CN111208076A - Detection method for on-line determination of total chromium in water - Google Patents
Detection method for on-line determination of total chromium in water Download PDFInfo
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- 229910052804 chromium Inorganic materials 0.000 title claims abstract description 62
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- LGRFSURHDFAFJT-UHFFFAOYSA-N Phthalic anhydride Natural products C1=CC=C2C(=O)OC(=O)C2=C1 LGRFSURHDFAFJT-UHFFFAOYSA-N 0.000 claims description 10
- 239000004305 biphenyl Substances 0.000 claims description 10
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- JHIWVOJDXOSYLW-UHFFFAOYSA-N butyl 2,2-difluorocyclopropane-1-carboxylate Chemical compound CCCCOC(=O)C1CC1(F)F JHIWVOJDXOSYLW-UHFFFAOYSA-N 0.000 claims description 10
- -1 diphenyl carbodihydrazide Chemical compound 0.000 claims description 10
- 238000005259 measurement Methods 0.000 claims description 10
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N phenylbenzene Natural products C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 claims description 10
- 238000002360 preparation method Methods 0.000 claims description 10
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- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
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- 238000012360 testing method Methods 0.000 description 5
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 4
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- 238000012544 monitoring process Methods 0.000 description 4
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- 238000003321 atomic absorption spectrophotometry Methods 0.000 description 1
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- IMBKASBLAKCLEM-UHFFFAOYSA-L ferrous ammonium sulfate (anhydrous) Chemical compound [NH4+].[NH4+].[Fe+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O IMBKASBLAKCLEM-UHFFFAOYSA-L 0.000 description 1
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- 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
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/38—Diluting, dispersing or mixing samples
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
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Abstract
The invention relates to a method for detecting total chromium in water, in particular to a method for detecting total chromium in water on line, which comprises the steps of preparing an environment water sample to be detected, an environment water sample labeling solution to be detected and a series of total chromium ion standard solutions, putting the series of total chromium ion standard solutions into a water quality total chromium on-line monitor, respectively putting the environment water sample to be detected and the environment water sample labeling solution to be detected into the water quality total chromium on-line monitor according to a total chromium concentration-absorbance standard fitting curve obtained by a light source detection signal, measuring absorbance, and calculating to obtain the total chromium concentration according to the total chromium concentration-absorbance standard fitting curve; the technical scheme provided by the invention can effectively overcome the defects of complex operation, difficult maintenance and easy influence of the using amount of the oxidant and the color developing agent on the color developing result in the prior art.
Description
Technical Field
The invention relates to a method for detecting total chromium in water, in particular to a method for detecting total chromium in water on line.
Background
Chromium is a heavy metal with great toxicity, easily enters human cells, damages internal organs such as liver and kidney and DNA, deposits in human bodies and has carcinogenicity and may induce gene mutation. At present, the methods for analyzing and detecting total chromium in China include potassium permanganate oxidation-diphenylcarbazide spectrophotometry, ammonium ferrous sulfate titration, catalytic polarography, flame atomic absorption spectrophotometry, graphite furnace atomic absorption spectrometry and the like.
But the diphenyl carbodihydrazide spectrophotometry is widely applied in the field of water quality on-line monitoring because of the advantages of strong selectivity, high sensitivity, strong anti-interference performance, easy use and the like. The method for detecting total chromium by spectrophotometry in the field of water quality online monitoring mainly comprises the steps of using potassium permanganate or ammonium persulfate as an oxidizing agent, oxidizing trivalent chromium into hexavalent chromium under a heating condition, adding a color-developing agent diphenyl carbonyl Dihydrazide (DPC), and finally measuring data by spectrophotometry.
However, excessive oxidizing agent potassium permanganate or ammonium persulfate can affect color development, a reducing agent is needed to eliminate excessive oxidizing agent, for example, GB7466-1987 potassium permanganate is reduced by sodium nitrite, excessive sodium nitrite affects the test, substances such as urea and the like need to be added for removal, the steps are complicated to operate, the excessive oxidizing agent is not easy to remove, the secondary heating test period is needed, and the like is also needed for ammonium persulfate. In addition, the color reagent dibenzoyl dihydrazide is usually dissolved by ethanol or acetone, is easy to be oxidized and deteriorated, has short shelf life (usually one month), and can increase the maintenance amount when being applied to an online monitor.
