HG/T 2841-1997 Water treatment agent aminotri(methylenephosphonic acid)
Some standard content:
HG/T 2841--1997
This standard is proposed after the revision of ZB/TG71003-1989. Compared with the previous version, the main contents of the revision are: the active component index is changed from the control range to the control lower limit. 2 According to the actual production situation in recent years, the content indexes of phosphorous acid, phosphoric acid and chloride have been adjusted, and the level has been improved. 3 The calcium chelation value index has been added.
3 The determination of chloride content has been changed to the self-visual turbidimetric method. From the date of entry into force of this standard, it replaces ZB/TG71003-1989. This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Industry Research Institute of the Ministry of Chemical Industry. Drafting units of this standard: Wujin Fine Chemical Plant, Luohe Oriental Chemical Plant, Changzhou Jianghai Chemical Plant, Tianjin Chemical Industry Research Institute Affiliated Chemical Plant The main drafters of this standard: Yang Zicheng, Tian Guoqin, Wu Guoqing, Zhang Heru, Zhu Chuanjun, this standard was first issued in 1989.
ICS 13. 060. 99;71.100. 40
Registration No.
152.---1997
Chemical Industry Standard of the People's Republic of China
Water treatment chemicals
Aminotrimethylene phospkonic acid
Water treatment chemicals -- Aminotrimethylene phospkonic acid1
HG/T 2841 1997
Replaces ZB/TG 71003--1989
This standard specifies the technical requirements, sampling, test methods, marking, packaging, transportation and storage of the water treatment agent aminotrimethylene phospkonic acid.
The product is mainly used as a scale inhibitor and corrosion inhibitor in industrial water treatment. Molecular formula: N(CH,PO,H2)3
Relative molecular mass: 299.0 (according to the 1993 international relative atomic mass) 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB 191-1990
Packaging and transport pictorial marking
Chemical reagents-Preparation of standard solutions for titration analysis (volume analysis) GB/T 601..-.1988
GB/T 602--1988
GB/T 603--1988
Preparation of standard solutions for determination of impurities (ne4ISO)) 6353-1:1982) Chemical reagents
Preparation of preparations and products used in chemical reagent test methods (neaISO6353-1:1982) GB/T1250--1989
Expression and determination methods of limit values GB/T 6678-1986
General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories GB/T 6682--1992
3 Requirements
Appearance: Colorless or slightly yellow transparent liquid. Water treatment agent
Aminotrimethylenephosphonic acid shall meet the requirements of Table 1. Table 1
Active components, %
Industrial phosphoric acid (in terms of P) content, %
Phosphoric acid (in terms of P) content, %
Chloride (in terms of CI) content, %
Ministry of Chemical Industry of the People's Republic of China1997-02-04Approved 178
Superior product
First-class product
Qualified product
Implemented on 1997-10-01
PH value ()% aqueous solution)
Density (2 (（）.g/cm
Calcium integration value.mg/g
4Sampling
HG/T 2841-—1997
Continued Table 1
Superior product
1. 5 ~2. 5
1. 5～2. 5
Qualified products
1. 5 ~2. 5
4.1 Determine the number of sampling units according to Article 6.6 of GB/T6678. 4.2 Stir thoroughly before sampling. Use a glass tube or polyethylene plastic tube to insert into the barrel at two-thirds of the depth to take samples. The total amount should be no less than 1000ml. Mix thoroughly, divide into two clean, dry bottles with ground stoppers, and seal. Attach labels to the bottles, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is for inspection, and the other bottle is kept for three months for future reference. 4.3 If any indicator of the inspection result does not meet the requirements of this When the standard requires, samples should be taken from twice the amount of packaging units for verification. If any indicator in the verification result does not meet the requirements of this standard, the entire batch of products cannot be accepted. 5 Test method
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682. The standard solutions, impurity standard solutions, preparations and products used in the test, unless otherwise specified, are prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603. ||tt| |The rounded value comparison method specified in GB/T1250 is used to determine whether the test results meet the requirements. 5.1 Determination of active component content
5.1.1 Method summary
In a medium with a pH of 10, organic phosphonic acid forms a stable complex with copper ions, and murexide is used as an indicator and titrated with copper sulfate standard titration solution.
