CN105675521B - A kind of method and detection device based on sensitive membrane on-line checking water pH value - Google Patents
A kind of method and detection device based on sensitive membrane on-line checking water pH value Download PDFInfo
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Abstract
The present invention provides a kind of method based on sensitive membrane on-line checking water pH value, comprises the following steps：Prepare sensitive membrane；The different buffer solution of pH value is configured, obtains the absorption spectrum of sensitive membrane；Calculate molar absorption coefficient ratio e1、e2、e3With multigroup absorbance ratio R；Linear regression curves are prepared using molar absorption coefficient ratio and multigroup absorbance ratio, obtain the slope 1/n and intercept pK of linear regression curvesa；Sensitive membrane is immersed into water body to be measured, calculates the absorbance ratio R under conditions present；By molar absorption coefficient ratio e1、e2、e3, slope 1/n and intercept pKa, the absorbance ratio R under conditions presentXFormula is substituted into, calculates the pH value of water body to be measured.The invention also proposes a kind of detection device based on sensitive membrane on-line checking water pH value.The present invention has the advantages that accuracy of detection height and using flexible.
Description
Technical field
The invention belongs to environmental monitoring technology field, and specifically, more particularly to one kind is based on sensitive membrane on-line checking water
The method and detection device of body pH value.
Background technology
PH value is the important parameter of water quality monitoring and evaluation, and monitoring result is received for ECOLOGICAL ENVIRONMENTAL MONITORING, Ocean acidification, carbon
Branch, geochemical cycle are respectively provided with significance.
The method for monitoring water pH value on-line in the prior art is mainly electrode method and photometry.Used in electrode method measurement
PH electrode volumes it is small, energy consumption is low, reusable and measurement frequency is high, but long-time service current potential can occur drift, signal hold
Easily by electromagnetic interference, have that precision is low, needs the defects of periodic calibration.And the photometry based on indicator injection uses Multi-wavelength meter
Calculate, have the characteristics that precision is high, exempt from correction, but instrument needs to use the devices such as pump, valve, flow cell, reagent bag, mixer mutual
Coordinate, there are volume is big, high energy consumption, need to regularly replace the shortcomings of reagent, while indicator may can also cause pH value of solution in itself
The change of value.Water pH value detection method based on sensitive membrane, have the advantages that it is reusable, without chemical reagent inject,
But the leakage of indicator can influence measurement result, while existing Single wavelength determination method has the shortcomings such as measurement accuracy is low.
The content of the invention
The present invention provides a kind of multi-wavelength measuring method based on sensitive membrane on-line checking water pH value, overcomes the prior art
The shortcomings that middle accuracy of detection is low, indicator leakage causes measurement result deviation.
The present invention provides a kind of detection method based on sensitive membrane on-line checking water pH value, comprises the following steps：
1) sensitive membrane is prepared；
2) the different buffer solution of pH value is configured, sensitive membrane prepared by step 1) is placed in buffer solution, measures and obtains
The absorption spectrum of the sensitive membrane of step 1) preparation is taken, and the alkali state maximum of sensitive membrane is obtained according to the absorption spectrum of the sensitive membrane
Absorbing wavelength λ1With acid-state maximum absorption wavelength λ2, obtain wavelength X1And λ2When corresponding absorbance A1、A2；
3) as buffer solution pH=11-13, the absorbance A of step 2) acquisition1、A2A is denoted as respectively1(I2-)、A2(I2-)；
As buffer solution pH=4-6, the absorbance A of step 2) acquisition1、A2A is denoted as respectively1(HI-)、A2(HI-)；Utilize formula
e1=ε1(HI–)/ε2(HI–)=A1(HI–)/A2(HI–),
e2=ε1(I2–)/ε2(HI–)=A1(I2–)/A2(HI–),
e3=ε2(I2–)/ε2(HI–)=A2(I2–)/A2(HI–),
Obtain molar absorption coefficient ratio e1、e2、e3；
4) sensitive membrane prepared by step 1) is respectively placed in the buffer solution of pH=6-11, obtains multigroup absorbance ratio
R, R=A1/A2；
5) basisThe molar absorption coefficient ratio e obtained using step 3)1、
e2、e3The multigroup absorbance ratio R obtained with step 4) prepares linear regression curves, obtain linear regression curves slope 1/n and
Intercept pKa；
6) sensitive membrane for obtaining step 1) immerses water body to be measured, obtains wavelength X1And λ2When corresponding absorbance
A1X、A2X, obtain the absorbance ratio R under conditions presentX, RX=A1X/A2X；
7) the molar absorption coefficient ratio e for obtaining step 3)1、e2、e3, slope 1/n and intercept pK that step 5) obtainsa,
The absorbance ratio R that step 6) obtainsXSubstitute into formulaObtain the pH value of water body to be measured.
