CN1210557C - Test piece for detecting hexavalent chromium and preparing method thereof - Google Patents
Test piece for detecting hexavalent chromium and preparing method thereof Download PDFInfo
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- CN1210557C CN1210557C CN 02145465 CN02145465A CN1210557C CN 1210557 C CN1210557 C CN 1210557C CN 02145465 CN02145465 CN 02145465 CN 02145465 A CN02145465 A CN 02145465A CN 1210557 C CN1210557 C CN 1210557C
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Abstract
The present invention discloses a test piece for detecting hexavalent chromium. The test piece comprises a water-absorbing material, diphenylcarbazide, a surface active agent and a stabilizing agent, wherein the water-absorbing material is used as a carrier, and the diphenylcarbazide is used as a color-developing agent. The present invention also discloses a method for preparing the test piece, which comprises: a solution A containing the surface active agent, the stabilizing agent and an arbitrary masking agent is prepared; a solution B containing the color-developing agent and an arbitrary acidity modifying agent is prepared; the water-absorbing material is immersed in the solution A and is taken out to be dried; the water-absorbing material immersed by the solution A is immersed in the solution B and is taken out to be dried. The test piece can detect the content of hexavalent chromium in a short time, and the error is in the range of semi-quantitative analysis. The test piece has the advantages of simple and convenient use and operation, high stability and strong anti-interference ability, and the test piece is particularly suitable for rapid detection on site.
Description
Technical field
The present invention relates to be used to detect the preparation method of chromic test block and this test block.
Background technology
Chromium is one of trace element of needed by human.The toxicity of chromium is relevant with the valence state of its existence.It has been generally acknowledged that sexavalent chrome exceeds 100 times than chromic toxicity.Sexavalent chrome has pungency to skin, can make skin ulcer, has been confirmed to be carcinogen, and can put aside for absorption of human body and in human body.The source of chromium mainly is an industrial waste water, and therefore chromic mensuration becomes one of conventional project of ambient water quality detection.In addition, sexavalent chrome easily is reduced and can be adsorbed on the vessel surface, therefore is preferably the employing on-site measurement.
National standard method (National Standard Method) adopts diphenyl carbazide spectrophotometry to measure sexavalent chrome, carries out instrumental analysis with spectrophotometer in water colour developing carrier.The precision height of this method, but need well-trained professional and technical personnel in the laboratory, to measure, and need to use expensive analytical instrument, the test duration is more than 30 minutes, so be not suitable for on-site measurement.
Chinese invention patent application 91106876.7 has disclosed the method for a kind of ion plastic monitoring card and rapid monitoring six-valence Cr thereof in (publication number CN 1062211A, open day on June 24th, 1992).It is carrier that ion plastic monitoring card adopts the polyfoam that carries out activation processing through inorganic acid solution and organic solvent and plastifier, surfactant, is developer with the diphenylcarbazide.Monitoring chromic method with ion plastic monitoring card is that water sampling adds perchloric acid, shake up the back dropping liquid on ion plastic monitoring card, compare with the standard colour code colour developing back, reads chromic concentration in the water sample, need use the tool plug in this method than pipe and adjustable miropipettor (or glass capillary).Carrying to the scene detection of these instruments and perchloric acid reagent brings inconvenience, and this method still has certain requirement for operating personnel.
Summary of the invention
An object of the present invention is to provide a kind of test block that is used for detecting quickly and easily content of 6-valence Cr ions.
Another object of the present invention provides a kind of preparation method who is used for detecting quickly and easily the test block of content of 6-valence Cr ions.
The invention provides a kind of chromic test block that is used to detect, this test block comprises water-absorbing material, developer diphenylcarbazide, surfactant and the stabilizing agent as carrier.
In the test block of the present invention, surfactant better is to be selected from halogenation hexadecyl trimethylamine, lauryl sodium sulfate, neopelex, polyvinyl alcohol (PVA), cyclodextrin or its combination, and stabilizing agent better is to be selected from polyvinyl alcohol (PVA), soluble starch, phosphate, cyclodextrin or its combination.
