CN109725106A - A kind of method of phosphorus content in measurement aluminum electrolytic capacitor electrode foil - Google Patents
A kind of method of phosphorus content in measurement aluminum electrolytic capacitor electrode foil Download PDFInfo
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- CN109725106A CN109725106A CN201711019775.3A CN201711019775A CN109725106A CN 109725106 A CN109725106 A CN 109725106A CN 201711019775 A CN201711019775 A CN 201711019775A CN 109725106 A CN109725106 A CN 109725106A
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- electrode foil
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Abstract
The present invention provides a kind of method for measuring phosphorus content in aluminum electrolytic capacitor electrode foil, comprising the following steps: (1) electrode foil sample is carried out micro-wave digestion, obtain test solution a；(2) test solution a is subjected to ion exchange, obtains test solution b；(3) test solution b is subjected to alkali formula titration determination phosphorus content.Wherein, micro-wave digestion pre-treating method enables electrode foil sample fast decoupled；The cation exchange column of strong-acid type carries out ion exchange, to remove the interference metal ion in test solution；The method measurement of alkali formula titration does not need to use large-scale detection device, is avoided that detection device Matrix effects.The present invention measures the phosphorus content in aluminum electrolytic capacitor electrode foil using the method that micro-wave digestion is combined with the titration of alkali formula, can not only fast and accurately obtain analysis as a result, and measurement result error is small, stability is good, reproducibility is high, accuracy.
Description
Technical field
The present invention relates to a kind of method of phosphorus content in measurement aluminum electrolytic capacitor electrode foil more particularly to a kind of use are micro-
The method of phosphorus content in wave resolution-alkali formula titration determination aluminum electrolytic capacitor electrode foil.
Background technique
It needs to be melted into electrode foil in the manufacturing process of aluminium electrolutic capacitor, electrode foil chemical conversion is former using electrochemistry
Reason, electrode foil paillon is aoxidized, makes the oxygen in forming liquid in conjunction with aluminium, generates fine and close oxide film dielectric layer.Electrode foil
When middle phosphorus content is exceeded, it will be unable to form firm oxidation film, so that generating excessive free acid, free acid in capacitor product
Established still unstable oxidation film can be dissolved, leakage current is caused to increase, so far will seriously affect the performance of capacitor product.
Since electrode foil is one of the important raw material of aluminium electrolytic capacitor product, accurate detection, monitoring phosphorus content provide excellent
The high performance electrode foil of matter is the big important indicator for ensureing aluminium electrolytic capacitor product excellent properties.
In electrode foil in existing detection aluminium electrolutic capacitor the method for the content of phosphorus be will be in aluminium electrolutic capacitor
The dissolution of electrode foil sample, then uses inductively coupled plasma emission spectrography (Inductively Coupled Plasma
Optical Emission Spectrometry, ICP-OES) detection solution in phosphorus content.But this analysis method is led at present
There are following several respects defects: first, there are the spectrum spectral peak interference between other elements, matrix using ICP-OES test
P elements can be interfered；Second, ICP-OES instrument price is higher, disposably put into larger, when work needs to consume a large amount of
Argon gas, running expense are high；Third, ICP-OES instrumental sensitivity is not high enough, detection limit is too high so that testing precision is low, failure
Rate is high.
Therefore, it is necessary to develop, a kind of result is interference-free, aluminium electroloysis easy to operate and not depending on large-scale detection device
The measuring method of phosphorus content in capacitor electrode foil.
Summary of the invention
It is an object of the invention to propose that a kind of combine by micro-wave digestion-alkali formula titration measures aluminium electrolutic capacitor electricity
The method of phosphorus content in the foil of pole has low Monitoring lower-cut, accuracy and precision height, method simplicity, operation fast using this method
The features such as fast.
To achieve this purpose, the present invention adopts the following technical scheme:
The present invention provides a kind of method for measuring phosphorus content in aluminum electrolytic capacitor electrode foil, comprising the following steps:
(1) electrode foil sample is subjected to micro-wave digestion, obtains test solution a；
(2) test solution a is subjected to ion exchange, obtains test solution b；
(3) test solution b is subjected to alkali formula titration determination phosphorus content.
Wherein, in step (1), the micro-wave digestion includes: that electrode foil sample is placed in counteracting tank, and resolution is added
Liquid, then counteracting tank is placed in micro-wave digestion equipment and carries out micro-wave digestion according to default resolution program.The micro-wave digestion is
The phosphorus in aluminum electrolytic capacitor electrode foil is set to form H in acid condition by way of pressurized, heated airtight microwave digestion3PO4。
Further, the digestion solution includes water, concentrated hydrochloric acid, concentrated nitric acid and the concentrated sulfuric acid.