Preferably, sensitive membrane is prepared by sol-gel process, specifically includes following steps：
A. distilled water, absolute ethyl alcohol, HCl, surfactant and ethyl orthosilicate are measured respectively, weigh pH sensitive agents,
It is stirred at room temperature after mixing to clarification；
B. sol solutions aging step a obtained 1 to 7 day；
C. by spin coating method or the stagnant czochralski method of leaching, the solution after the aging obtained using step b is on the glass sheet
Prepare gel mould；Before preparation, cleaning activation is carried out to glass sheet surface；
D. the glass-film of cleaning, drying sol-gel coating, obtains sensitive membrane.
Preferably, the absorption spectrum for measuring sensitive membrane specifically includes following steps：
E. the buffer solution that pH value is 5-12 is configured, and utilizes the correction of glass pH meter；
F., the glass-film that sol-gel prepared by step d coats is respectively placed in the buffer solution for accommodating different pH value
Cuvette in, measured using spectrophotometer or spectrometer, obtain sensitive membrane of the sensitive membrane under different pH condition
Spectrum；
G. according to the sensitive membrane spectrum, the alkali state maximum absorption wavelength λ for preparing sensitive membrane is obtained1With acid-state absorption maximum
Wavelength X2。
Preferably, measurement parameter is calculated using step 3) and specifically includes following steps：
I. sensitive membrane is immersed in the vessel for accommodating buffer solution, wherein preparing the sensitive examinations of pH used in the sensitive membrane
Agent is binary acid, buffer solution pH=12；Light source provides first, second and third road stabilized light source output, wherein first via stabilized light source
The wavelength of output is equal to the alkali state maximum absorption wavelength of the sensitive membrane, and the wavelength of the second road stabilized light source output is equal to described quick
Feel the acid-state maximum absorption wavelength of film, the wavelength of the 3rd road stabilized light source output is equal to reference wavelength；Reference light paths are calculated to correspond to
Light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA1、IB1、IC1；Calculate absorbance A1(I2–) and A2(I2–), wherein
Ii. sensitive membrane is immersed in the vessel for accommodating buffer solution, buffer solution pH=5；Light source offer first and second,
Three road stabilized light source outputs, the wavelength of first via stabilized light source output are equal to the alkali state maximum absorption wavelength of the sensitive membrane, the
The wavelength of two road stabilized light source outputs is equal to the acid-state maximum absorption wavelength of the sensitive membrane, the ripple of the 3rd road stabilized light source output
Length is equal to reference wavelength；Calculate reference light paths and correspond to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA2、IB2、IC2；Calculate
Absorbance A1(HI–) and A2(HI–), wherein
Iii. molar absorption coefficient ratio e is calculated1、e2、e3, wherein e1=A1(HI–)/A2(HI–), e2=A1(I2–)/A2
(HI–), e3=A2(I2–)/A2(HI–)；
Iv. absorbance ratio R is obtained；Sensitive membrane is immersed respectively in multiple vessel for accommodating buffer solution, wherein slow
Rush pH value of solution=6~11；Light source assembly provides first, second and third road stabilized light source output respectively, calculates multigroup reference light paths and corresponds to
Light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA、IB、IC；Calculate multigroup absorbance A1、A2, wherein Sensitive membrane is obtained in different pH
The absorbance ratio R, R=A being worth in buffer solution1/A2。
Detection method proposed by the invention, it is ensured that water body measures pH value and extinction in the pH value range with indicator discoloration
Spend in a linear relationship.The pH value of detection is only dependent upon detection water body absorbance ratio R to be measuredXThis single parameter, color developing agent are dense
Degree does not interfere with detected value, it is possible to prevente effectively from baseline drift caused by indicator leaks.
Invention also provides a kind of inspection based on sensitive membrane on-line checking water pH value using above-mentioned detection method
Survey device, including light source assembly, optical path component, signal acquisition component and control assembly；Further include and the contact of extraneous water body the
One seal cavity and the second seal cavity, and it is provided with the sensitive membrane of pH sensitive agents；Wherein, the light source assembly is arranged on
In the first annular seal space body, the stabilized light source for providing multiple wavelength exports；The optical path component includes and the stabilization
Optical filter, collector lens, photo-coupler, optical fiber and the optical window that light source output is correspondingly arranged；Wherein, the optical window bag
The first optical window and the second optical window are included, is respectively embedded in first annular seal space body and the correspondence side wall of the second seal cavity
On；The collector lens includes first collector lens and the second collector lens, the first collector lens and the second collector lens
It is separately positioned in first annular seal space body and the second seal cavity；The light that the light source assembly is sent is through optical filter, photo-coupler
After be divided into two parts, a part is measurement light, is injected successively after first collector lens, the first optical window, extraneous water body quick
Feel film；Light by the sensitive membrane directive signal acquisition component after the second optical window, the second collector lens successively；
Another part is reference light, the directive signal acquisition component after fiber optic conduction；The signal acquisition component is arranged on described second
In seal cavity, for carrying out opto-electronic conversion and exporting detection signal to control assembly；The control assembly is used to receive signal
Acquisition component output detects signal and in the pH value of line computation outside water body.
Further, the sensitive membrane is arranged between first annular seal space body and the second seal cavity and is fixed on described
On one optical window, the second optical window, quartz or glass.
Preferably, the wavelength for the first via stabilized light source output that the light source assembly provides is equal to the alkali state of the sensitive membrane
Maximum absorption wavelength, the wavelength of the second road stabilized light source output are equal to the acid-state maximum absorption wavelength of the sensitive membrane, the 3rd tunnel
The wavelength of stabilized light source output is equal to wavelength of the sensitive membrane entirely without absorption.
