HG/T 2840-1997 Water treatment agent aminotri(methylenephosphonic acid) (solid)
Some standard content:
HG/T 2840--1997
This standard is proposed after the revision of GB/T10536-1989. The main differences from the previous version are:
1 "Organic phosphonic acid content" is changed to "active component". 2 The determination method of phosphoric acid content is changed to ammonium phosphomolybdate spectrophotometry 3 The determination method of chloride content is changed to visual comparison method. From the date of entry into force of this standard, GB/T10536-1989 is abolished. 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: Tianjin Chemical Industry Research Institute of the Ministry of Chemical Industry, Wujin Fine Chemical Factory The main drafters of this standard: Huang Jiaxu, Yang Zicheng, Shao Hongqian, Lan Chengjun. This standard was first issued in 1989.
ICS13.060.99;71.100,40
Registration No. 151--1997
Chemical Industry Standard of the People's Republic of China
Water treatment chemicals
Aminotrimethylene phosphonic acid (solid)
Water treatment chemicals - Aminotrimethylene phosphonic acid(solid)Scope
HG/T 2840---1997
This standard specifies the technical requirements, sampling, test methods, marking, packaging, transportation and storage of water treatment chemicals - trimethylolphosphonic acid (solid).
This product is mainly used as a scale inhibitor and corrosion inhibitor in industrial water treatment. Molecular formula: N(CH,PO,H)
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/T 601-1988
Chemical reagents-Preparation of standard solutions for titration analysis (volumetric analysis) G3/T 602---1988
GB/T 603.- 1988
B/T 1250--1989
Chemical reagents-Preparation of standard solutions for determination of impurities (negISO6353-1:1982) Preparation of preparations and products used in test methods for chemical reagents (neqISO6353-1:1982) Expression and determination methods of limit values GB/T 6678-1986
Chemical product sampling total scale
GB/T 6682--1992
Specifications and test methods for water for analytical laboratories 3 Requirements
3.1 Appearance: Self-colored granular solid.
Aminotrimethylphosphonic acid (solid) shall meet the requirements of Table 1. Table 1
Active component.%
Aminotrimethylphosphonic acid content, %
Industrial phosphoric acid (in terms of P ()) content, %
Phosphoric acid (in terms of PO) content, %
Chloride (in terms of PO) content, %
Ministry of Chemical Industry of the People's Republic of China 1997-02-04 Approved 170
Superior product
Qualified product
Implemented on 1997-10-01
Moisture content. %
Water-insoluble matter content, %
pH (1% aqueous solution)
4 Sampling
HG/T 2840
—1997
Continued Table 1
Superior products
4.1 Determine the number of sampling units according to the provisions of Article 6.6 of GB/T6678. Refers to
First-class products
Qualified products
4.2 Use the sampling tube to insert it along the vertical center line of the packaging bag to two-thirds of the bag depth for sampling. Mix the sampled products, reduce them to about 400g by quartering method, and pack them into two clean, dry wide-mouth bottles or polyethylene bottles, and seal them. Label the bottles with: manufacturer name, product name, batch number, sampling date and sampler name. One bottle for inspection For inspection, the other bottle shall be kept for three months for future reference. 4.3 If any indicator of the inspection result does not meet the requirements of this standard, sampling should be carried out again from twice the amount of packaging units for verification. If any indicator of the inspection 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 refer to analytical pure reagents and grade 3 water specified in GB/T6682 unless otherwise specified. The standard solutions, impurity standard solutions, preparations and products used in the test shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603 unless otherwise specified. || tt||Use the rounded value comparison method specified in GB/T1250 to determine whether the test results meet the standards. 5.1 Determination of active components
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(CuS()) about 0.02 mol/L standard titration solution. 5.1.2.2 Sodium hydroxide: 8 g/solution.
5.1.2.3 Ammonia-ammonium chloride buffer solution, pH~10. 5.1.2.4 Neutral red: 1g/L. 60% ethanol solution. 5.1.2.5 Murexide: Grind 1g Murexide with 100g sodium chloride and mix well. 5.1.3 Analysis steps
5.1.3.1 Preparation of test solution
Weigh about 2g of sample (accurate to 0.0002g) and dissolve it in water. Transfer all to a 500mL volumetric flask, dilute to the mark with water, and shake the spoon. This is test solution A.
5.1.3.2 Determination
Pipette 20.00ml test solution A and place it in a 250ml conical flask. Add 20mL of water, 1~~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. The solution temperature must not be lower than 20°C during titration. 5.1.4 Expression of analysis results
The active component X expressed as mass percentage is calculated according to formula (1): 171
Where: C-
HG/T2840--1997
cXV X0. 299
512. 5XcX V
actual concentration of copper sulfate standard titration solution, mol/L; V
volume of copper sulfate standard titration solution consumed in titration, ml; mu
mass of sample, g;
content of aminotrimethylphosphonic acid measured in Article 5.2, %; 0.205+X2
mass of aminotrimethylphosphonic acid expressed in grams equivalent to 1.00mL copper sulfate solution Lc(CuS04)=1.000mol/L);
mass of iminodimethylphosphonic acid expressed in grams equivalent to 1.00mL copper sulfate solution Cc(CuSO4)==1.000mol/L.