Test block of the present invention also comprises acidity regulator and screening agent.Acidity regulator better is to be selected from phthalic anhydride, pyrosulfuric acid, pyrophosphoric acid, toluenesulfonic acid, metatungstic acid or its combination, and screening agent better is to be selected from EDTA, EDTA disodium salt, sodium dihydrogen phosphate, citric acid, tartrate or its combination.
The water-absorbing material that is used as carrier in the test block of the present invention can be selected from chromatographic paper, filter paper or glass fiber material.Test block of the present invention also can comprise the substrate that is used to carry described carrier.
Test block of the present invention is by water-absorbing material being immersed in a kind of solution that contains 0.003-0.03mol/l surfactant and 0.05-0.5wt% stabilizing agent, impregnated in another solution that contains 0.04-0.4mol/l developer diphenylcarbazide again after taking-up is dry and make.
The present invention also provides the preparation method who is used to detect chromic test block, and this method may further comprise the steps: preparation comprises the solution A of surfactant, stabilizing agent and optional screening agent; Preparation comprises the solution B of developer and optional acidity regulator; Water-absorbing material is immersed in the solution A, takes out and drying; The water-absorbing material that will flood solution A again is immersed in the solution B, takes out then and drying.
In solution A, surfactant concentrations is 0.003-0.03mol/l, and the concentration of stabilizing agent is 0.05-0.5wt%, and the concentration of screening agent is 0-0.5mol/l; In solution B, the concentration of developer diphenylcarbazide is 0.04-0.4mol/l, and the concentration of acidity regulator is in the scope of 0-1mol/l.
The preparation method that the present invention is used to detect chromic test block also is included in water-absorbing material through the solution B dipping and after taking out drying, is cut into a certain size, sticks on the substrate, and sealing is preserved.
The advantage of test block of the present invention is: can record chromic content in the very short time (for example 1 minute), measurement result conforms to substantially with National Standard Method, and error is in the semi-quantitative analysis scope.The use of this test block is easy and simple to handle, is particularly suitable for fast-field evaluation, and is safe to carry, convenient, and good stability, and antijamming capability is strong.
Description of drawings
Fig. 1 shows the standard color range that is used to detect chromic test block of one embodiment of the invention.
Embodiment
It is diphenylcarbazide that the present invention detects the developer that comprises in the chromic test block, and this material can form the aubergine complex compound with sexavalent chrome under certain potential of hydrogen condition.When measuring chromic concentration, will and develop the color completely that test block compares according to its shade and standard color range, definite thus chromic concentration through the water sample dipping.
Carrier can be any water-absorbing material, and there is no particular restriction, can for example be chromatographic paper, filter paper, glass fiber material etc.
Test block of the present invention also comprises surfactant and stabilizing agent, and both combination results cooperative effects make that developer is difficult for coming off from carrier, allow chromogenic reaction be able to carry out in solid-liquid interface.
Surfactant better is cationic surfactant, anionic surfactant and non-ionic surfactant.Cationic surfactant is more preferably and is selected from the halogenation hexadecyl trimethylamine, as cetrimonium bronmide (CTMAB), and chlorination hexadecyl trimethylamine (CTMAC) etc.; Anionic surfactant is more preferably and is selected from lauryl sodium sulfate (SDS), neopelex (SDBS); Non-ionic surfactant is selected from polyvinyl alcohol (PVA) and cyclodextrin etc.
Stabilizing agent better is to be selected from polyvinyl alcohol (PVA), soluble starch, phosphate, cyclodextrin or its combination.
Test block of the present invention also can comprise acidity regulator, is used for regulating the potential of hydrogen at interface, but the also interference of exclusive segment ion.Acidity regulator is preferably phthalic anhydride, pyrosulfuric acid, pyrophosphoric acid, toluenesulfonic acid, metatungstic acid or its combination, is more preferably pyrosulfuric acid and toluenesulfonic acid.