Preferably, the optical filter include the first narrow band pass filter corresponding with light source assembly, the second narrow band pass filter with
And the 3rd narrow band pass filter；The centre wavelength of wherein described first narrow band pass filter is equal to alkali state maximum absorption wavelength, and second is narrow
Centre wavelength with optical filter is equal to acid-state maximum absorption wavelength, and the centre wavelength of the 3rd narrow band pass filter is stablized equal to the 3rd tunnel
The centre wavelength of light source.
Preferably, the signal acquisition component includes photodiode, CCD and/or photomultiplier；The light source assembly
Including independently arranged LED light, laser and/or halogen lamp.
Preferably, the pH sensitive agents are phenol red, dimethyl diaminophenazine chloride, m-cresol purple or phenolphthalein.
Detection device provided by the present invention based on sensitive membrane on-line checking water pH value, the note without added regent
Enter, integrated level is high, small, energy consumption is low, it is reusable, be adapted to on-line checking.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is attached drawing needed in technology description to be briefly described, it should be apparent that, drawings in the following description are this hairs
Some bright embodiments, for those of ordinary skill in the art, without having to pay creative labor, can be with
Other attached drawings are obtained according to these attached drawings.
Fig. 1 is the detection device first using the method proposed by the invention based on sensitive membrane on-line checking water pH value
The structure diagram of embodiment；
Fig. 2 is the sensitive membrane spectrogram obtained in the present invention；
Fig. 3 is the regression curve schematic diagram prepared in the present invention.
Embodiment
To make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, the technical solution in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is
Part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art
All other embodiments obtained without creative efforts, belong to the scope of protection of the invention.
The present embodiment proposes that the basic principle of the method based on sensitive membrane on-line checking water pH value is as follows：With binary acid
PH sensitive agents (are denoted as H2I exemplified by), the pH value of its secondary ionization constant and water body to be measured approaches.When sensitive membrane is contacted with water body
When, the H that is fixed in the sensitive agents and water body in sensitive membrane+Generation reversible reaction, the HI of ionization generation acid-state–And alkali
The I of state2–.The ionization equilibrium can be written as：
It can thus be concluded that pH value is：
K in formulaaFor dissociation constant (Ka=[H+][I2-]/[HI-]), pKa=-log10(Ka)。
The HI of acid-state in water body–With the I of alkali state2–With different spectral signatures, its maximum absorption wavelength and molar absorptivity
Coefficient is different.When the sensitive membrane prepared using colloidal sol-gel method measures pH, thickness is about the absorbance that 1 μm of sensitive membrane obtains can
For 0.2-0.6, therefore absorbance does not strictly observe Bill-Lambert law with molar concentration.I.e. absorbance is not in molar concentration
Linear relationship, but have exponent relation.So absorbance calculation formula can be written as：
A1=ε1(HI-)[HI-]nl+ε1(I2-)[I2-]nl (3)
A2=ε2(HI-)[HI-]nl+ε2(I2-)[I2-]nl (4)
ε in formula1(HI-)、ε2(HI-)、ε1(I2-)、ε2(I2-), be respectively alkali state maximum absorption wavelength λ1With the maximum suction of acid-state
Receive wavelength X2When alkali state I2–, acid-state HI–Molar absorption coefficient, n is index coefficient, and l is optical path length, A1、A2It is divided into extinction
Degree.
It can be obtained by formula (3), (4)：
Make R=A1/A2, e1=ε1(HI–)/ε2(HI–), e2=ε1(I2–)/ε2(HI–), e3=ε2(I2–)/ε2(HI–), by formula
(2), (5) can obtain：
The timing of fixation form one of pH sensitive agents, measurement parameter (molar absorption coefficient ratio e in sensitive membrane1、e2、e3With
Index coefficient n) is constant.When measurement parameter determines, pH measured values are only related with absorbance ratio R.From formula (6),
PH and absorbance are in a linear relationship in the range of the pH of water body measurement and indicator discoloration.Absorbance ratio R is by pH sensitive agents
Middle alkali state I2–, acid-state HI–The decision of proportion, and it is unrelated with sensitive agents total amount fixed in sensitive membrane.Therefore, such a
Under the conditions of, pH meter calculation value is unrelated with the sensitive agents total amount of stationary state.
When pH value is relatively low, pH sensitive agents existence form is based on acid-state in sensitive membrane, [I at this time2–]+[HI–]≈
[HI–]；When pH value is higher, pH sensitive agents existence form is based on alkali state in sensitive membrane, [I at this time2–]+[HI–]≈[I2–].Cause
This, when the pH value of buffer solution is relatively low or higher, in wavelength X1And λ2Locate the absorbance A obtained1、A2A can be denoted as respectively1
(HI-)、A2(HI-)、A1(I2-)、A2(I2-).Since concentration is identical with optical path length, at this time：
e1=ε1(HI–)/ε2(HI–)=A1(HI–)/A2(HI–)
e2=ε1(I2–)/ε2(HI–)=A1(I2–)/A2(HI–)
e3=ε2(I2–)/ε2(HI–)=A2(I2–)/A2(HI–)
It can be calculated molar absorption coefficient ratio e1、e2、e3。
Further sensitive membrane is placed in the different buffer solution of pH value, then can measure sensitive membrane and delay in different pH value
Rush multigroup absorbance ratio R in solution.
