mixed alcohol according to the concentration analysis model of following alcohol A and alcohol Bsam-GLAnd alcohol B
Content Csam-TG。
Csam-GL=aGL·ΔAsam+bGL
Csam-TG=aTG·ΔAsam+bTG。
Embodiment 1
For including pure glycerin and triethylene-glycol in mixed alcohol.As Fig. 2, Fig. 3 be respectively using light path be 1mm and
The near infrared spectrum that the sample cell of 10mm obtains.Although spectrum wider with the wave-length coverage that 1mm sample cell can measure, obtaining
Information is more abundant, but since glycerol, triethylene-glycol and mixed alcohol sample are all very sticky, is operated with 1mm sample cell sample introduction
Relatively difficult, the bubble that sample introduction is formed is not easy to exclude, and easily influences the accuracy of spectrum.The spectrogram obtained using 10mm sample cell
2, wave crest peak absorbance is about 0.5, and trough is in the lesser range of absorbency of theoretical error for 0.1, therefore selects light path
The spectrum of 10mm, 1100~1400nm of wavelength are as measurement spectrum.
In order to simulate mixed alcohol near infrared spectrum, need to test the spectrum of pure glycerin, triethylene-glycol first.Select 10mm
Sample cell, measure 1100~1400nm of wavelength infrared spectroscopy.
Mix glycerol in alcohol, the content of triethylene-glycol is generally 40%~60% or so.As intermediate value, using Fig. 3
Spectroscopic data and formula (9) simulation calculate glycerol content 35%~45%, triethylene-glycol content be 55%~65%, it may be assumed that
ωGL=35%~45%, ωTG=65%~55% near infrared spectrum, Fig. 4 are the mixed alcohol spectrograms that simulation obtains, and Fig. 5 is
The spectrogram of practical mixed alcohol sample.The main feature of obvious simulated spectra and actual spectrum is completely the same.
From fig. 4, it can be seen that in ωGLIn=35%~45% range, mixed alcohol spectrum has more apparent variation, but does not show
It writes.It is directly measured with Lambert-Beer's law, can there is large error.The main reason is that the instrument noise of simulation can be done
Sample signal is disturbed, brings it about certain deviation, this deviation and the true noise of instrument are comparable.Fig. 6 is spectrum change
With the spectrum of correlation coefficient of glycerol content in mixed alcohol, it is clear that in the higher wave band of related coefficient, glycerol and triethylene-glycol
SPECTRAL DIVERSITY is larger, otherwise when the SPECTRAL DIVERSITY of glycerol and triethylene-glycol is smaller, related coefficient will be deteriorated.
Model the data setting used are as follows:
ωGL=0.35~0.45, d ωGL=0.01 (mass fraction step-length)；
ωTG=0.65~0.55, d ωTG=-0.01 (mass fraction step-length)；
|noise|≤0.0025。
Fig. 7 be shown it is several obtain standard curve and related coefficient using different modeling conditions and method, Fig. 7 a, 7b,
7c and 7d is respectively different modeling conditions and standard curve and related coefficient that method obtains, and wherein the tropic of Fig. 7 c is optimization
1~λ of λ 4 afterwards is respectively 1210,1230,1260,1370nm, the calculated result modeled by formula (10) and (11).
Actual sample test need to only be substituted into spectroscopic data by the atlas of near infrared spectra for modeling same condition test sample
Formula (10) and (11), can calculate the content of each component in sample.It contracts to glycerol in 11 kinds of mixed alcohol samples of preparation and two
Triethylene glycol content is measured.The series of samples is determined using gas chromatography simultaneously, and with standard specimen to integral
Area is corrected.Test result is shown in Table 1.
1 distinct methods measurement result of table
Near-infrared sunykatuib analysis can be calculated from 1 data of table, the relative error limit of gas-chromatography be respectively as follows: -2.1%~
1.2%, -1.6%~2.2%, prediction residual quadratic sum (PRESS) is respectively as follows: 0.54%, 0.53%, it is possible thereby to judge, this
The simulation of invention near-infrared is suitable with gas chromatography accuracy.
The above, optimal specific embodiment only of the invention, but scope of protection of the present invention is not limited thereto,
In the technical scope disclosed by the present invention, any changes or substitutions that can be easily thought of by anyone skilled in the art,
It should be covered by the protection scope of the present invention.
The content that description in the present invention is not described in detail belongs to the well-known technique of professional and technical personnel in the field.
Claims (12)
1. a kind of measuring method of mixed alcohol content, it is characterised in that: include:
Establish the simulation near infrared spectrum difference model of mixed alcohol；
Concentration analysis model is established according to the simulation near infrared spectrum difference model of the mixed alcohol；
The absorbance and concentration of alcohol are mixed according to the simulation near infrared spectrum difference model and concentration analysis model foundation of the mixed alcohol
Related coefficient evaluation model；
Adjusting wavelength numerical value is obtained according to the related coefficient evaluation model of the absorbance of the mixed alcohol and concentration；
The infrared spectrogram for measuring mixed alcohol, obtains corresponding spectral absorbance in the adjusting wavelength numberical range；
According to corresponding spectral absorbance in the adjusting wavelength numerical value and adjusting wavelength numberical range, the mould of the mixed alcohol is utilized
Quasi- near infrared spectrum difference model obtains the difference absorbance of mixed alcohol；
According to the difference absorbance of the mixed alcohol, the content of each alcohol in mixed alcohol is obtained using the concentration analysis model.