Test block of the present invention also can comprise screening agent, is used for sheltering interfering ion.Preferred screening agent is EDTA, EDTA disodium salt, sodium dihydrogen phosphate, citric acid, tartrate or its combination, wherein is more preferably EDTA disodium salt and sodium dihydrogen phosphate.
Test block of the present invention can be strip, sheet or any other suitable form, and the most common form is test paper and test card.
The preparation method of test block of the present invention may further comprise the steps: preparation comprises the solution A of surfactant, stabilizing agent and optional screening agent; Preparation comprises the solution B of developer and optional acidity regulator; Water-absorbing material is immersed in the solution A, takes out and drying; The water-absorbing material that will flood solution A again is immersed in the solution B, takes out then and drying.The thus obtained water-absorbing material that flooded solution A and solution B just can be used to detect chromic content.Yet, be more preferably in the practical application the above-mentioned water-absorbing material that obtains is cut into small pieces, it is sticked on the substrate (for example inertia such as plastic sheet, hard paper hard substrate), make test block.
Test block of the present invention can be used to detect the content of 6-valence Cr ions in the water body, and preferred sensing range is 0-100mg/l.Test block of the present invention is particularly useful for fast-field evaluation, helps water quality is detected, and carries out mass presdiction and disaster prevention, in time controls water pollution, increases water quality.
Below further specify the present invention by specific embodiment, but scope of the present invention is not subjected to these
The restriction of embodiment.
The general preparation method of test block
Surfactant, stabilizing agent and optional screening agent are mixed with water solution A.In the water solution A, surfactant concentrations is 0.003-0.03mol/l normally; The concentration of stabilizing agent is 0.05-0.5wt% normally; The concentration of screening agent in the scope of 0-0.5mol/l, better is 0.05-0.5mol/l usually.Use organic solvent (for example acetone) preparation to contain the solution B of developer and acidity regulator separately.In the solution B, in the scope of 0.04-0.4mol/l, the concentration of acidity regulator in the scope of 0-1mol/l, better is 0.1-1mol/l to the concentration of developer diphenylcarbazide usually usually.
Water-absorbing material be impregnated in the solution A of preparation reach capacity (needing 2 minutes usually), take out dry then.Then the water-absorbing material with drying impregnated in the solution B reach capacity (needing 30 seconds usually) again, takes out the lucifuge drying then.So the water-absorbing material that obtains can be directly used in and detect chromic content.Also it can be cut into small pieces (for example 0.5 * 0.5 centimetre), stick on the plastic sheet (for example 5 * 0.5 centimetres), make test block.After test block can be loaded on and seal in the aluminium plastic bag, cryopreservation.
Embodiment 1
Press the described preparation test block of general preparation method with chromatographic paper (available from Paper Co., Ltd of Xinhua, No. 3 chromatographic papers) as water-absorbing material.Solution A comprises 0.01mol/l lauryl sodium sulfate, 0.2wt% polyvinyl alcohol (PVA), 0.02mol/l EDTA disodium salt and 0.2mol/l sodium dihydrogen phosphate.As solvent obtain solution B, this solution comprises 0.2mol/l diphenylcarbazide, 0.3mol/l phthalic anhydride and 0.1mol/l toluenesulfonic acid with acetone.The chromatographic paper that flooded solution A and solution B is cut into 0.5 * 0.5 centimetre small pieces, stick on 5 * 0.5 centimetres the plastic sheet, obtain test block.
The preparation of standard color range
With reference to National Standard Method preparation Cr (VI) concentration is 0,0.5,2,5,10,30,50 and the standard solution of 100mg/L.Test block is dipped in respectively in the above-mentioned different standard solution, makes reaction zone (being the water-absorbing material region) complete wetting, take out after 1 second kind, dry.Develop the color fully after 30 seconds, color and luster is about 10 minutes stabilization time.According to variable color situation production standard color range.The standard color range is as follows, also can be referring to Fig. 1.
0mg/l 0.5mg/l 2.0mg/l 5.0mg/l 10.0mg/l 30.0mg/l 50.0mg/l 100mg/l
□
■
Annotate: represents colourless substantially, and ■ represents very dark aubergine.
