CN113702365A - Method for measuring content of ferric ions in aqueous solution - Google Patents
Method for measuring content of ferric ions in aqueous solution Download PDFInfo
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- CN113702365A CN113702365A CN202110848113.7A CN202110848113A CN113702365A CN 113702365 A CN113702365 A CN 113702365A CN 202110848113 A CN202110848113 A CN 202110848113A CN 113702365 A CN113702365 A CN 113702365A
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- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 229910001447 ferric ion Inorganic materials 0.000 title claims abstract description 44
- 239000007864 aqueous solution Substances 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 23
- ABBQHOQBGMUPJH-UHFFFAOYSA-M Sodium salicylate Chemical compound [Na+].OC1=CC=CC=C1C([O-])=O ABBQHOQBGMUPJH-UHFFFAOYSA-M 0.000 claims abstract description 31
- 229960004025 sodium salicylate Drugs 0.000 claims abstract description 31
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910052742 iron Inorganic materials 0.000 claims abstract description 23
- 239000000243 solution Substances 0.000 claims abstract description 23
- -1 iron ion Chemical class 0.000 claims abstract description 20
- 238000010521 absorption reaction Methods 0.000 claims abstract description 18
- 238000000862 absorption spectrum Methods 0.000 claims abstract description 17
- 238000005259 measurement Methods 0.000 claims abstract description 15
- 238000011088 calibration curve Methods 0.000 claims abstract description 14
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 claims abstract description 10
- 229910000360 iron(III) sulfate Inorganic materials 0.000 claims abstract description 10
- 239000011259 mixed solution Substances 0.000 claims abstract description 10
- 239000000203 mixture Substances 0.000 claims description 8
- 239000010453 quartz Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- 230000003595 spectral effect Effects 0.000 claims description 3
- 230000003287 optical effect Effects 0.000 claims description 2
- YGSDEFSMJLZEOE-UHFFFAOYSA-N salicylic acid Chemical compound OC(=O)C1=CC=CC=C1O YGSDEFSMJLZEOE-UHFFFAOYSA-N 0.000 abstract description 10
- FJKROLUGYXJWQN-UHFFFAOYSA-N papa-hydroxy-benzoic acid Natural products OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 abstract description 5
- 229960004889 salicylic acid Drugs 0.000 abstract description 5
- 229910052751 metal Inorganic materials 0.000 abstract description 2
- 239000002351 wastewater Substances 0.000 description 3
- 239000010842 industrial wastewater Substances 0.000 description 2
- 239000012086 standard solution Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- FHXGZTHZFMMNCP-UHFFFAOYSA-N 2-hydroxybenzoic acid;iron Chemical compound [Fe].OC(=O)C1=CC=CC=C1O FHXGZTHZFMMNCP-UHFFFAOYSA-N 0.000 description 1
- 241000143060 Americamysis bahia Species 0.000 description 1
- 241000282414 Homo sapiens Species 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
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- 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
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
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- 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
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- 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
- G01N21/33—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using ultraviolet light
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- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
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- Plasma & Fusion (AREA)
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- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
Abstract
A method for measuring the content of ferric ions in an aqueous solution relates to the field of quantitative determination of metal elements. The method comprises the following steps: 1) drawing a ferric ion content calibration curve: preparing a sodium salicylate solution, mixing ferric sulfate aqueous solutions with different concentrations with the sodium salicylate solution in equal volume, measuring an ultraviolet-visible absorption spectrum of the mixed solution, and drawing an iron ion concentration measurement calibration curve; 2) measuring the concentration of ferric ions in the aqueous solution sample: and mixing the sodium salicylate with the known concentration and the aqueous solution sample to be measured in an equal volume, and measuring the absorption spectrum of the mixed solution to obtain the concentration of ferric ions in the aqueous solution sample. Salicylic acid and ferric ions form a complex in an aqueous solution, and the absorption spectrum of the complex has an absorption peak at about 524 nm. Under the condition of a certain concentration of sodium salicylate, the absorption peak intensity of the complex at 524nm is in direct proportion to the concentration of ferric ions, so that the method can be used for quantitatively determining the concentration of the ferric ions.