In the "method for automatically monitoring total chromium in water on line" published under the number of CN102841088A, the absolute excess color reagent diphenylcarbodihydrazide is added to react with the oxidant potassium permanganate so as to eliminate the influence of the residual potassium permanganate on the measurement result. However, the method can cause the waste of the dibenzoyl dihydrazide, more dibenzoyl dihydrazide consumed by eliminating the oxidizing agent potassium permanganate is compared with the actual color development requirement, and because the total chromium in the water sample belongs to variables, the consumed potassium permanganate and the residual dibenzoyl dihydrazide can also change, so that the quantity of the color development agent is inconsistent during the color development reaction, the dynamic reaction of the color development system can be influenced, and the speed and the stability of the color development reaction can be influenced.
The CN103822883A publication No. of "method for monitoring total chromium in water" proposes that hydrogen peroxide is used as an oxidant, and the method does not need heating, but due to the low symmetry of the hydrogen peroxide molecular structure and the existence of peroxide bonds, the hydrogen peroxide is easy to self-decompose, has poor stability and short shelf life, and is not suitable for being applied to an on-line monitor.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects in the prior art, the invention provides a detection method for on-line determination of total chromium in water, which can effectively overcome the defects of complex operation, difficult maintenance and easy influence of the using amounts of an oxidant and a color developing agent on a color developing result in the prior art.
(II) technical scheme
In order to achieve the purpose, the invention is realized by the following technical scheme:
a detection method for online determination of total chromium in water comprises the following steps:
s1, preparing an environmental water sample to be detected, a standard solution for the environmental water sample to be detected and a series of total chromium ion standard solutions;
s2, putting a series of total chromium ion standard solutions into a water quality total chromium on-line monitor, and obtaining a total chromium concentration-absorbance standard fitting curve according to a light source detection signal;
and S3, respectively putting the to-be-detected environment water sample and the to-be-detected environment water sample adding standard solution into the water quality total chromium online monitor, measuring the absorbance, and calculating according to a total chromium concentration-absorbance standard fitting curve to obtain the total chromium concentration.
Preferably, formulating the series of total chromium ion standard solutions comprises: preparing 0.2mg/L, 0.4mg/L, 1mg/L, 2mg/L and 4mg/L of total chromium ion standard solution by using 100mg/L of mother solution respectively.
Preferably, preparing the environmental water sample to be detected comprises: the retrieved water sample was allowed to stand overnight and the supernatant was taken.
Preferably, the preparing the environmental water sample labeling solution to be detected comprises: 1ml of total chromium ion standard solution with the concentration of 1000mg/L is added into a 1L volumetric flask, and then the volume is fixed to 1L by using an environmental water sample to be measured.
Preferably, before the to-be-detected environmental water sample, the to-be-detected environmental water sample labeling solution and the series of total chromium ion standard solutions are placed into the water quality total chromium online monitor, an oxidant, a buffering agent and a color developing agent are sequentially added.
Preferably, the adding amounts of the to-be-detected environment water sample, the to-be-detected environment water sample labeling solution and the series of total chromium ion standard solutions are all 3.7mL, and the pH value is 6-9; adding 1.8mL of the oxidant, heating the mixture in a closed chamber at a constant temperature of 60 ℃ for 15min after adding the oxidant, and cooling the mixture to room temperature; 1.4mL of the buffer is added; and adding 1.8mL of the color developing agent, adding the color developing agent, shaking up, and standing for 5 min.
Preferably, the formulation of the oxidizing agent comprises: accurately weighing 0.2g of analytically pure potassium permanganate, dissolving in a certain amount of water, and then transferring to a volumetric flask to reach a constant volume of 1L.
Preferably, the formulation of the buffer comprises the steps of:
s1, accurately measuring 16.6ml of concentrated sulfuric acid and 16.6ml of phosphoric acid, adding the concentrated sulfuric acid and the 16.6ml of phosphoric acid into 400ml of water, and cooling for later use;
s2, accurately measuring 330ml of concentrated hydrochloric acid, adding the concentrated hydrochloric acid into the S1 prepared solution, and then transferring the solution into a 1L volumetric flask for constant volume.
Preferably, the formulation of the developer comprises the following steps:
s1, accurately measuring 500ml of absolute ethyl alcohol, and adding the absolute ethyl alcohol into a beaker;
s2, accurately weighing 5g of phthalic anhydride, adding the phthalic anhydride into the S1 prepared solution, and stirring until the phthalic anhydride is completely dissolved for later use;
s3, accurately weighing 0.3g of diphenyl carbodihydrazide, adding the diphenyl carbodihydrazide into the S2 preparation solution, and stirring until the diphenyl carbodihydrazide is completely dissolved for later use;
s4, accurately measuring 5ml of acetic acid, adding the acetic acid into the S3 prepared solution, uniformly stirring, and pouring the reagent into a brown bottle.