As seen, test block is for the Cr (VI) of 0mol/l Show Color hardly, shows very dark aubergine for the Cr (VI) of 100mol/l, deepens gradually from the aubergine degree of 0.5mol/l to 100mol/l.
Using method
Test block is dipped in the water sample, makes reaction zone (being the water-absorbing material region) complete wetting, take out after 1 second kind, dry.Compare with the standard color range after 1 minute.If the reaction zone color conforms to certain color stage, Cr in the water sample (VI) concentration is the concentration that this color range is indicated.If test block variable color situation is between two color ranges, can estimate that approximate value between two color ranges is as the concentration of water sample Cr (VI) according to gradation of color.
The pH scope of use test part is: [H
+]=4mol/l to pH10.If water sample pH value not in this scope, can be in advance with the H of NaAc or 5%
2SO
4-H
3PO
4Regulated.
Interference test
Get 10mol/l Cr (VI) test solution, add the coexisting ions of different amounts respectively, measure the concentration of Cr (VI) by above-mentioned using method, the test result error range is thought the unlikely test result that influences 5% with interior.The unlikely Cr of influence (VI) concentration determination result's coexisting ion amount is promptly remembered the allowance of making coexisting ion.
Measure the allowance of different ions, their the allowance upper limit is as follows: K
+1000mg/l, Ca
+1000mg/l, Ni
2+1000mg/l, Mg
2+1000mg/l, Zn
2+1000mg/l, Mo (VI) 1000mg/l, Cr
3+500mg/l, Pb
2+200mg/l, Fe
3+100mg/l, Cl
-5000mg/l, SO
4 2-2000mg/l, NO
3 -1000mg/l, PO
4 3-6000mg/l.
Because coexisting ion concentration all is lower than the above-mentioned allowance upper limit in the general water body, so test block of the present invention also has better anti-jamming capability under the situation that does not contain screening agent.But, if will measure the more serious water sample (Fe of pollution
3+＞100mg/l, Pb
2+＞200mg/l, Cr
3+＞500mg/l), then need interfering ion is sheltered in advance or separated.
Stability test
The test block for preparing is deposited with aluminium plastic bag and plastic bottle respectively, a part is preserved in room temperature (15-25 ℃) then, another part is preserved in low temperature (3-5 ℃), take out every other month, mensuration contains the chromium test solution and compares with the standard color range, the result is as follows: plastic bottle is 5 months the stabilization time of room temperature, is 1 year the stabilization time of low temperature; Aluminium plastic bag is 1 year the stabilization time of room temperature, is 1 year half the stabilization time of low temperature.
The fastness test of developer on carrier
The test block that embodiment 1 is made is soaked in the deionized water and takes out after 2 seconds, and the pH value of water is adjusted to [H
+The scope of]=4mol/l to pH10 detects whether there is the developer diphenylcarbazide in the water by introduce the 1mg/l hexavalent chromium in water.Found that not have change color in the water.
In addition, with chromatographic paper (available from Paper Co., Ltd of Xinhua, No. 3 chromatographic papers) preparation test block.Solution A comprises 0.02mol/l EDTA disodium salt and 0.2mol/l sodium dihydrogen phosphate.As solvent obtain solution B, this solution comprises 0.2mol/l diphenylcarbazide, 0.3mol/l phthalic anhydride and 0.1mol/l toluenesulfonic acid with acetone.The chromatographic paper that flooded solution A and solution B is cut into 0.5 * 0.5 centimetre small pieces, stick on 5 * 0.5 centimetres the plastic sheet, obtain test block.Test with above-mentioned identical method, found that to present aubergine in the water, show that the developer diphenylcarbazide comes off from chromatographic paper.
Comparison test
Test paper (model is 1.10012.0001) with National Standard Method, test block of the present invention and German MERCK company is measured many parts of water samples, the results are shown in Table 1, and Cr wherein (VI) concentration unit is mg/l.