Description
Technical Field
The invention relates to the field of quantitative determination of metal elements, in particular to a method for determining the content of ferric ions in an aqueous solution.
Background
When the iron ion content in the iron-containing wastewater discharged from the industry exceeds a certain value, the direct discharge of the iron-containing wastewater into the natural environment can bring about great negative effects, so that the ecological environment is destroyed. In the past, the heavy metal content of fishes and shrimps in rivers and plants in fields exceeds the standard, and the living aspects of human beings are further influenced. Whether the concentration of iron ions in the industrial wastewater reaches the discharge standard or not is one of important detection items in the industrial wastewater treatment. Besides industrial discharge waste water, drinking water, and domestic water, it is also important to determine the content of iron ions. How to accurately measure the concentration of the iron ions by using a simple and quick method is very important.
Disclosure of Invention
The invention aims to provide a method for measuring the content of ferric ions in an aqueous solution, which can simply, conveniently and quickly measure the concentration of the ferric ions.
The invention comprises the following steps:
1) drawing a ferric ion content calibration curve: preparing a sodium salicylate solution, mixing ferric sulfate aqueous solutions with different concentrations with the sodium salicylate solution in equal volume, measuring an ultraviolet-visible absorption spectrum of the mixed solution, and drawing an iron ion concentration measurement calibration curve;
2) measuring the concentration of ferric ions in the aqueous solution sample: and mixing the sodium salicylate with the known concentration and the aqueous solution sample to be measured in an equal volume, and measuring the absorption spectrum of the mixed solution to obtain the concentration of ferric ions in the aqueous solution sample.
In step 1), the concentration of the sodium salicylate solution is 1.0mM (the concentration of the sodium salicylate solution can adopt other values, but the coefficient of the calibration curve can be changed correspondingly); the concentration of the ferric sulfate aqueous solution with different concentrations needs to be less than 1.2 mM.
In step 1), the specific steps of drawing the calibration curve of the ferric ion content may be:
firstly, preparing a sodium salicylate solution with a certain concentration, and then mixing ferric sulfate aqueous solutions with different concentrations with the prepared sodium salicylate solution in an equal volume; measuring the ultraviolet visible absorption spectrum of the mixed solution, and drawing to obtain an iron ion concentration measurement calibration curve by taking the iron ion concentration as a horizontal axis and the absorption peak intensity at 524nm as a vertical axisLine, the absorption peak intensity I at 524nm is obtained by line fitting524nmWith concentration of ferric ion CFe3+The linear relation (1):
where K is a linear coefficient and C is a constant related to the spectral baseline position.
In step 2), the specific steps for measuring the concentration of ferric ions in the aqueous solution sample may be: the method comprises the steps of uniformly mixing an isovolumetric water solution sample to be detected containing ferric ions and a sodium salicylate solution with a certain concentration of 1.0mM, placing the mixture into a quartz cuvette with a light path of 10mM after color development, measuring an ultraviolet and visible absorption spectrum of the mixture, and taking the absorption peak intensity at 524nm of the mixture to calculate the concentration of the ferric ions in the sample according to a relational expression (1) (the light path of the cuvette for measuring the concentration of the solution needs to be consistent with a measurement standard curve. in the embodiment of the invention, the standard curve measurement adopts the quartz cuvette with the light path of 10mM, and the cuvettes with other light paths, and if the cuvettes with other light paths are adopted, different fitting curves are obtained).
The principle of the invention is as follows: salicylic acid and ferric ions form a complex in an aqueous solution, and the absorption spectrum of the complex has an absorption peak at about 524 nm. Under the condition of a certain concentration of sodium salicylate, the absorption peak intensity of the complex at 524nm is in direct proportion to the concentration of ferric ions, so that the method can be used for quantitatively determining the concentration of the ferric ions. The method utilizes the complexing principle to measure the concentration of the ferric iron in the solution, and has the advantages of rapid measurement, high accuracy and simple operation.
Drawings
FIG. 1 is an absorption spectrum of an aqueous solution of ferric sodium salicylate ion when sodium salicylate was used at a concentration of 1.0 mM. The curves show, from bottom to top, 0.2mM, 0.4mM, 0.6mM, 0.8mM, 1.0mM, 1.2mM, 1.6mM, 2.0mM, 3.0mM, 4.0mM, 5.0mM, and 6.0mM, respectively.