According to molar absorption coefficient ratio e1、e2、e3With the absorbance ratio R obtained in different pH value buffer solutions, profit
Equation of linear regression can be obtained with formula (6).Measurement in formula (6) can be calculated to obtain using the slope and intercept of equation of linear regression
Parameter n and pKa.In this way, by measuring single parameter, that is, the absorbance ratio of water body to be measured can calculate water to be measured
The pH value of body.
Below by first embodiment to the detection side provided by the present invention based on sensitive membrane on-line checking water pH value
Method is described further.
Sensitive membrane is prepared first.Phenol red conduct pH sensitive agents are chosen, it is surfactant to choose Triton X-100.Amount
Take 5.0ml distilled water, 5.0ml absolute ethyl alcohols, the HCl of 3.0ml 0.1M, the positive silicic acid of 0.2ml Triton X-100 and 10.0ml
Ethyl ester (TEOS), it is phenol red to weigh 40mg, is stirred at room temperature after mixing to clarification.Used after the sol solution of preparation is aged for one day
In coating film on glass.
Sheet glass (3cm × 0.9cm × 1.1mm) is positioned over 2h in concentrated nitric acid, successively with distilled water and washes of absolute alcohol,
And dried under the conditions of 120 DEG C, the sheet glass of activation must be cleaned.Sheet glass after activation is placed on spin coater, table
Face instills the sol solutions after 200 μ L agings, and rotates 30s when rotating speed is 1900rpm.Sheet glass after coating is placed on 40 DEG C
After drying 48h in baking oven, successively using distilled water and washes of absolute alcohol, sensitive membrane is prepared.
Utilize 0.2M NaOAc, 0.3M HOAc, 0.2M Na2HPO4, 0.3M NaH2PO4, 0.05M Na2B4O7, 0.2M
H3BO3With 0.1M Na2CO3Configuration pH value is respectively 5-12 buffer solution.Buffer solution is corrected using glass pH meter, is utilized
0.1M HCl or 0.1M NaOH adjust buffer solution to required pH value.
The sensitive membrane that sol-gel coats is respectively placed in the cuvette containing different pH buffer, utilizes light splitting
Photometer or spectrometer measure, and obtain the spectrum of sensitive membrane during different pH value.It is shown in Figure 2, by the spectrum of sensitive membrane,
It can draw HI–And I2–Maximum absorption wavelength be divided into 445nm, 560nm.
First, second and third light source output stabilized light source exports, and LED light is preferably all, wherein the center of first, second and third light source
Wavelength respectively may be about 560nm, 445nm, 810nm.The wavelength of wherein first via stabilized light source output is equal to the alkali of the sensitive membrane
State maximum absorption wavelength, the wavelength of the second road stabilized light source output are equal to the acid-state maximum absorption wavelength of sensitive membrane, and the 3rd road is steady
The wavelength for determining light source output is equal to wavelength of the sensitive membrane entirely without absorption, i.e. reference source.
The method of the detection device on-line checking water pH value provided using the present embodiment, it is further comprising the steps of：
1) sensitive membrane is immersed in the vessel for accommodating buffer solution, buffer solution pH=12；First, second and third road light source
Stabilized light source output is provided, reference light paths is calculated and corresponds to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA1、IB1、IC1；Meter
Calculate absorbance A1(I2–) and A2(I2–), wherein
2) sensitive membrane is immersed in the vessel for accommodating buffer solution, buffer solution pH=5；First, second and third road light source carries
Exported for stabilized light source, calculate reference light paths and correspond to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA2、IB2、IC2；Calculate
Absorbance A1(HI–) and A2(HI–), wherein
3) molar absorption coefficient ratio e is calculated1、e2、e3, wherein e1=A1(HI–)/A2(HI–), e2=A1(I2–)/A2
(HI–), e3=A2(I2–)/A2(HI–).It can be calculated e1=0.0507, e2=1.501, e3=0.3687.
4) sensitive membrane is immersed respectively in multiple vessel for accommodating buffer solution, wherein buffer solution pH=6~11；Light
Source provides first, second and third road stabilized light source output respectively, calculates the reference that sensitive membrane is placed in each pH value buffer solution respectively
Light path corresponds to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA、IB、IC；Calculate multigroup absorbance A1、A2, whereinSensitive membrane is obtained in difference
Absorbance ratio R, R=A in pH value buffer solution1/A2.At least measure 5 to 6 group absorbance ratios.
5) basisUtilize molar absorption coefficient ratio e1、e2、e3Counted with step 4)
The multiple absorbance ratio R calculated prepare equation of linear regression：The slope and intercept of equation of linear regression are obtained, as shown in figure 3, its
Middle slope is equal to 1/n, and intercept is equal to pKa.It can be calculated n=1/2.5441=0.393, pKa=8.6116.