Table 1
| Water sample number | National Standard Method | Test block of the present invention | The MERCK test paper |
| 1 | 0.23 | 0.25 | Do not detect |
| 2 | 0.58 | 0.5 | Do not detect |
| 3 | 1.1 | 1.2 | Do not detect |
| 4 | 1.98 | 2 | 0-3 |
| 5 | 2.28 | 2 | 0-3 |
| 6 | 4.22 | 5 | 4.0 |
| 7 | 4.85 | 5 | 5 |
| 8 | 14.97 | 17 | 17 |
| 9 | 26.96 | 28 | 30 |
| 10 | 55.72 | 60 | 65 |
| 11 | 75.9 | 80 | 80 |
By above-mentioned data as seen, the test result of the test result of test block of the present invention and National Standard Method is identical substantially.Compare with the test paper of German MERCK company, the test lower limit of test block of the present invention is lower, and cost is also much lower.
Embodiment 2
Press the described preparation test block of general preparation method with chromatographic paper (available from Paper Co., Ltd of Xinhua, No. 3 chromatographic papers) as water-absorbing material.Solution A comprises 0.03mol/l cetrimonium bronmide, 0.5wt% soluble starch and 0.05mol/l citric acid.As solvent obtain solution B, this solution comprises 0.4mol/l diphenylcarbazide and 0.1mol/l pyrophosphoric acid with acetone.The chromatographic paper that flooded solution A and solution B is cut into 0.5 * 0.5 centimetre small pieces, stick on 5 * 0.5 centimetres the plastic sheet, obtain test block.The gained test block can be used to sxemiquantitative and measures chromic content.
Embodiment 3
Press the described preparation test block of general preparation method with filter paper (available from Paper Co., Ltd of Xinhua, quantitative filter paper) as water-absorbing material.Solution A comprises 0.02mol/l polyvinyl alcohol (PVA), 0.4wt% cyclodextrin and 0.5mol/l tartrate.As solvent obtain solution B, this solution comprises the 0.04mol/l diphenylcarbazide with acetone.The filter paper that flooded solution A and solution B is cut into 0.5 * 0.5 centimetre small pieces, stick on 5 * 0.5 centimetres the plastic sheet, obtain test block.The gained test block can be used to sxemiquantitative and measures chromic content.
Embodiment 4
Press the described preparation test block of general preparation method with chromatographic paper (available from the extraordinary paper plant in Fuyang, No. 3 chromatographic papers) as water-absorbing material.Solution A comprises 0.003mol/l cyclodextrin and 0.05wt% sodium phosphate.As solvent obtain solution B, this solution comprises 0.1mol/l diphenylcarbazide, 0.4mol/l pyrosulfuric acid and 0.6mol/l metatungstic acid with acetone.The chromatographic paper that flooded solution A and solution B is cut into 5 * 0.5 centimetres strip, obtain test block.The gained test block can be used to sxemiquantitative and measures chromic content.
Embodiment 5
Press the described preparation test block of general preparation method with filter paper (available from Paper Co., Ltd of Xinhua, quantitative filter paper) as water-absorbing material.Solution A comprises 0.02mol/l neopelex and 0.3wt% potassium phosphate.As solvent obtain solution B, this solution comprises the 0.3mol/l diphenylcarbazide with acetone.The filter paper that flooded solution A and solution B is cut into 0.5 * 0.5 centimetre small pieces, stick on 5 * 0.5 centimetres the plastic sheet, obtain test block.The gained test block can be used to sxemiquantitative and measures chromic content.
Claims (12)
1. one kind is used to detect chromic test block, and this test block comprises water-absorbing material, developer diphenylcarbazide, surfactant and the stabilizing agent as carrier.
2. test block as claimed in claim 1, it is characterized in that described surfactant is selected from halogenation hexadecyl trimethylamine, lauryl sodium sulfate, neopelex, polyvinyl alcohol (PVA), cyclodextrin or its combination, described stabilizing agent is selected from polyvinyl alcohol (PVA), soluble starch, phosphate, cyclodextrin or its combination.