Further, in the digestion solution, with volume basis, water: concentrated hydrochloric acid: concentrated nitric acid: concentrated sulfuric acid 2:2:3:2.
Further, the micro-wave digestion equipment is microwave dissolver, specifically, the microwave dissolver is Austria's peace
Eastern pa Multiwave PRO super-pressure microwave dissolver.
Further, the default resolution program is power 1200W, and temperature programming 15min, program keeps the temperature 75min, cooling
20min, 235 DEG C of temperature, pressure 55bar.
Correspondingly, in step (2), the ion exchange includes: then to lead to the test solution after constant volume first by test solution a constant volume
Cross cation exchange column.Can remove in test solution a by ion exchange may interfere in the process subsequent titration determination
Metal ion.
Further, the constant volume is that test solution a is transferred in volumetric flask, is added water to volumetric flask graduation mark.
Further, the cation exchange column is the cation exchange column of strong-acid type.
Correspondingly, in step (3), the alkali formula titration includes:
(i) methyl orange indicator is added in test solution b first, is titrated to methyl orange indicator with sodium hydroxide solution and becomes
Color；
(ii) hydrochloric acid solution is then added, heating is boiled, and is added methyl orange indicator after cooling, is dripped with sodium hydroxide solution
Determine to methyl orange indicator to change colour；
(iii) it is eventually adding phenolphthalein indicator, phenolphthalein indicator discoloration is titrated to sodium hydroxide solution, writes down hydroxide
Sodium solution usage amount.
Further, the methyl orange indicator concentration is 1g/L.Specifically, the methyl orange indicator color change interval is
PH3.1~pH 4.7.Specifically, the methyl orange indicator discoloration is that red becomes yellow.
Further, the preparation method of the methyl orange indicator is to weigh 0.1g methyl orange to add ultrapure water 100mL, heating
Dissolution, cooled and filtered are shaken.
Further, the phenolphthalein indicator concentration is 10g/L.Specifically, the phenolphthalein indicator color change interval is pH
8.3~pH 10.0.Specifically, the phenolphthalein indicator discoloration becomes red to be colourless.
Further, the preparation method of the phenolphthalein indicator is to take 1g phenolphthalein, is dissolved in ethyl alcohol, is diluted to ethyl alcohol
100mL.Preferably, without adding water in the preparation process of phenolphthalein indicator.
Further, the concentration of the hydrochloric acid solution is 0.1mol/L.
Further, the preparation method of the hydrochloric acid solution is to take concentrated hydrochloric acid 9mL with graduated cylinder correct amount, pours into and fills in advance
In the beaker of suitable quantity of water, it is transferred in 1000mL volumetric flask, is diluted with water to graduation mark, shake up.
Further, the concentration of the sodium hydroxide solution is 0.15mol/L.
Further, the preparation method of the sodium hydroxide solution is to weigh 6g sodium hydroxide in the volumetric flask of 1L, is used
It is shaken up after water dissolution.The Potassium Hydrogen Phthalate 0.8g dried is accurately weighed in 400mL beaker, is dissolved with 150mL boiling water,
It is cooled to room temperature, 6~7 0.1% phenolphthalein of drop is added, being titrated to red with sodium hydroxide solution is terminal, calculates sodium hydroxide solution
Molar concentration.The molar concentration for calculating sodium hydroxide solution can be obtained by following formula:
In formula: C is the molar concentration of sodium hydroxide solution, mol/L；
V is the volume of sodium hydroxide solution, mL；
M is the molal weight of Potassium Hydrogen Phthalate, g/mol；
M is the quality for weighing Potassium Hydrogen Phthalate, g.
Specifically, step (i) is to make H in test solution a3PO4It is titrated to H2PO4 -, using sodium hydroxide solution in acid medium
Direct titration, to eliminate the interference that strong acid coexists, it is ensured that measurement result is more acurrate.PH is 4.67 at this time, is referred to using methyl orange work
Show agent.It relates generally to react at this time are as follows:
Further, step (ii) is to make H3PO4It is fully converted to H2PO4 -, it has been neutralized with ensuring to coexist strong acid.
Further, step (iii) is to make H in test solution a2PO4 ˉIt is titrated to HPO4 2ˉ, pH is 9.67 at this time, is made using phenolphthalein
Indicator.It relates generally to react at this time are as follows:
Containing for the phosphorus in test solution can be calculated according to the amount of the sodium hydroxide solution of titration consumption in step (iii) as a result,
Amount, i.e., the phosphorus content in aluminum electrolytic capacitor electrode foil can be calculated according to following formula:
In formula: P is the phosphorus content in test solution, %；
V is the volume that phenolphthalein post consumption sodium hydroxide is added, mL；
C is the concentration of sodium hydroxide standard liquid, mol/L；
M is the molal weight of phosphorus, g/mol；
M is the quality for weighing sample, g.