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 0.7%. 5.2 Determination of aminotrimethylphosphonic acid content
5.2.1 Method summary
In a medium with a pH of 10, aminotrimethylphosphonic acid forms a stable complex with zinc ions. Add an excess of zinc chloride standard titration solution to the test solution, and titrate with EDTA standard titration solution using chrome black T as an indicator. 5.2.2 Reagents and materials
5.2.2.1 Zinc chloride: c(ZnCl2) about 0.015 mol/L standard titration solution. 5.2.2.2 Disodium ethylenediaminetetraacetic acid: c(EDTA) about 0.015 mol/L standard titration solution. 5.2.2.3 Sodium hydroxide: 8 g/L solution.
5.2.2.4 Ammonia-ammonium chloride buffer solution, pH 10. 5.2.2.5 Neutral red: 1 g/L. 60% ethanol solution. 5.2.2.6 Chrome black T: 1g/L solution.
5.2.3 Analysis steps
Pipette 20.00ml of test solution A into a 500ml conical flask. Add 1 drop of neutral red indicator solution and add sodium hydroxide solution until the solution changes from red to yellow. Add 5mL of ammonia-ammonium chloride buffer solution and then use a pipette to add 20.00mL zinc chloride standard titration solution, heat to 40 (～70℃. Cool to room temperature, add 1～2 drops of chrome black T indicator solution and 10ml water, and titrate with disodium ethylenediaminetetraacetic acid standard titration solution until the solution changes from purple red to blue, which is the end point. 5.2.4 Expression of analysis results
The aminotrimethylphosphonic acid content X expressed as mass percentage is calculated according to formula (2): X (cV-cV)X0.299×100
ma×500
(c2V2-c/V)X747. 5
Where: C2—-actual concentration of zinc chloride standard titration solution, mol /L; V: --- the volume of zinc chloride standard titration solution added, mL; c, -- the actual concentration of disodium ethylenediaminetetraacetic acid standard titration solution, mol/L; V. The volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed in titration, mL; (2)
㎡.- the mass of sample, g;
0.29--- the mass of aminotrimethylphosphonic acid expressed in grams equivalent to 1.00ml. zinc chloride solution [c (ZnCl,) = 1.000mol/L].
5.2.5 Allowable difference
HG/T 2840—1997
Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.5%. 5.3 Determination of phosphorous acid content
5.3.1 Summary of the method
Under the condition of pH 7.0~7.5, iodine oxidizes phosphite to phosphate. Titrate the excess iodine with sodium thiosulfate standard titration solution.
5.3.2 Reagents and materials
5.3.2.1 Ammonium pentaborate (NH,B;O:·4H,O): saturated solution. 5.3.2.2 Sulfuric acid: 1+3 solution.
5.3.2.3 Sodium thiosulfate: c(Na2SO) about 0.1mol/L. standard titration solution. 5.3.2.4 Iodine: c(1/212) about 0.1mol/L solution. Soluble starch: 10g/ L solution.
5.3.3 Analysis steps
Pipette 50.00ml test solution A and place it in a 500mL iodine volumetric flask, add 12mL saturated ammonium pentaborate 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 and titrate with sodium thiosulfate standard titration solution until it turns light yellow, add 1mL~2ml 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. bzxz.net
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 a blank test.
5.3.4 Expression of analysis results
The content of phosphite (PO-) expressed as mass percentage X: Calculate according to formula (3): X c(V.-V)X0. 039 5 ×100
mo×500
39. 5Xc(V.-V)
actual concentration of sodium thiosulfate standard titration solution, mol/L; where;
volume of sodium thiosulfate standard titration solution consumed in blank test, mL, volume of sodium thiosulfate standard titration solution consumed in titration, mL; (3)
mass of sample,;
mass of phosphite equivalent to 1.00mL sodium thiosulfate solution (c(Na,S,(),)=1.000mol/L) expressed in grams 0.0395
5.3.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference between two parallel determination results shall not exceed 0.2%. 5.4 Determination of phosphoric acid content
5.4.1 Summary of method
Under acidic conditions, orthophosphate reacts with ammonium molybdate 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. 5.4.2 Reagents and materials
5.4.2.1 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 with water to 500mL and mix. Store in a brown bottle with a shelf life of 15 days. 5.4.2.2 Ammonium molybdate: 26g/L solution
HG/T 2840—1997
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. 5.4.2.3 Phosphate standard solution: 1mL contains 0.02mgPO4. Prepare according to GB/T602, take 20.00mlL with a pipette, place it in a 100mL volumetric flask, dilute with water to the scale, and shake well. This solution is prepared when used
5.4.3 Instruments and equipment
General laboratory instruments and
5.4.3.1 Spectrophotometer: with an absorption cell with a thickness of 1cm. 5.4.4 Analysis steps
5.4.4.1 Drawing of working curve
In 6 50ml volumetric flasks, add 0 (reagent blank solution), 1.00mL, 2.00mL, 4.00mL, 6.00mL, 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 10 min. 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 each standard reference solution, and draw a working curve with the phosphate content (mg) as the horizontal axis and the corresponding absorbance as the vertical axis. 5.4.4.2 Determination
Use a pipette to transfer 2.0 ml of test solution A into a 50 ml volumetric flask, and add water to about 25 ml. Add 25 ml of water into another 50 ml volumetric flask as a blank test solution. Add 2.0 ml of ammonium molybdate solution and 3.0 ml of ascorbic acid solution, dilute to the mark with water, shake well, and leave for 10 minutes.