Preferably, the measurement of the absorbance of the environmental water sample to be measured, the environmental water sample labeling solution to be measured and the series of total chromium ion standard solutions requires colorimetric measurement under a light source with a wavelength of 540 nm.
(III) advantageous effects
Compared with the prior art, the detection method for on-line determination of total chromium in water provided by the invention has the following beneficial effects:
1. the method comprises the steps of utilizing a sample to carry out high-temperature digestion in a neutral environment through an oxidant, oxidizing trivalent chromium into hexavalent chromium, then adding a buffering agent and a color developing agent, enabling the color developing agent to react with the hexavalent chromium in an acid environment to generate a mauve complex, measuring absorbance under a light source of 540nm, reducing excessive potassium permanganate in the color developing process by hydrochloric acid in the buffering agent, enabling excessive hydrochloric acid not to influence dibenzoyl dihydrazide and the hexavalent chromium to generate the mauve complex, not interfering a background signal value, simply and quickly removing the influence of excessive potassium permanganate by adding the excessive hydrochloric acid, eliminating the influence of the oxidant without adding other reagents or adopting a secondary heating method, and enabling the whole measuring process to be simple and convenient;
2. the phthalic anhydride and the acetic acid are added during the preparation of the color developing agent, so that the color developing agent can play a role of a stabilizer, the effective period of the color developing agent can reach three months under the condition of light-proof storage, meanwhile, the quality guarantee periods of the oxidizing agent potassium permanganate and the buffering agent used in the invention can reach more than six months, the frequency of reagent replacement is reduced, the maintenance work is reduced, the quality guarantee period of the reagent is long, the detection result is reliable, and the method can be more conveniently applied to an online monitor.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a diagram of a standard fit curve of total chromium concentration-absorbance according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A detection method for online determination of total chromium in water comprises the following steps:
s1, preparing an environmental water sample to be detected, a standard solution for the environmental water sample to be detected and a series of total chromium ion standard solutions;
s2, putting a series of total chromium ion standard solutions into a water quality total chromium on-line monitor, and obtaining a total chromium concentration-absorbance standard fitting curve according to a light source detection signal;
and S3, respectively putting the to-be-detected environment water sample and the to-be-detected environment water sample adding standard solution into the water quality total chromium online monitor, measuring the absorbance, and calculating according to a total chromium concentration-absorbance standard fitting curve to obtain the total chromium concentration.
Preparing a series of total chromium ion standard solutions comprises: preparing 0.2mg/L, 0.4mg/L, 1mg/L, 2mg/L and 4mg/L of total chromium ion standard solution by using 100mg/L of mother solution respectively.
Preparing an environmental water sample to be detected comprises the following steps: the retrieved water sample was allowed to stand overnight and the supernatant was taken.
The method for preparing the environmental water sample adding standard solution to be detected comprises the following steps: 1ml of total chromium ion standard solution with the concentration of 1000mg/L is added into a 1L volumetric flask, and then the volume is fixed to 1L by using an environmental water sample to be measured.
Before an environmental water sample to be detected, an environmental water sample labeling solution to be detected and a series of total chromium ion standard solutions are placed in a water quality total chromium online monitor, an oxidant, a buffering agent and a color developing agent are required to be added in sequence.
The adding amount of the to-be-detected environment water sample, the to-be-detected environment water sample labeling solution and the series of total chromium ion standard solutions is 3.7mL, and the pH value is 6-9; adding 1.8mL of oxidant, heating in a closed chamber at a constant temperature of 60 ℃ for 15min after adding the oxidant, and cooling to room temperature; 1.4mL of buffer is added; adding 1.8mL of color developing agent, adding the color developing agent, shaking uniformly and standing for 5 min.
The preparation of the oxidant comprises the following steps: accurately weighing 0.2g of analytically pure potassium permanganate, dissolving in a certain amount of water, and then transferring to a volumetric flask to reach a constant volume of 1L.
The preparation of the buffering agent comprises the following steps:
s1, accurately measuring 16.6ml of concentrated sulfuric acid and 16.6ml of phosphoric acid, adding the concentrated sulfuric acid and the 16.6ml of phosphoric acid into 400ml of water, and cooling for later use;
s2, accurately measuring 330ml of concentrated hydrochloric acid, adding the concentrated hydrochloric acid into the S1 prepared solution, and then transferring the solution into a 1L volumetric flask for constant volume.