The invention has the benefit that
1, the present invention is measured in aluminum electrolytic capacitor electrode foil using the method that micro-wave digestion is combined with the titration of alkali formula
Phosphorus content, can not only fast and accurately obtain analysis as a result, and measurement result error is small, stability is good, reproducibility
High, accuracy.
2, the present invention uses micro-wave digestion pre-treating method, enables electrode foil sample fast decoupled, when reducing measurement
Between, improve determination efficiency.
3, the present invention is that test solution is passed through strong-acid type using the foreign ion in ion-exchange removal test solution
Cation exchange column carries out ion exchange, to remove the interference metal ion in test solution, it is ensured that measurement result is more acurrate.
4, the present invention is not needed to use large-scale detection device, is avoided that detection device using the method measurement of alkali formula titration
Matrix effects, and can realize automation and METHOD FOR CONTINUOUS DETERMINATION.
5, for the present invention using the method measurement of alkali formula titration, Monitoring lower-cut is low, method is easy, operation is rapid, can reduce
Labor intensity, saving analysis time, investment is small, effect is good, the reality high particularly suitable for sample arbitration and precision, accuracy requirement
Test room use.
Specific embodiment
To keep the technical problems solved, the adopted technical scheme and the technical effect achieved by the invention clearer, below
Technical solution of the present invention will be described in further detail in conjunction with the embodiments, it is clear that described embodiment is only this
Invention a part of the embodiment, instead of all the embodiments.
Test device therefor: Austrian Anton Paar Multiwave PRO super-pressure microwave dissolver；U.S.'s Agilent 720
Series inductance coupled plasma-atomic emission spectrometer.
Test agents useful for same: methyl orange (excellent pure grade)；Phenolphthalein (excellent pure grade)；Sodium hydroxide (excellent pure grade)；Phthalic acid
Hydrogen potassium (excellent pure grade)；Concentrated hydrochloric acid (analysis is pure)；Concentrated nitric acid (analysis is pure)；The concentrated sulfuric acid (analysis is pure).
Embodiment one
Preparation of reagents:
1g/L methyl orange indicator: weighing 0.1g methyl orange and add ultrapure water 100mL, dissolves by heating, and cooled and filtered is shaken
?.
10g/L phenolphthalein indicator: taking 1g phenolphthalein, be dissolved in ethyl alcohol, is diluted to 100mL with ethyl alcohol, without adding water.
0.1mol/L hydrochloric acid solution is prepared and calibration: taking concentrated hydrochloric acid 9mL with graduated cylinder correct amount, pours into and fill suitable quantity of water in advance
Beaker in, be transferred in 1000mL volumetric flask, be diluted with water to graduation mark, shake up.
The sodium hydroxide solution of 0.15mol/L is prepared and calibration: weighing 6g sodium hydroxide in the volumetric flask of 1L, use is water-soluble
It is shaken up after solution.The Potassium Hydrogen Phthalate 0.8g dried is accurately weighed, in 400mL beaker, is dissolved with 150mL boiling water, it is cold
To room temperature, 6~7 0.1% phenolphthalein of drop are added, being titrated to red with sodium hydroxide solution is terminal, calculates hydroxide by formula 1
The molar concentration of sodium solution.
Embodiment two
The determination step of phosphorus content in aluminum electrolytic capacitor electrode foil:
Micro-wave digestion: aluminum electrolytic capacitor electrode foil sample is cut into fractionlet with the ceramic scissors that alcohol rinse is crossed, is claimed
It takes 0.1g as sample, is placed in counteracting tank, sequentially add 2mL ultrapure water, 3mL concentrated hydrochloric acid, 3mL concentrated nitric acid and the 2mL concentrated sulfuric acid；
It is placed on microwave turntable after micro-wave diminishing pot external application porcelain bushing is fixed, then according to the resolution program of aluminium oxide as Austria
It is cleared up 2 hours or so in land productivity Anton Paar Multiwave PRO super-pressure microwave dissolver, setting resolution program are as follows: power
1200W, temperature programming 15min, program keep the temperature 75min, and cooling 20min, 235 DEG C of temperature, pressure 55bar obtains test solution a.
Ion exchange: after test solution a is cooling, being added about 10mL water, transfer in 100mL volumetric flask, clear with ultrapure water
Scale is washed and be settled to, the test solution a after constant volume is obtained into test solution b by the cation exchange column of strong-acid type after shaking up.
The titration of alkali formula: it in test solution b plus after 5~6 drop methyl orange indicators, is dripped with the sodium hydroxide solution of 0.15mol/L
It is fixed extremely to change colour.Then the hydrochloric acid solution 10mL of 0.1mol/L is added, heating is boiled, is removed, and it is cooling, add methyl orange indicator
5~6 drops, then discoloration is titrated to 0.15mol/L sodium hydroxide solution.Again plus phenolphthalein indicator 10~12 drips, and uses 0.15mol/L
It is terminal that sodium hydroxide solution, which drops to red, writes down the amount of the sodium hydroxide solution of consumption.