6) sensitive membrane is immersed in solution to be measured, light source provides first, second and third road stabilized light source output, calculates reference light
Road corresponds to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathAX、IBX、ICX；Calculate absorbance A1XAnd A2X, wherein
The absorbance A of water body to be measured is calculated1X=0.1812, A2X=0.2105, absorbance ratio R can be obtainedX=
0.8608。
7) by n=0.393, pKa=8.6116, e1=0.0507, e2=1.501, e3=0.3687, RX=0.8608 substitutes into
FormulaIt can be calculated pH value of solution=8.193 to be measured.The accuracy of detection of pH value can reach
To 0.001.
It is shown in Figure 1 be application it is proposed by the invention based on sensitive membrane on-line checking water pH value detection method one
The structure diagram of kind detection device, mainly including light source assembly, optical path component, signal acquisition component, control assembly and setting
There is the sensitive membrane of pH sensitive agents.H in water body+Reversible interaction is carried out with pH sensitive agents, surface color occurs
Change, so as to cause the change of sensitive membrane absorbance.When calculating pH value using this method and the device based on pH sensitive membranes, colour developing
The leakage of agent does not interfere with measurement result, and accuracy of detection is high, have reusable, small, electromagnetism interference performance strong and
The advantages that pollution-free.
Specifically, detection device includes 1 and second seal cavity 2 of first annular seal space body, first annular seal space body 1 and
The outer wall of two seal cavities 2 is contacted with extraneous water body.Light source assembly 4 is arranged in first annular seal space body 1, for providing multiple ripples
Long stabilized light source output, on-off circuit 3 control the switch of light source assembly 4.Optical path component includes corresponding with stabilized light source output
Optical filter 5, collector lens, photo-coupler 6, optical fiber 7 and the optical window of setting.Optical window includes 9 He of the first optical window
It is close that second optical window 11, the first optical window 9 and the second optical window 11 are correspondingly embedded in first annular seal space body 1 and second respectively
Seal in the side wall of cavity 2, the outer surface of the first optical window 9 and the second optical window 11 is contacted with extraneous water body.Collector lens
Including 8 and second collector lens 12 of first collector lens, first collector lens 8 are arranged in first annular seal space body 1, the second optically focused
Lens 12 are arranged in the second seal cavity 2.The light that light source assembly is sent is divided into two parts after optical filter 5, photo-coupler 6,
A part is measurement light, injects sensitive membrane 10 after first collector lens 8, the first optical window 9, extraneous water body successively；By
The light of the sensitive membrane 10 directive signal acquisition component 13 after the second optical window 11, the second collector lens 12 successively；It is another
Part is reference light, the directive signal acquisition component 13 after the conduction of optical fiber 7；Signal acquisition component 13 is arranged on the second seal cavity
In 2, for carrying out opto-electronic conversion output detection signal to control assembly 14.Control assembly 14 is used to receive signal acquisition component 13
Output detects signal and in the pH value of line computation outside water body.Signal acquisition component 13 is photo-electric conversion element, including photoelectricity
One or more in diode, CCD or photomultiplier.Control assembly 14 is processor or the list that can realize corresponding function
Piece machine or integrated circuit.
The sensitive agents used in sensitive membrane 10 are the one of which of phenol red, dimethyl diaminophenazine chloride, m-cresol purple or phenolphthalein, and use is molten
Glue-gel method prepares sensitive membrane.The method for preparing sensitive membrane 10 specifically includes：
A, measures 2-10ml distilled water, 2-10ml absolute ethyl alcohols, the HCl of 1-5ml 0.1M, 1-100mg sensitive agents, 0-
The surfactant of 0.5ml and the ethyl orthosilicate (TEOS) of 0-20ml, wherein surfactant can be cationic, anion
Type or medium-sized one of which.It is stirred at room temperature after each component is mixed to clarification.
B. sol solutions aging step a obtained 1 to 7 day.
C. by spin coating method or the stagnant czochralski method of leaching, the solution after the aging obtained using step b is on the glass sheet
Prepare gel mould；Before preparation, cleaning activation is carried out to glass sheet surface.
D. the glass-film of cleaning, drying sol-gel coating, obtains sensitive membrane.Glass-film is arranged on first annular seal space body
1 and second between seal cavity 2.Specifically, by glass-film be fixed on the first optical window 9 or the second optical window 11 with it is outer
In the one side or quartz, glass of boundary's water body contact.
To determine measurement parameter, it is necessary to obtain the spectrum of the sensitive membrane 10 of preparation.Prepare sensitive membrane spectrum specifically include with
Lower step：
E. the buffer solution that pH value is 5-12 is configured, utilizes glass pH meter correction buffer solution；
F. the glass-film that sol-gel coats is respectively placed in the cuvette for the buffer solution for accommodating different pH value,
Measured using spectrophotometer or spectrometer, obtain sensitive membrane spectrum of the sensitive membrane under different pH condition；
G. alkali state maximum absorption wavelength λ is obtained according to sensitive membrane spectrum1With acid-state maximum absorption wavelength λ2。
As shown in Figure 1, light source assembly includes three illuminating sources 41,42,43 to provide first, second and third tunnel stabilization respectively
Light source output.Illuminating source can be respectively LED light, laser and halogen lamp.First via stabilized light source exports and the second tunnel is stablized
Light source output is measurement light source, and the 3rd road stabilized light source output is reference source.The wavelength and λ of first via stabilized light source output1
It is close or equal, the wavelength and λ of the second road stabilized light source output2It is close or equal, the wavelength of the 3rd road stabilized light source output with
Sensitive membrane approaches or equal entirely without the wavelength of absorption.Corresponding, optical filter includes the first narrow band pass filter 51, the second arrowband is filtered
52 and the 3rd narrow band pass filter 53 of mating plate, wherein the centre wavelength and λ of the first narrow band pass filter 511It is close or equal, second
The centre wavelength and λ of narrow band pass filter 522Close or equal, light is stablized on centre wavelength and the 3rd tunnel of the 3rd narrow band pass filter 53
The centre wavelength in source approaches or equal.