FIG. 2 is a graph showing the relationship between the absorption intensity of salicylic acid-iron ion complex at 524nm and the concentration of iron ion when sodium salicylate was used at a concentration of 1.0 mM.
FIG. 3 is an absorption spectrum of sodium salicylate aqueous solutions of various concentrations when the iron ion concentration was 2.0 mM. The curves show, from bottom to top, 0.1mM, 0.2mM, 0.3mM, 0.4mM, 0.5mM, 0.6mM, 0.8mM, 1.0mM, 1.5mM, and 2.0mM, respectively.
FIG. 4 is a graph showing the relationship between the absorption intensity of salicylic acid-iron complex at 524nm and the concentration of iron ion when the concentration of iron ion was 2.0 mM.
Detailed Description
The following examples will further illustrate the present invention with reference to the accompanying drawings.
The embodiment of the invention comprises the following steps:
drawing a ferric ion content calibration curve: firstly, preparing a certain amount of sodium salicylate solution, and then mixing ferric sulfate aqueous solutions with different concentrations with the prepared sodium salicylate solution in equal volume. Measuring the ultraviolet visible absorption spectrum of the mixed solution, drawing to obtain an iron ion concentration measurement calibration curve by taking the iron ion concentration as a horizontal axis and the absorption peak intensity at 524nm as a vertical axis, and obtaining the absorption peak intensity I at 524nm by linear fitting524nmWith concentration of ferric ion CFe3+Where K is a linear coefficient and C is a constant related to the spectral baseline position.
Measurement of ferric ion concentration in sample: and mixing the sodium salicylate with the known concentration and the sample to be detected in equal volume, measuring the absorption spectrum of the mixed solution, taking the absorption peak intensity at 524nm, and calculating the concentration of ferric ions in the sample according to the relation (1).
The specific measurement steps are as follows:
and (3) drawing a calibration curve: 1mL of ferric sulfate standard solution with different concentrations and 1mL of sodium salicylate solution with the concentration of 1.0mM are taken in sequence and mixed uniformly, after developing color for 2 minutes, the mixture is placed into a quartz cuvette with the optical path of 10mM, and the ultraviolet visible absorption spectrum of the mixture is measured (figure 1). By taking the absorption intensity at 524nm of the spectrum in FIG. 1 as a graph of the absorption intensity-iron ion concentration (FIG. 2), a line fitting can be obtained:
then
And (3) measuring the concentration of iron ions: ferric sulfate standard solutions with different concentrations are prepared and measured by the method, and as shown in table 1, the measurement result is very close to the actual value, so that the method can be used as a simple means for measuring the concentration of ferric ions.
In the 10mM light path method given below, the ferric ion concentration can be measured in the range of 0mM to 1.2mM, and if the measurement range is to be increased, one method is to reduce the light path of the cuvette because the coefficient K is inversely proportional to the light path of the cuvette according to beer-lambert's law (if a cuvette with other light path is used, a different fitted curve will be obtained). Another method is to reduce the concentration of the sodium salicylate solution and find that the absorption intensity of ferric ion and salicylic acid complex is directly proportional to the concentration of the sodium salicylate solution (fig. 3 and 4), so that the measurement range of the ferric ion concentration can be increased by reducing the concentration of sodium salicylate.
TABLE 1 results of iron ion concentration measurement using salicylic acid method
The invention is described above with reference to examples, but the invention is not limited to the examples and should cover the examples as well as modified equivalent combinations of different concentrations of iron ion salicylic acid.
Claims (5)
1. A method for measuring the content of ferric ions in an aqueous solution is characterized by comprising the following steps:
1) drawing a ferric ion content calibration curve: preparing a sodium salicylate solution, mixing ferric sulfate aqueous solutions with different concentrations with the sodium salicylate solution in equal volume, measuring an ultraviolet-visible absorption spectrum of the mixed solution, and drawing an iron ion concentration measurement calibration curve;
2) measuring the concentration of ferric ions in the aqueous solution sample: and mixing the sodium salicylate with the known concentration and the aqueous solution sample to be measured in an equal volume, and measuring the absorption spectrum of the mixed solution to obtain the concentration of ferric ions in the aqueous solution sample.