The preparation of the color developing agent comprises the following steps:
s1, accurately measuring 500ml of absolute ethyl alcohol, and adding the absolute ethyl alcohol into a beaker;
s2, accurately weighing 5g of phthalic anhydride, adding the phthalic anhydride into the S1 prepared solution, and stirring until the phthalic anhydride is completely dissolved for later use;
s3, accurately weighing 0.3g of diphenyl carbodihydrazide, adding the diphenyl carbodihydrazide into the S2 preparation solution, and stirring until the diphenyl carbodihydrazide is completely dissolved for later use;
s4, accurately measuring 5ml of acetic acid, adding the acetic acid into the S3 prepared solution, uniformly stirring, and pouring the reagent into a brown bottle.
The measured absorbance of the environmental water sample to be measured, the environmental water sample labeling solution to be measured and a series of total chromium ion standard solutions needs to be subjected to colorimetric measurement under a light source with the wavelength of 540 nm.
The method for measuring the total chromium concentration-absorbance standard fitting curve comprises the following steps:
respectively taking 3.7mL of total chromium ion standard solutions with the concentrations of 0.2mg/L, 0.4mg/L, 1mg/L, 2mg/L and 4mg/L, adding 1.8mL of an oxidizing agent, heating at 60 ℃ for oxidation reaction for 15min, then cooling to room temperature, adding 1.4mL of a buffering agent and 1.8mL of a color developing agent, shaking uniformly, standing for reaction for 5min, carrying out colorimetric measurement under a light source with the wavelength of 540nm, and obtaining a total chromium concentration-absorbance standard fitting curve according to a light source detection signal, wherein the total chromium ion standard solution is shown in figure 1 and table 1.
TABLE 1 relationship of Total chromium concentration to Absorbance
The method for determining the total chromium concentration in the environmental water sample to be detected and the added standard solution of the environmental water sample to be detected comprises the following steps:
respectively taking an environmental water sample to be detected and an environmental water sample to be detected, adding 3.7mL of standard solution, adding 1.8mL of oxidant, heating at 60 ℃ for oxidation reaction for 15min, then cooling to room temperature, adding 1.4mL of buffering agent and 1.8mL of developer, shaking uniformly, standing for reaction for 5min, carrying out colorimetric measurement under a light source with the wavelength of 540nm to obtain absorbance, calculating the total chromium concentration according to a total chromium concentration-absorbance standard fitting curve, and obtaining a measurement result shown in table 2.
TABLE 2 test results of environmental water sample to be tested and environmental water sample to be tested added with standard solution
The repeatability test method is as follows:
respectively taking 6 parts of total chromium standard solution (1.0mg/L) and an environmental water sample to be detected, and respectively marking as follows: a1, A2, A3, A4, A5, A6, B1, B2, B3, B4, B5 and B6 are respectively added with an oxidizing agent and mixed, then the mixture is heated and oxidized in a closed environment for digestion, the mixture is cooled to normal temperature after the oxidative digestion is completed, a buffering agent is added, then a color developing agent is added, the mixture is bubbled and uniformly mixed, the mixture is kept still for reaction for 5min, colorimetric measurement is carried out at the wavelength of 540nm to obtain absorbance, the total chromium concentration is calculated according to a total chromium concentration-absorbance standard fitting curve, and the measurement results are respectively shown in tables 3 and 4.
TABLE 3 Total chromium standard solution repeatability test results
Table 4 repeatability test results of environmental water sample to be tested
It is worth noting that the pH value of the environment water sample to be detected, the environment water sample labeling solution to be detected and a series of total chromium ion standard solutions is required to be between 6 and 9, so that the pH value of the reaction system is ensured to be between 6 and 9, namely a neutral environment, during the high-temperature digestion reaction after the oxidant is added, and the reaction system is in a strong acid environment during the color development.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.
Claims (10)
1. A detection method for online determination of total chromium in water is characterized by comprising the following steps: the method comprises the following steps:
s1, preparing an environmental water sample to be detected, a standard solution for the environmental water sample to be detected and a series of total chromium ion standard solutions;
s2, putting a series of total chromium ion standard solutions into a water quality total chromium on-line monitor, and obtaining a total chromium concentration-absorbance standard fitting curve according to a light source detection signal;
and S3, respectively putting the to-be-detected environment water sample and the to-be-detected environment water sample adding standard solution into the water quality total chromium online monitor, measuring the absorbance, and calculating according to a total chromium concentration-absorbance standard fitting curve to obtain the total chromium concentration.