3. test block as claimed in claim 1 is characterized in that described test block also comprises acidity regulator and screening agent.
4. test block as claimed in claim 3, it is characterized in that described acidity regulator is selected from phthalic anhydride, pyrosulfuric acid, pyrophosphoric acid, toluenesulfonic acid, metatungstic acid or its combination, described screening agent is selected from EDTA, EDTA disodium salt, sodium dihydrogen phosphate, citric acid, tartrate or its combination.
5. test block as claimed in claim 1 is characterized in that described water-absorbing material is selected from chromatographic paper, filter paper or glass fiber material.
6. test block as claimed in claim 1 is characterized in that described test block also can comprise the substrate that is used to carry described carrier.
7. test block as claimed in claim 1, it is characterized in that described test block is by water-absorbing material being immersed in a kind of solution that contains 0.003-0.03mol/l surfactant and 0.05-0.5wt% stabilizing agent, impregnated in another solution that contains 0.04-0.4mol/l developer diphenylcarbazide again after taking-up is dry and make.
8. one kind prepares the method that is used to detect chromic test block as claimed in claim 1, and this method may further comprise the steps:
Preparation comprises the solution A of surfactant and stabilizing agent;
Preparation comprises the solution B of developer;
Water-absorbing material is immersed in the solution A, takes out and drying;
The water-absorbing material that will flood solution A again is immersed in the solution B, takes out then and drying.
9. method as claimed in claim 8 is characterized in that described solution A comprises screening agent.
10. method as claimed in claim 8 is characterized in that described solution B comprises acidity regulator.
11., it is characterized in that in the described solution A that surfactant concentrations is 0.003-0.03mol/l as each described method among the claim 8-10, the concentration of stabilizing agent is 0.05-0.5wt%, the concentration of screening agent is 0-0.5mol/l; In the described solution B, the concentration of developer diphenylcarbazide is 0.04-0.4mol/l, and the concentration of acidity regulator is in the scope of 0-1mol/l.
12., it is characterized in that this method also is included in water-absorbing material through the solution B dipping and after taking out drying as each described method among the claim 8-10, be cut into a certain size, stick on the substrate, sealing is preserved.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02145465 CN1210557C (en) | 2002-11-18 | 2002-11-18 | Test piece for detecting hexavalent chromium and preparing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02145465 CN1210557C (en) | 2002-11-18 | 2002-11-18 | Test piece for detecting hexavalent chromium and preparing method thereof |
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|---|---|
| CN1501066A CN1501066A (en) | 2004-06-02 |
| CN1210557C true CN1210557C (en) | 2005-07-13 |
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| Application Number | Title | Priority Date | Filing Date |
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Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102128829B (en) * | 2010-12-08 | 2013-07-24 | 陕西科技大学 | Method for solid mixed color-developing agent for determining hexavalent chromium |
| CN102121905A (en) * | 2010-12-16 | 2011-07-13 | 上海交通大学 | Test strip for detecting heavy metal-chromium (Cr) in water quality and preparation method thereof |
| CN102411001A (en) * | 2011-08-08 | 2012-04-11 | 山东汇金彩钢有限公司 | Method for rapid detection of hexavalent chromium ions in sewage |
| CN102928354A (en) * | 2012-10-24 | 2013-02-13 | 同济大学 | Preparation method and use method for color development detecting tablets for determining hexavalent chromium in water |
| CN104148009B (en) * | 2014-06-17 | 2017-01-18 | 厦门出入境检验检疫局检验检疫技术中心 | Composite bentonite material capable of quickly identifying hexavalent chromium ions in water with naked eyes as well as preparation method and application of material |
| 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 |
| CN106198518B (en) * | 2016-07-05 | 2019-07-16 | 河南城建学院 | A kind of copper ion quick detection test paper and preparation method thereof |
| CN112525844B (en) * | 2020-11-12 | 2024-06-04 | 德莱福(重庆)医疗器械有限公司 | Stable urea concentration test method in dialyser clearance simulation liquid |
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