2. The method according to claim 1, wherein in the step 1), the concentration of the sodium salicylate solution is 1.0 mM.
3. The method according to claim 1, wherein in step 1), the concentration of ferric ions in the ferric sulfate aqueous solutions with different concentrations is less than 1.2 mM.
4. The method for determining the content of ferric ions in the aqueous solution according to claim 1, wherein in the step 1), the specific step of drawing the calibration curve of the content of ferric ions is as follows:
firstly, preparing a sodium salicylate solution with a certain concentration, and then mixing ferric sulfate aqueous solutions with different concentrations with the prepared sodium salicylate solution in an equal volume; measuring the ultraviolet visible absorption spectrum of the mixed solution, drawing to obtain an iron ion concentration measurement calibration curve by taking the iron ion concentration as a horizontal axis and the absorption peak intensity at 524nm as a vertical axis, and obtaining the absorption peak intensity I at 524nm by linear fitting524nmWith concentration of ferric ion CFe3+The linear relation (1):
where K is a linear coefficient and C is a constant related to the spectral baseline position.
5. The method for determining the content of ferric ions in the aqueous solution according to claim 1, wherein in the step 2), the specific steps for measuring the concentration of ferric ions in the aqueous solution sample are as follows:
the method comprises the steps of uniformly mixing an isovolumetric aqueous solution sample to be detected containing ferric ions with a sodium salicylate solution with the concentration of 1.0mM, placing the mixture into a quartz cuvette with the optical path of 10mM after color development, measuring the ultraviolet visible absorption spectrum of the mixture, taking the absorption peak intensity at 524nm of the mixture, and calculating the concentration of the ferric ions in the sample according to the linear relation (1).
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Citations (5)
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|---|---|---|---|---|
| CN102323228A (en) * | 2011-06-22 | 2012-01-18 | 恒正科技（苏州）有限公司 | The assay method of ferrous iron and ferric iron content in the lithium iron phosphate cathode material |
| CN102519894A (en) * | 2011-12-21 | 2012-06-27 | 陕西省石油化工研究设计院 | Ferric ion stabilizing capability measurement method of acidification ferric ion stabilizer |
| CN102621090A (en) * | 2012-04-12 | 2012-08-01 | 厦门大学 | Method for measuring iron content in kaolin through using spectrophotometer |
| RU2011144136A (en) * | 2011-10-31 | 2013-05-10 | Государственное бюджетное образовательное учреждение высшего профессионального образования "Амурская государственная медицинская академия" Минздравсоцразвития Российской Федерации | METHOD FOR QUANTITATIVE DETERMINATION OF IRON IONS |
| CN105467070A (en) * | 2015-12-31 | 2016-04-06 | 攀枝花东方钛业有限公司 | Method for quick measurement of ferric ion content in sulfate process titanium dioxide decomposing titanium liquor |
-
2021
- 2021-07-27 CN CN202110848113.7A patent/CN113702365A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102323228A (en) * | 2011-06-22 | 2012-01-18 | 恒正科技（苏州）有限公司 | The assay method of ferrous iron and ferric iron content in the lithium iron phosphate cathode material |
| RU2011144136A (en) * | 2011-10-31 | 2013-05-10 | Государственное бюджетное образовательное учреждение высшего профессионального образования "Амурская государственная медицинская академия" Минздравсоцразвития Российской Федерации | METHOD FOR QUANTITATIVE DETERMINATION OF IRON IONS |
| CN102519894A (en) * | 2011-12-21 | 2012-06-27 | 陕西省石油化工研究设计院 | Ferric ion stabilizing capability measurement method of acidification ferric ion stabilizer |
| CN102621090A (en) * | 2012-04-12 | 2012-08-01 | 厦门大学 | Method for measuring iron content in kaolin through using spectrophotometer |
| CN105467070A (en) * | 2015-12-31 | 2016-04-06 | 攀枝花东方钛业有限公司 | Method for quick measurement of ferric ion content in sulfate process titanium dioxide decomposing titanium liquor |
Non-Patent Citations (1)
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