When pH value is relatively low, [I2–]+[HI–]≈[HI–]；When pH value is higher, [I2–]+[HI–]≈[I2–].When therefore measuring,
Detection device is immersed in the vessel for accommodating buffer solution first, buffer solution pH=12.Three illuminating sources 41,42,43
Stabilized light source output, 13 acquisition testing signal output of signal acquisition component to control assembly 14 are provided, control assembly 14 calculates ginseng
Light intensity I is corresponded to than light pathA0、IB0、IC0Light intensity I is corresponded to optical pathA1、IB1、IC1；Calculate absorbance A1(I2–) and A2(I2–),
Wherein
Then detection device is immersed in the vessel for accommodating buffer solution, buffer solution pH=5；Light source assembly provides the
First, two, three road stabilized light source output, 13 acquisition testing signal output of signal acquisition component to control assembly 14, the control assembly
14 calculating reference light paths correspond to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA2、IB2、IC2；Calculate absorbance A1(HI–) and
A2(HI–), wherein
Control assembly 14 calculates molar absorption coefficient ratio e1、e2、e3, wherein e1=A1(HI–)/A2(HI–), e2=A1
(I2–)/A2(HI–), e3=A2(I2–)/A2(HI–)。
Calculate absorbance ratio R.Detection device is respectively enterd in multiple vessel for accommodating buffer solution.Buffer solution
PH=6~11.Light source assembly provides first, second and third road stabilized light source output respectively, and 13 acquisition testing signal of signal acquisition component is defeated
Go out to control assembly 14.Control assembly 14 calculates reference light paths and corresponds to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA、IB、
IC；Calculate absorbance A1、A2, wherein
Obtain multigroup absorbance ratio R, R=A of the sensitive membrane 10 in different pH value buffer solutions1/A2.5 to 6 group data are obtained to be preferred,
More multi-group data can also be obtained according to being actually needed.
Control assembly 14 is according to formula (6) and molar absorption coefficient ratio e1、e2、e3The multiple dulling luminosity ratios calculated with step 4
Value R prepares equation of linear regression.By e1、e2、e3And multiple absorbance ratios substitute into formula (6) and prepare regression curve one by one, obtain
Equation of linear regression L.The slope that control assembly 14 calculates regression equation is 1/n, intercept pKa。
After all measurement parameters are obtained, according to formulaDuring detection in external world's water body
Absorbance ratio R of the pH value only with sensitive membrane in water body to be measured it is related.Detection device is immersed in solution to be measured, light source group
Part provides first, second and third road stabilized light source output, 13 acquisition testing signal output of signal acquisition component to control assembly 14, control
Component 14 processed calculates reference light paths and corresponds to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathAX、IBX、ICX；Calculate absorbance A1X
And A2X, obtain the absorbance ratio R under conditions presentX, wherein According to e1、e2、e3With slope 1/n, intercept pKa, control assembly 14 can be online
Calculate and export the pH value of solution to be measured, wherein
The detection method and detection device based on sensitive membrane on-line checking water pH value that above-described embodiment is proposed, are based on
Sensitive membrane technology, without injecting added regent, device integrated level is high, small, energy consumption is low, easy to carry, may be reused,
Have the advantages that accuracy of detection is high, the degree of automation is high.The detection method proposed, in water body measurement and the pH of indicator discoloration
PH value and absorbance are in a linear relationship in the range of value.The pH value of detection is only dependent upon this single parameter of absorbance ratio R, colour developing
Agent concentration does not interfere with detected value, it is possible to prevente effectively from baseline drift caused by indicator leaks.
Finally it should be noted that：The above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although
The present invention is described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that：It still may be used
To modify to the technical solution described in foregoing embodiments, or equivalent substitution is carried out to which part technical characteristic；
And these modification or replace, do not make appropriate technical solution essence depart from various embodiments of the present invention technical solution spirit and
Scope.