2. The detection method for the on-line determination of the total chromium in the water according to claim 1, characterized in that: preparing the series of total chromium ion standard solutions comprises: preparing 0.2mg/L, 0.4mg/L, 1mg/L, 2mg/L and 4mg/L of total chromium ion standard solution by using 100mg/L of mother solution respectively.
3. The detection method for the on-line determination of the total chromium in the water according to claim 1, characterized in that: preparing the environmental water sample to be detected comprises the following steps: the retrieved water sample was allowed to stand overnight and the supernatant was taken.
4. The detection method for the on-line determination of the total chromium in the water according to claim 1, characterized in that: preparing the environment water sample adding solution to be detected comprises the following steps: 1ml of total chromium ion standard solution with the concentration of 1000mg/L is added into a 1L volumetric flask, and then the volume is fixed to 1L by using an environmental water sample to be measured.
5. The detection method for the on-line determination of the total chromium in the water according to claim 1, characterized in that: before the to-be-detected environment water sample, the to-be-detected environment water sample labeling solution and a series of total chromium ion standard solutions are placed into the water quality total chromium on-line monitor, an oxidant, a buffering agent and a color developing agent are required to be added in sequence.
6. The detection method for the on-line determination of the total chromium in the water according to claim 5, characterized in that: the adding amounts of the to-be-detected environment water sample, the to-be-detected environment water sample labeling solution and the series of total chromium ion standard solutions are all 3.7mL, and the pH value is 6-9; adding 1.8mL of the oxidant, heating the mixture in a closed chamber at a constant temperature of 60 ℃ for 15min after adding the oxidant, and cooling the mixture to room temperature; 1.4mL of the buffer is added; and adding 1.8mL of the color developing agent, adding the color developing agent, shaking up, and standing for 5 min.
7. The detection method for the on-line determination of the total chromium in the water according to claim 6, characterized in that: the preparation of the oxidant comprises the following steps: accurately weighing 0.2g of analytically pure potassium permanganate, dissolving in a certain amount of water, and then transferring to a volumetric flask to reach a constant volume of 1L.
8. The detection method for the on-line determination of the total chromium in the water according to claim 6, characterized in that: the preparation of the buffering agent comprises the following steps:
s1, accurately measuring 16.6ml of concentrated sulfuric acid and 16.6ml of phosphoric acid, adding the concentrated sulfuric acid and the 16.6ml of phosphoric acid into 400ml of water, and cooling for later use;
s2, accurately measuring 330ml of concentrated hydrochloric acid, adding the concentrated hydrochloric acid into the S1 prepared solution, and then transferring the solution into a 1L volumetric flask for constant volume.
9. The detection method for the on-line determination of the total chromium in the water according to claim 6, characterized in that: the preparation of the color developing agent comprises the following steps:
s1, accurately measuring 500ml of absolute ethyl alcohol, and adding the absolute ethyl alcohol into a beaker;
s2, accurately weighing 5g of phthalic anhydride, adding the phthalic anhydride into the S1 prepared solution, and stirring until the phthalic anhydride is completely dissolved for later use;
s3, accurately weighing 0.3g of diphenyl carbodihydrazide, adding the diphenyl carbodihydrazide into the S2 preparation solution, and stirring until the diphenyl carbodihydrazide is completely dissolved for later use;
s4, accurately measuring 5ml of acetic acid, adding the acetic acid into the S3 prepared solution, uniformly stirring, and pouring the reagent into a brown bottle.