The phosphorus content in test solution is calculated by formula 2.
The preparation of methyl orange indicator used, phenolphthalein indicator, hydrochloric acid solution, sodium hydroxide solution is the same as real in the present embodiment
Apply example one.
According to the present embodiment step operation, five batches of aluminum electrolytic capacitor electrode foil samples of parallel analysis, the measurement of sample
The results are shown in Table 1:
The measurement result of 1 five batches of parallel samples of table
By the parallel sample measurement result in table 1 it is found that five batches of aluminium electricity being measured in parallel using test method of the invention
Electrolysis condenser electrode foil sample repeatability RSD is 0.44%, shows that the result fluctuation of test method measurement of the invention is small, stablizes
Property is good.
Embodiment three
It is accurate to measure 10mL blank acid sample, the phosphorus standard solution of 0.05ppm is added, through the invention in alkali formula titrate step
Phosphorus content in rapid measurement sample, measurement result 0.05ppm.
Comparative example one
It is accurate to measure 10mL blank acid sample, the phosphorus standard solution of 0.05ppm is added, is measured in sample by ICP-OES
The determination condition of phosphorus content, the ICP-OES is conventional determining condition, and any wavelength of measurement result P elements is without feature diffraction
Phosphorus element content is not detected in peak, illustrate that this method can not Accurate Determining 0.05ppm standard phosphorus content sample.
By the measurement result of embodiment three and comparative example one it is found that for concentration be 0.05ppm sample, ICP-OES without
Method detects definitive result, and can measure sample concentration using the alkali formula titration step in the present invention, and since ICP-OES is examined
The determination limit of measurement equipment is 1.0ppm, the sample lower than 1.0ppm concentration cannot be measured by ICP-OES method, but can
With alkali formula titration step measurement through the invention, i.e., test method Monitoring lower-cut of the invention is lower than ICP-OES method.
Claims (9)
1. a kind of method of phosphorus content in measurement aluminum electrolytic capacitor electrode foil, which comprises the following steps:
(1) electrode foil sample is subjected to micro-wave digestion, obtains test solution a；
(2) test solution a is subjected to ion exchange, obtains test solution b；
(3) test solution b is subjected to alkali formula titration determination phosphorus content.
2. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 1, which is characterized in that in step
Suddenly in (1), the micro-wave digestion includes: that electrode foil sample is placed in counteracting tank, digestion solution is added, then counteracting tank is placed
Micro-wave digestion is carried out according to default resolution program in micro-wave digestion equipment.
3. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 2, which is characterized in that described
Digestion solution includes water, concentrated hydrochloric acid, concentrated nitric acid and the concentrated sulfuric acid.
4. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 3, which is characterized in that described
In digestion solution, with volume basis, water: concentrated hydrochloric acid: concentrated nitric acid: concentrated sulfuric acid 2:2:3:2.
5. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 2, which is characterized in that described
Default resolution program is power 1200W, temperature programming 15min, and program keeps the temperature 75min, cooling 20min, 235 DEG C of temperature, pressure
55bar。
6. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 1, which is characterized in that in step
Suddenly in (2), the ion exchange include: first by test solution a constant volume, it is described then by the test solution after constant volume by cation exchange column
Cation exchange column is the cation exchange column of strong-acid type.
7. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 1, which is characterized in that in step
Suddenly in (3), the alkali formula titration includes:
(i) methyl orange indicator is added in test solution b first, is titrated to methyl orange indicator discoloration with sodium hydroxide solution；
(ii) hydrochloric acid solution is then added, heating is boiled, and is added methyl orange indicator after cooling, is titrated to sodium hydroxide solution
Methyl orange indicator discoloration；
(iii) it is eventually adding phenolphthalein indicator, phenolphthalein indicator discoloration is titrated to sodium hydroxide solution, it is molten to write down sodium hydroxide
Liquid usage amount.
8. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 7, which is characterized in that described
Methyl orange indicator concentration is 1g/L, and the phenolphthalein indicator concentration is 10g/L.
9. the method for phosphorus content in measurement aluminum electrolytic capacitor electrode foil according to claim 7, which is characterized in that described
The concentration of hydrochloric acid solution is 0.1mol/L, and the concentration of the sodium hydroxide solution is 0.15mol/L.
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| CN110057967A (en) * | 2019-05-27 | 2019-07-26 | 南通海星电子股份有限公司 | Aluminum ions quantitative detecting method in a kind of aluminum electric pole foil corrosive liquid |
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Application publication date: 20190507 |