5.1.2 Reagents and materials
5.1.2.1 Copper sulfate: c(CuSO,) about 0.02 mol/L standard titration solution. 5.1 .2.2 Sodium hydroxide: 8g/L solution.
5.1.2.3 Hydrogen-ammonium chloride buffer solution·pH→10. 5.1.2.4 Neutral red: 1g/L 60% ethanol solution. 5.1.2.5 Ammonium violaceum: 1g ammonium violaceum is ground with 100g sodium chloride and mixed. 5.1.3 Analysis stepsWww.bzxZ.net
5.1.3.1 Preparation of test solution
Weigh about 4g of sample (accurate to 0.0002g), transfer all to a 500mL volumetric flask, dilute with water to the scale, and shake well. This is test solution A.
5.1.3.2 Determination
Pipette 20.00ml. test solution A, place it in a 250mL conical flask, add 20mL water, 1 to 2 drops of neutral red indicator solution, and add sodium hydroxide solution until the solution changes from red to yellow. Add 5mL ammonia-ammonium chloride buffer solution and 0.1g murexide indicator, and titrate with copper sulfate standard titration solution until the solution turns yellow-green, which is the end point. 5.1.4 Expression of analytical results
The active component content X expressed in mass percentage is calculated according to formula (1): 179
HG/T 2841-1997
X, c×0.299
ma×500
Where: .—actual concentration of copper sulfate standard titration solution.mol/.V-volume of copper sulfate standard titration solution consumed in titration, ml.; ma·mass of sample + g;
ma 1.00mL copper sulfate standard solution L (CuS0) - 1.000mol/L equivalent to the mass of aminomethylphosphonic acid expressed in grams.
5.1.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference between the two parallel determination results shall not exceed 0.2%. 5.2 Determination of phosphorous acid content
5.2.1 Method summary
Under the condition of pH 7.0~7.5, iodine oxidizes phosphite to phosphate. Titrate the excess iodine with sodium thiosulfate standard titration solution.
5.2.2 Reagents and materials
5.2.2.1 Ammonium pentaborate (NHBO, 4H0): saturated solution. 5.2.2.2 Sulfuric acid: 1+3 solution.
5.2.2.3 Sodium thiosulfate: r(Naz.03) about 0.1mol/L standard titration solution. 5.2.2.4 Iodine: c(1/212) about 0.1mol/L solution. 5.2.2.5 Soluble starch: 10g/L solution. 5.2.3 Analysis steps
Pipette 50.00ml test solution A and place it in a 500ml iodine volumetric flask, add 12mL saturated ammonium pentoxide solution, add 25.00ml iodine solution with a pipette, cover the bottle stopper, and place it in a dark place for 10min. Add 10mL sulfuric acid solution, titrate with sodium thiosulfate standard titration solution until it turns light yellow, add 1ml2mlL starch indicator solution, and continue titrating until the blue color disappears, which is the end point. The solution temperature must not be lower than 20 during operation
In another 500ml iodine volumetric flask, add 50ml water. At the same time as the determination, follow the same steps and add all reagents of the same volume to perform the Minnan test.
5.2.4 Expression of analytical results
The phosphorous acid (as PO-) content X expressed as mass percentage is calculated according to formula (2): X = c(VV)X0. 039.5 × 100
39. 5 Xe(Vu-V)
Wherein: actual concentration of sodium thiosulfate standard titration solution, molLV,·volume of sodium thiosulfate standard titration solution consumed in blank test, mL; V-volume of sodium thiosulfate standard titration solution consumed in titration, mL; (2)
mmass of sample, g;
0.0395--.1.00mL sodium thiosulfate standard solution Cc (Na2S.O.)-1.000mol/L equivalent to the mass of phosphite expressed in grams.
5.2.5
The arithmetic mean of the parallel determination results shall be taken as the determination result. The absolute difference between the two parallel determination results shall not exceed 0.2%. 5.3 Determination of phosphoric acid content
5.3.1 Summary of method
HG/T 2841-.- 1997
Under acidic conditions, orthophosphate and ammonium molybdate react to form yellow phosphomolybdic heteropoly acid, which is reduced to phosphomolybdic blue with ascorbic acid. The absorbance is measured at the maximum absorption wavelength (710nm) using a spectrophotometer. 5.3.2 Reagents and materials
5.3.2.1 Ascorbic acid: 20g/l. solution. Weigh 10g ascorbic acid and dissolve it in about 50mL water, add 0.20g disodium ethylenediaminetetraacetic acid and 8mL formic acid, dilute to 500ml with water, and mix well. Store in a brown bottle, shelf life 15d. 5.3.2.2 Ammonium molybdate: 26g/L solution.