10. The detection method for the on-line determination of the total chromium in the water according to claim 1, characterized in that: and measuring the absorbance of the to-be-measured environment water sample, the to-be-measured environment water sample labeling solution and a series of total chromium ion standard solutions by colorimetric measurement under a light source with the wavelength of 540 nm.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111678876A (en) * | 2020-07-21 | 2020-09-18 | 福州大学 | Quick detection method for hexavalent chromium in water environment based on machine learning |
| CN111707660A (en) * | 2020-06-23 | 2020-09-25 | 中国科学院城市环境研究所 | Method for rapidly and quantitatively detecting content of hexavalent chromium ions |
| CN112557315A (en) * | 2020-11-18 | 2021-03-26 | 上海仪电科学仪器股份有限公司 | Method for measuring calcium ion content |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10332672A (en) * | 1997-05-30 | 1998-12-18 | Kurita Seizosho:Kk | Measuring method for hexavalent chromium |
| JP2006322922A (en) * | 2005-04-19 | 2006-11-30 | Rst Project:Kk | Chromium detecting reagent |
| JP2007333555A (en) * | 2006-06-15 | 2007-12-27 | Mitsubishi Electric Corp | Hexavalent chromium detection method |
| JP2014016277A (en) * | 2012-07-10 | 2014-01-30 | Dkk Toa Corp | Chromium measurement reagent and chromium measurement method |
| CN104833672A (en) * | 2015-01-24 | 2015-08-12 | 四川久环环境技术有限责任公司 | Method of on-line monitoring total chromium in water with potassium chlorate as oxidant |
| CN104977205A (en) * | 2014-04-10 | 2015-10-14 | 鞍钢股份有限公司 | Leaching solution and detection method used for detecting content of hexavalent chromium on surface of cold-rolled sheet |
| CN105424686A (en) * | 2015-11-10 | 2016-03-23 | 广东环凯微生物科技有限公司 | Rapid total chromium concentration detecting reagent and method |
| CN107655881A (en) * | 2017-09-06 | 2018-02-02 | 安徽英凯环境技术有限公司 | A kind of high-precision water quality online automatic monitor |
| CN107843585A (en) * | 2017-11-22 | 2018-03-27 | 安徽皖仪科技股份有限公司 | The novel detection method of total chrome content in a kind of environmental water sample of anti-various metals ion interference |
| CN110346355A (en) * | 2019-06-28 | 2019-10-18 | 安徽皖仪科技股份有限公司 | A kind of method of the total zinc of online automatic detection of anti-various metals ion interference |
-
2020
- 2020-01-19 CN CN202010062813.9A patent/CN111208076A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10332672A (en) * | 1997-05-30 | 1998-12-18 | Kurita Seizosho:Kk | Measuring method for hexavalent chromium |
| JP2006322922A (en) * | 2005-04-19 | 2006-11-30 | Rst Project:Kk | Chromium detecting reagent |
| JP2007333555A (en) * | 2006-06-15 | 2007-12-27 | Mitsubishi Electric Corp | Hexavalent chromium detection method |
| JP2014016277A (en) * | 2012-07-10 | 2014-01-30 | Dkk Toa Corp | Chromium measurement reagent and chromium measurement method |
| CN104977205A (en) * | 2014-04-10 | 2015-10-14 | 鞍钢股份有限公司 | Leaching solution and detection method used for detecting content of hexavalent chromium on surface of cold-rolled sheet |
| CN104833672A (en) * | 2015-01-24 | 2015-08-12 | 四川久环环境技术有限责任公司 | Method of on-line monitoring total chromium in water with potassium chlorate as oxidant |
| CN105424686A (en) * | 2015-11-10 | 2016-03-23 | 广东环凯微生物科技有限公司 | Rapid total chromium concentration detecting reagent and method |
| CN107655881A (en) * | 2017-09-06 | 2018-02-02 | 安徽英凯环境技术有限公司 | A kind of high-precision water quality online automatic monitor |
| CN107843585A (en) * | 2017-11-22 | 2018-03-27 | 安徽皖仪科技股份有限公司 | The novel detection method of total chrome content in a kind of environmental water sample of anti-various metals ion interference |
| CN110346355A (en) * | 2019-06-28 | 2019-10-18 | 安徽皖仪科技股份有限公司 | A kind of method of the total zinc of online automatic detection of anti-various metals ion interference |
Non-Patent Citations (1)
| Title |
|---|
| 韦美栋: "浅析水中的总铬测定" * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111707660A (en) * | 2020-06-23 | 2020-09-25 | 中国科学院城市环境研究所 | Method for rapidly and quantitatively detecting content of hexavalent chromium ions |
| CN111707660B (en) * | 2020-06-23 | 2023-02-10 | 中国科学院城市环境研究所 | Method for rapidly and quantitatively detecting content of hexavalent chromium ions |
| CN111678876A (en) * | 2020-07-21 | 2020-09-18 | 福州大学 | Quick detection method for hexavalent chromium in water environment based on machine learning |
| CN112557315A (en) * | 2020-11-18 | 2021-03-26 | 上海仪电科学仪器股份有限公司 | Method for measuring calcium ion content |
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