Claims (9)
- A kind of 1. method based on sensitive membrane on-line checking water pH value, it is characterised in that comprise the following steps：1) sensitive membrane is prepared；2) the different buffer solution of pH value is configured, sensitive membrane prepared by step 1) is placed in buffer solution, measures and obtains step The absorption spectrum of the rapid sensitive membrane 1) prepared, and according to the alkali state absorption maximum of the absorption spectrum of sensitive membrane acquisition sensitive membrane Wavelength X1With acid-state maximum absorption wavelength λ2, obtain wavelength X1And λ2When corresponding absorbance A1、A2；3) as buffer solution pH=11-13, the absorbance A of step 2) acquisition1、A2A is denoted as respectively1(I2-)、A2(I2-)；As buffer solution pH=4-6, the absorbance A of step 2) acquisition1、A2It is denoted as respectivelyA1(HI-)、A2(HI-)；Utilize formulae1=ε1(HI–)/ε2(HI–)=A1(HI–)/A2(HI–),e2=ε1(I2–)/ε2(HI–)=A1(I2–)/A2(HI–),e3=ε2(I2–)/ε2(HI–)=A2(I2–)/A2(HI–),Obtain molar absorption coefficient ratio e1、e2、e3；4) sensitive membrane prepared by step 1) is respectively placed in the buffer solution of pH=6-11, obtains multigroup absorbance ratio R, R =A1/A2；5) basisThe molar absorption coefficient ratio e obtained using step 3)1、e2、e3With Multigroup absorbance ratio R that step 4) obtains prepares linear regression curves, obtains the slope 1/n and intercept of linear regression curves pKa；6) sensitive membrane for obtaining step 1) immerses water body to be measured, obtains wavelength X1And λ2When corresponding absorbance A1X、A2X, Obtain the absorbance ratio R under conditions presentX, RX=A1X/A2X；7) the molar absorption coefficient ratio e for obtaining step 3)1、e2、e3, slope 1/n and intercept pK that step 5) obtainsa, step 6) the absorbance ratio R obtainedXSubstitute into formulaObtain the pH value of water body to be measured；Wherein, the sensitive membrane is prepared by sol-gel process, specifically includes following steps：A. distilled water, absolute ethyl alcohol, HCl, surfactant and ethyl orthosilicate are measured respectively, weighs pH sensitive agents, are mixed After be stirred at room temperature to clarification；B. sol solutions aging step a obtained 1 to 7 day；C. prepared on the glass sheet by spin coating method or the stagnant czochralski method of leaching, the solution after the aging obtained using step b Gel mould；Before preparation, cleaning activation is carried out to glass sheet surface；D. the glass-film of cleaning, drying sol-gel coating, obtains sensitive membrane.
- 2. the method according to claim 1 based on sensitive membrane on-line checking water pH value, it is characterised in that measurement is sensitive The absorption spectrum of film specifically includes following steps：E. the buffer solution that pH value is 5-12 is configured, and utilizes the correction of glass pH meter；F. the sensitive membrane of preparation is respectively placed in the cuvette for the buffer solution for accommodating different pH value, utilizes spectrophotometer Or spectrometer measures, sensitive membrane spectrum of the sensitive membrane under different pH condition is obtained；G. the alkali state maximum absorption wavelength λ of the sensitive membrane prepared according to the sensitive membrane optical spectroscopy1With acid-state maximum absorption wavelength λ2。
- 3. the method according to claim 1 based on sensitive membrane on-line checking water pH value, it is characterised in that described in use It is specific further comprising the steps of when step 3) obtains measurement parameter：I. sensitive membrane is immersed and accommodated in the vessel of buffer solution, wherein preparing the pH sensitive agents used in the sensitive membrane and being Binary acid, buffer solution pH=12；Light source provides first, second and third road stabilized light source output, and wherein first via stabilized light source exports Wavelength be equal to the alkali state maximum absorption wavelength of the sensitive membrane, the wavelength of the second road stabilized light source output is equal to the sensitive membrane Acid-state maximum absorption wavelength, the wavelength of the 3rd road stabilized light source output is equal to reference wavelength；Calculate reference light paths and correspond to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA1、IB1、IC1；Calculate absorbance A1(I2–) and A2(I2–), whereinIi. sensitive membrane is immersed in the vessel for accommodating buffer solution, buffer solution pH=5；Light source provides first, second and third tunnel Stabilized light source exports, and the wavelength of first via stabilized light source output is equal to the alkali state maximum absorption wavelength of the sensitive membrane, the second tunnel The wavelength of stabilized light source output is equal to the acid-state maximum absorption wavelength of the sensitive membrane, the wavelength of the 3rd road stabilized light source output etc. In reference wavelength；Calculate reference light paths and correspond to light intensity IA0、IB0、IC0Light intensity I is corresponded to optical pathA2、IB2、IC2；Calculate extinction Spend A1(HI–) and A2(HI–), whereinIii. molar absorption coefficient ratio e is calculated1、e2、e3, wherein e1=A1(HI–)/A2(HI–), e2=A1(I2–)/A2(HI–), e3=A2(I2–)/A2(HI–)；Iv. absorbance ratio R is obtained；Sensitive membrane is immersed respectively in multiple vessel for accommodating buffer solution, wherein buffering molten Liquid pH=6~11；Light source provides first, second and third road stabilized light source output respectively, and the wavelength of first via stabilized light source output is equal to The alkali state maximum absorption wavelength of the sensitive membrane, the wavelength of the second road stabilized light source output are equal to the acid-state maximum of the sensitive membrane Absorbing wavelength, the wavelength of the 3rd road stabilized light source output are equal to reference wavelength；Calculate multigroup reference light paths and correspond to light intensity IA0、IB0、 IC0Light intensity I is corresponded to optical pathA、IB、IC；Calculate multigroup absorbance A1、A2, wherein Obtain sensitive Multigroup absorbance ratio R, R=A of the film in different pH value buffer solutions1/A2。