2. the measuring method of mixed alcohol content according to claim 1, it is characterised in that: establish the simulation near infrared light of mixed alcohol
The specific method is as follows for spectral difference sub-model, and the mixed alcohol includes alcohol A and alcohol B:
(1), the relational expression between mixed alcohol absorbance and alcohol A absorbance, alcohol B absorbance is obtained according to the spectrum expression formula of mixture
It is as follows:
Wherein: α is mass fraction/molar concentration conversion coefficient；AGL(λ) is alcohol A absorbance；ATG(λ) is alcohol B absorbance；noise
For random error；Amix(λ) is mixed alcohol absorbance；
(2), according to the relational expression mixed between alcohol absorbance and alcohol A absorbance, alcohol B absorbance, related coefficient higher two is selected
The spectral signal of a wave band seeks respective average value, and the simulation near infrared spectrum difference model for making the difference to obtain mixed alcohol is as follows:
Wherein: Δ AsamFor the difference absorbance for mixing alcohol, AλAs mixed alcohol absorbance Amix(λ)；λ 1, λ 2 are that related coefficient is higher
The starting and ending wavelength of one wave band, λ 3, λ 4 are the starting and ending wavelength of another higher wave band of related coefficient.
3. the measuring method of mixed alcohol content according to claim 2, it is characterised in that: higher two of the related coefficient
The absolute value of the related coefficient of the spectral signal of wave band is not less than 0.8.
4. the measuring method of mixed alcohol content according to claim 2, it is characterised in that: mixture in the step (1)
Spectrum expression formula is as follows:
Wherein: Ai(λ) is absorbance；ciFor substance withdrawl syndrome；ρiFor density；wmiFor molal weight.
5. the measuring method of mixed alcohol content according to claim 2, it is characterised in that: the mass fraction/molar concentration
The expression formula of conversion coefficient α is as follows:
α=ωGLρTG/ωTGρGL
And meet following relationship:
Wherein: ωGLFor the mass fraction of alcohol A；ρGLFor the density of alcohol A；ωTGFor the mass fraction of alcohol B；ρTGFor the density of alcohol B；
cGLFor the absorbance of alcohol A；cTGFor the absorbance of alcohol B；wGLFor the molal weight of alcohol A；wTGFor the molal weight of alcohol B.
6. the measuring method of mixed alcohol content according to claim 2, it is characterised in that: the random error noise's takes
Value is mixed spectra2%~﹢ of ﹣ 2%.
7. the measuring method of mixed alcohol content described according to claim 1~one of 6, it is characterised in that: according to the mixed alcohol
Near-infrared spectroscopy is simulated, linear regression is carried out using least square method, it is as follows to establish concentration analysis model:
Csam=a Δ Asam+b
Wherein: CsamFor the content of alcohol A or alcohol B in mixed alcohol；A, b is that the linear regression coeffficient of alcohol A or the linear of alcohol B return in mixed alcohol
Return coefficient.
8. the measuring method of mixed alcohol content according to claim 7, it is characterised in that: the simulation according to the mixed alcohol is closely red
The related coefficient evaluation model of the absorbance and concentration of external spectrum difference model and the mixed alcohol of concentration analysis model foundation is as follows:
Wherein: R is related coefficient；For the standard deviation of concentration,For the standard deviation of absorbance, Cov (Csam,Δ
Asam) covariance between concentration and absorbance.
9. the measuring method of mixed alcohol content according to claim 8, it is characterised in that: according to the absorbance of the mixed alcohol with
The method that the related coefficient evaluation model of concentration obtains adjusting wavelength numerical value are as follows: choose corresponding λ 1, λ when coefficient R maximum
2, λ 3, λ 4 are used as adjusting wavelength numerical value；The adjusting wavelength numberical range is 1~λ of λ 2 and 3~λ of λ 4.
10. the measuring method of mixed alcohol content according to claim 1, it is characterised in that: measure the infrared spectrogram of mixed alcohol
When, measurement light path be 5mm~10mm, the near infrared spectrum that wave-length coverage is 1100~1400nm.
11. according to claim 1~6, measuring method of mixed alcohol content described in one of 8~10, it is characterised in that: the mixed alcohol
Including glycerol and triethylene-glycol.