Weigh 13g ammonium molybdate and dissolve it in 200mL water, add 0.5g potassium antimony tartrate and 120mL concentrated sulfuric acid. After cooling, dilute with water to 500ml and mix well. Store in a brown bottle. 5.3.2.3 Phosphate standard solution: 1ml. contains 0.02mgPO. After preparing according to GB/T602, use a pipette to transfer 20.00mL, place it in a 100mL volumetric flask, dilute with water to the scale, and shake it. This solution should be prepared when used.
5.3.3 Instruments and equipment
General laboratory instruments and
5.3.3.1 Spectrophotometer: with an absorption cell with a thickness of 1cm. 5.3.4 Analysis steps
5.3.4.1 Drawing of working curve
In 5 50mL volumetric flasks, add 0 (reagent blank solution), 1.00mL, 2.00mL, 4.00mL, 6.00ml, and 8.00ml of phosphate standard solution respectively. Add water to about 25mL respectively, add 2.0mL of ammonium molybdate solution and 3.0mL of ascorbic acid solution respectively, dilute to the scale with water, shake well, and let stand for 10min. Use a spectrophotometer with a 1cm absorption cell at a wavelength of 710nm and water as a reference to measure the absorbance. Subtract the absorbance of the reagent blank solution from the absorbance of the standard reference solution, and draw the working curve with the phosphate content (mg) as the horizontal axis and the corresponding absorbance as the vertical axis. 5.3.4.2 Determination
Use a pipette to take 1.0 ml of test solution A and place it in a 50 mL volumetric flask. Add water to about 25 ml. Add 25 ml to another 50 mL volumetric flask, and use water as a blank test solution. Add 2.0 mL of ammonium molybdate solution and 3.0 mL of ascorbic acid solution respectively, dilute to the mark with water, shake and leave for 10 min.
Use a spectrophotometer with a 1 cm absorption cell at a wavelength of 710 nm and water as a reference to determine the absorbance. 5.3.5 Expression of analytical results
The phosphoric acid (P()) content X expressed as a mass percentage. Calculate according to formula (3): X; = (ml-mo) × 10-s
50(ml-mo)
Where: \1--the amount of phosphate found from the working curve based on the measured absorbance of the test solution, mg; m--the amount of phosphate found from the working curve based on the measured absorbance of the blank test solution, mg; m--the mass of the sample, g.
5.3.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference between the two parallel determination results shall not exceed 0.05%. 5.4 Determination of chloride content
(3)
5.4.1 Summary of the method
In the nitric acid medium, chloride ions react with silver nitrate to form silver chloride precipitation, making the solution turbid. Visual turbidimetry is performed with the standard turbidimetric solution. 181
5.4.2 Reagents and materials
5.4.2.1 Nitric acid: 1+3 solution.
5.4.2.2 Silver nitrate: 17g/1. solution
HG/T 2841—1997
5.4.2.3 Chloride standard solution: 1ml. Contains 0.1mgCl. 5.4.3 Analysis steps
Pipette 1.00mL test solution A, place in a 50mL colorimetric tube, add 1mL nitric acid solution and 1mL silver nitrate solution, dilute to 50mL with water, shake well, and let stand for 2min. The turbidity should not be greater than that of the standard turbidity solution. Preparation of standard turbidity solution: Use a pipette to transfer the chloride standard solution (0.80ml for superior products, 1.60ml for standard products, and 2.80mL for qualified products), place it in a 50ml colorimetric tube, and treat it in the same way as the test solution. 5.5 Determination of pH value
5.5.1 Instruments and equipment
5.5.1.1 Acidometer: Accuracy 0.02pH unit, equipped with saturated calomel reference electrode, glass measuring electrode or composite electrode. 5.5.2 Analysis steps
Weigh 1.00g ± 0.01g of sample, transfer all to a 100mL volumetric flask, dilute to the scale with water, and shake well. Pour the test solution into a beaker, place it on an electromagnetic stirrer, immerse the electrode in the solution, and start stirring. Read the pH value on the positioned acidometer.
5.6 Density determination
5.6.1 Instruments and equipment
5.6.1.1 Densitometer: graduation value is 0.0012/cm3. : 5.6.1.2 Constant temperature water bath: temperature is controlled at 20C±0.1C. 5.6.1.3 Glass measuring cylinder: 500ml.c
5.6.7.4 Thermometer: 0~50C, graduation value is 0.1℃. 5.6.2 Analysis steps
Pour the sample into a clean and dry measuring cylinder without bubbles, and place the measuring cylinder in a constant temperature water bath at 20C. After the temperature stabilizes, slowly put the clean and dry densitometer into the sample, and its lower end should be more than 2cm away from the bottom of the cylinder and cannot touch the cylinder wall. The upper end of the densitometer exposed outside the liquid surface should not be exposed to more than 2-3 graduations of liquid. After the density meter is stable in the sample, read the scale at the lower edge of the meniscus of the density meter (except for the density meter with a scale for reading the upper edge of the meniscus), which is the density of the 20C sample. 5.7 Determination of calcium chelation value
5.7.1 Summary of method
Calcium chelation value (mg/) refers to the number of milligrams of calcium carbonate chelated per gram of sample. Add sodium carbonate to the test solution. Add sodium hydroxide solution to maintain the pH value of the solution at 11. Titrate with calcium standard solution until persistent turbidity appears. 5.7.2 Reagents and materials