- It is 4. a kind of using such as detection of the claims 1 to 3 any one of them based on sensitive membrane on-line checking water pH value method Device, including light source assembly, optical path component, signal acquisition component and control assembly；It is characterized in that, further include and extraneous water body The first annular seal space body and the second seal cavity of contact, and it is provided with the sensitive membrane of pH sensitive agents；Wherein,The light source assembly is arranged in the first annular seal space body, and the stabilized light source for providing multiple wavelength exports；The optical path component includes optical filter, collector lens, photo-coupler, the optical fiber being correspondingly arranged with stabilized light source output And optical window；Wherein, the optical window includes the first optical window and the second optical window, is respectively embedded in the first sealing On cavity and the correspondence side wall of the second seal cavity；The collector lens includes first collector lens and the second collector lens, institute State first collector lens and the second collector lens is separately positioned in first annular seal space body and the second seal cavity；The light source group The light that part is sent is divided into two parts after optical filter, photo-coupler, and a part is measurement light, successively through first collector lens, the Sensitive membrane is injected after one optical window, extraneous water body；Light by the sensitive membrane is successively by the second optical window, second Directive signal acquisition component after collector lens；Another part is reference light, the directive signal acquisition component after fiber optic conduction；The signal acquisition component is arranged in second seal cavity, for carrying out opto-electronic conversion and exporting detection signal extremely Control assembly；The control assembly is used to receive the detection signal of signal acquisition component output and in the pH value of line computation outside water body.
- 5. detection device according to claim 4, it is characterised in that the sensitive membrane is arranged on first annular seal space body and Between two seal cavities and it is fixed on first optical window, the second optical window, quartz or glass.
- 6. detection device according to claim 5, it is characterised in that the first via stabilized light source that the light source assembly provides The wavelength of output is equal to the alkali state maximum absorption wavelength of the sensitive membrane, and the wavelength of the second road stabilized light source output is equal to described quick Feel the acid-state maximum absorption wavelength of film, the wavelength of the 3rd road stabilized light source output is equal to ripple of the sensitive membrane entirely without absorption It is long.
- 7. detection device according to claim 6, it is characterised in that the optical filter includes corresponding with light source assembly the One narrow band pass filter, the second narrow band pass filter and the 3rd narrow band pass filter；The middle cardiac wave of wherein described first narrow band pass filter Length is equal to alkali state maximum absorption wavelength, and the centre wavelength of the second narrow band pass filter is equal to acid-state maximum absorption wavelength, the 3rd arrowband The centre wavelength of optical filter is equal to the centre wavelength of the 3rd road stabilized light source.
- 8. detection device according to claim 7, it is characterised in that the signal acquisition component include photodiode, CCD and/or photomultiplier；The light source assembly includes independently arranged LED light, laser and/or halogen lamp.
- 9. according to claim 4 to 8 any one of them detection device, it is characterised in that the pH sensitive agents for it is phenol red, in The red, m-cresol purple of property or phenolphthalein.
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| CN107144540B (en) * | 2017-04-07 | 2020-01-17 | 哈尔滨工程大学 | Device for measuring KHP content in water by ultraviolet-visible light photometry |
| CN106932354B (en) * | 2017-05-16 | 2019-10-22 | 中国电子科技集团公司第四十九研究所 | A kind of TOC water quality monitoring sensor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5307146A (en) * | 1991-09-18 | 1994-04-26 | Iowa State University Research Foundation, Inc. | Dual-wavelength photometer and fiber optic sensor probe |
| CN101982760A (en) * | 2010-09-20 | 2011-03-02 | 北京邮电大学 | Optical fiber pH meter |
| CN102757576A (en) * | 2011-04-28 | 2012-10-31 | 昆山智集材料科技有限公司 | Production method of pH sensitive membranes |
| CN103091262A (en) * | 2011-11-04 | 2013-05-08 | 中国科学院电子学研究所 | Miniaturized optical device for detecting ammonia nitrogen in water and detecting method |
| CN103674867A (en) * | 2013-11-29 | 2014-03-26 | 中国科学院电子学研究所 | Method for detecting ammonia nitrogen concentration of water sample |
-
2016
- 2016-04-12 CN CN201610225483.4A patent/CN105675521B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5307146A (en) * | 1991-09-18 | 1994-04-26 | Iowa State University Research Foundation, Inc. | Dual-wavelength photometer and fiber optic sensor probe |
| CN101982760A (en) * | 2010-09-20 | 2011-03-02 | 北京邮电大学 | Optical fiber pH meter |
| CN102757576A (en) * | 2011-04-28 | 2012-10-31 | 昆山智集材料科技有限公司 | Production method of pH sensitive membranes |
| CN103091262A (en) * | 2011-11-04 | 2013-05-08 | 中国科学院电子学研究所 | Miniaturized optical device for detecting ammonia nitrogen in water and detecting method |
| CN103674867A (en) * | 2013-11-29 | 2014-03-26 | 中国科学院电子学研究所 | Method for detecting ammonia nitrogen concentration of water sample |
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