12. a kind of measurement system of mixed alcohol content, it is characterised in that: obtain module including model building module, wavelength and alcohol contains
Measure computing module, in which:
Model building module establishes the simulation near infrared spectrum difference model of mixed alcohol, according to the simulation near infrared light of the mixed alcohol
Spectral difference sub-model establishes concentration analysis model；According to the simulation near infrared spectrum difference model and concentration analysis model of the mixed alcohol
The absorbance of mixed alcohol and the related coefficient evaluation model of concentration are established, the related coefficient of the absorbance of the mixed alcohol and concentration is commented
Valence model is sent to wavelength and obtains module, and the simulation near infrared spectrum difference model of the mixed alcohol and concentration analysis model are sent
Give alcohol content computing module；
Wavelength obtains module, is evaluated according to the related coefficient of absorbance and concentration from the received mixed alcohol of model building module
Model obtains adjusting wavelength numerical value, and the adjusting wavelength numerical value is sent to alcohol content computing module；
Alcohol content computing module receives the infrared spectrogram for the mixed alcohol that the external measurement sent obtains, according to the infrared spectroscopy
Figure obtains corresponding spectral absorbance in the adjusting wavelength numberical range；According to the adjusting wavelength numerical value and adjusting wavelength number
It is worth corresponding spectral absorbance in range, is inhaled using the difference that the simulation near infrared spectrum difference model of the mixed alcohol obtains mixed alcohol
Luminosity；According to the difference absorbance of the mixed alcohol, the content of each alcohol in mixed alcohol is obtained using the concentration analysis model.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110542669A (en) * | 2019-08-30 | 2019-12-06 | 山西北方兴安化学工业有限公司 | Rapid analysis method of mirabilite and glycerin waste acid components |
| CN113588583A (en) * | 2021-07-28 | 2021-11-02 | 南京红松信息技术有限公司 | Water quality index monitoring system based on full spectrum and water quality monitoring method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101303295A (en) * | 2008-07-10 | 2008-11-12 | 天津三星电机有限公司 | Fast analysis method of infrared spectrum quantitative analysis mixing solution composition |
| CN102608061A (en) * | 2012-03-21 | 2012-07-25 | 西安交通大学 | Improved method for extracting Fourier transformation infrared spectrum characteristic variable of multi-component gas by aid of TR (Tikhonov regularization) |
| CN103163128A (en) * | 2013-03-13 | 2013-06-19 | 重庆大学 | Method for determining content of amylopectin and amylose in broomcorn |
| CN103257117A (en) * | 2013-02-25 | 2013-08-21 | 中国科学院安徽光学精密机械研究所 | Rapid gasoline component measurement system |
| CN104089911A (en) * | 2014-06-27 | 2014-10-08 | 桂林电子科技大学 | Spectral model transmission method based on unary linear regression |
| CN104849232A (en) * | 2015-04-27 | 2015-08-19 | 中国农业科学院蜜蜂研究所 | Method for rapid detection of contents of water and protein in royal jelly |
| CN106483095A (en) * | 2016-10-13 | 2017-03-08 | 天津工业大学 | A kind of method of each component oil content in quick, accurate quantitative analysis quaternary ready-mixed oil |
-
2018
- 2018-12-17 CN CN201811545085.6A patent/CN109374566B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101303295A (en) * | 2008-07-10 | 2008-11-12 | 天津三星电机有限公司 | Fast analysis method of infrared spectrum quantitative analysis mixing solution composition |
| CN102608061A (en) * | 2012-03-21 | 2012-07-25 | 西安交通大学 | Improved method for extracting Fourier transformation infrared spectrum characteristic variable of multi-component gas by aid of TR (Tikhonov regularization) |
| CN103257117A (en) * | 2013-02-25 | 2013-08-21 | 中国科学院安徽光学精密机械研究所 | Rapid gasoline component measurement system |
| CN103163128A (en) * | 2013-03-13 | 2013-06-19 | 重庆大学 | Method for determining content of amylopectin and amylose in broomcorn |
| CN104089911A (en) * | 2014-06-27 | 2014-10-08 | 桂林电子科技大学 | Spectral model transmission method based on unary linear regression |
| CN104849232A (en) * | 2015-04-27 | 2015-08-19 | 中国农业科学院蜜蜂研究所 | Method for rapid detection of contents of water and protein in royal jelly |
| CN106483095A (en) * | 2016-10-13 | 2017-03-08 | 天津工业大学 | A kind of method of each component oil content in quick, accurate quantitative analysis quaternary ready-mixed oil |
Non-Patent Citations (4)
| Title |
|---|
| MEGAN TWOMEY: "Conjugated polymer based biomaterials through controlled self-assembly", 《INSTITUTIONAL REPOSITORY》 * |
| 吴兆娜: "近红外光谱定量建模技术研究", 《中国优秀硕士学位论文全文数据库》 * |
| 胡露 等: "单一窄波段光吸收涂层的制备及性能研究", 《化学与黏合》 * |
| 钟建毅 等: "基于小波变换的多组分药物计算光度分析法", 《光谱学与光谱分析》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110542669A (en) * | 2019-08-30 | 2019-12-06 | 山西北方兴安化学工业有限公司 | Rapid analysis method of mirabilite and glycerin waste acid components |
| CN113588583A (en) * | 2021-07-28 | 2021-11-02 | 南京红松信息技术有限公司 | Water quality index monitoring system based on full spectrum and water quality monitoring method |
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