5.7.2.1 Sodium carbonate: 20g/1 solution.
5.7.2.2 Sodium hydroxide: 40g/1 solution. 5.7.2.3 Potassium hydroxide: 200g/1 solution. Disodium ethylenediaminetetraacetic acid: c (EDTA) about 0.05mol/L standard titration solution. 5.7.2.4
5. 7. 2. 5
5. 7. 2. 6
Calcium-carboxylic acid indicator: Grind and mix 1.0 mg calcium-carboxylic acid with 100 g sodium fluoride. Calcium standard titration solution: 1 mL contains about 10.0 mg Ca. Preparation: Weigh 27.72 g anhydrous calcium fluoride, dissolve it in water, and dilute to 1000 ml. a.
Standardization: Transfer 5.00 mL of calcium standard solution and place it in a 250 mL conical flask. Add 30 ml of water, 5 ml of potassium hydroxide solution, and about 0.1 mg of calcium-carboxylic acid indicator. Titrate with disodium ethylenediaminetetraacetic acid standard titration solution. The end point is when the solution changes from purple-red to bright blue. c. Calculation:
The concentration of Ca expressed in mg/ml. is calculated according to formula (4): 182
HG/T 2841--1997
VcX0. 040X103
Wherein: V.---the volume of the standard titration solution of disodium ethylenediaminetetraacetic acid consumed in the titration, ml; the actual concentration of the standard titration solution of disodium ethylenediaminetetraacetic acid, mol/1.; 4
0.040....The mass of calcium expressed in grams equivalent to 1.00ml disodium ethylenediaminetetraacetic acid solution Cc (EDTA) = 1.000mol/1.].
5.7.3 Instruments and equipment
General laboratory instruments and
5.7.3.1 Acidity meter: equipped with saturated calomel reference electrode and glass measuring electrode or composite electrode5.7.3.2 Electromagnetic stirrer: equipped with a stirrer. 5.7.4 Analysis steps
Weigh about 2g of sample (accurate to 0.01g), put it in a 250mL beaker, add 100mL of water, put the beaker on the electromagnetic stirrer, put in the stirrer, and start stirring. After the sample is mixed evenly, add 10mL of sodium carbonate solution. Insert the electrode into the solution and add sodium hydroxide solution until the pH is 11. Lift the electrode, add water to 150mL, and then insert the electrode. Titrate with calcium standard titration solution, adding sodium hydroxide solution while titrating, and maintain the pH of the solution at 11. The end point is when the solution becomes obviously and persistently turbid.
5.7.5 Expression of analysis results
Calcium chelation value X expressed in nig/g is calculated according to formula (5): X, 2.50XcV
Actual concentration of calcium standard titration solution, mg/mL; where · --
VThe volume of calcium standard titration solution consumed in titration, mL; m--mass of sample in g;
2.50--Coefficient of calcium conversion into calcium carbonate. 5.7.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference between the two parallel determination results shall not exceed 5 mg/g. 6 Marking, packaging, transportation, purchase and storage
6.1 The packaging barrels of water treatment agent aminotrimethylphosphonic acid should be painted with firm markings, including: manufacturer name, product name, grade, trademark, batch number or production date, net weight, factory address and "mark 3 upward" as specified in GB191. 6.2 Each batch of aminotrimethylphosphonic acid, a water treatment agent, shall be accompanied by a quality certificate. The contents shall include: manufacturer name, product name, grade, trademark, batch number or production date, net weight, proof that the product quality complies with this standard and the number of this standard. 6.3 The aminotrimethylphosphonic acid, a water treatment agent, shall be packaged in polyethylene plastic barrels with a net weight of 25kg per barrel; or in iron-plastic barrels with a net weight of 200kg per barrel.
6.4 During transportation, it shall be strictly prevented from exposure to sunlight and stored in a ventilated and dry warehouse. 6.5 The storage period of aminotrimethylphosphonic acid, a water treatment agent, is ten months. 183
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