Use a spectrophotometer with a 1 cm absorption cell, and measure the absorbance at a wavelength of 710 nm with water as the reference. 5.4.5 Expression of analysis results
The phosphoric acid (PO-) content X expressed as mass percentage is calculated according to formula (4): X = (ml-mo) × 10--)
m × 500
25 (mi-mo)
... (4)
The amount of phosphate found from the working curve based on the measured absorbance of the test solution, rng; Wuhu: m
\The amount of phosphate found from the working curve based on the measured absorbance of the blank test solution, mg; The mass of the sample.
5.4.6 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%. 5.5 Determination of chloride content
5.5.1 Method summary
In nitric acid medium, chloride ions react with silver nitrate to form silver chloride precipitation, making the solution turbid. Visual turbidimetry with standard turbidimetric solution 5.5.2 Reagents and materials
5.5.2.1 Nitric acid: 1+3 solution.
5.5.2.2 Silver nitrate: 17g/L solution.
5.5.2.3 Chloride standard solution: 1mL contains 0.1mgCl. 5.5.3 Analysis steps
Pipette 1.00mL test solution A, place it in a 50mL colorimetric tube, add 1mL nitric acid solution and 1mL silver nitrate solution, dilute with water to 50)ml, shake well, and let it stand for 2min. The turbidity should not be greater than that of the standard turbidimetric solution. Preparation of standard turbidity solution: Use a pipette to take the chloride standard solution (1.00 mL for superior products, 1.60 mL for first-class products, 2.40 mL for qualified products), place it in a 50 mL colorimetric tube, and treat it in the same way as the test solution. 5.6 Determination of water content
5.6.1 Instruments and equipment
5.6.1.1 Weighing bottle: d50mm×30mm. 5.6.2 Analysis steps
Use a weighing bottle that has been dried to constant weight at 105°C±2°C to weigh about 2g of sample (accurate to 0.0002g), and dry it to constant weight at 105°C±2°C.
5.6.3 Expression of analysis results
The moisture content X expressed as mass percentage is calculated according to formula (5): _mj-m2×100.
Where: m---—mass of sample before drying·g; mass of sample after drying, g.
5.6.4 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.5%. 5.7 Determination of water-insoluble content
5.7.1 Instruments and equipment
General laboratory instruments and
5.7.1.1 Crucible filter: filter plate pore size 5μm~～15μm. 5.7.2 Analysis steps
(5)
Weigh about 5g of sample (accurate to 0.0002g), add 100mL of water, and stir thoroughly to dissolve. Filter through a crucible filter that has been dried to constant weight at 110°C±2°C in advance, wash with water 3~4 times, each time with 25mL of water. Dry to constant weight at 110°C±2°C. 5.7.3 Expression of analysis results
Water-insoluble content X expressed as mass percentage. Calculate according to formula (6): X. =m2=m×100.
Where: m2\—mass of molten and insoluble matter, g; m…-mass of crucible, g;
mo mass of sample, g.
5.7.4 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.01%. 5.8 Determination of pH value
5.8.1 Instruments and equipment
5.8.1.1 Acidity meter: accuracy 0.02 pH unit, equipped with saturated calomel reference electrode, glass measuring electrode or composite electrode. 5.8.2 Analysis steps
Weigh 1.00g ± 0.01g sample, add water to dissolve, transfer all to a 100mL volumetric flask, dilute to scale with water, and shake well. (6)
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.
6 Marking, packaging, transportation, storage
6.1 The packaging barrel of the water treatment agent aminotrimethylphosphonic acid (solid) should be painted with a firm mark, including: manufacturer name, product name, grade, trademark, batch number or production date, net weight, factory address and this standard number. 6.2 Each batch of water treatment agent aminotrimethylphosphonic acid (solid) shipped from the factory should be accompanied by a quality certificate, including: manufacturer name, product name, 175
HG/T2840—1997
grade, trademark, batch number or production date, net weight, proof that the product quality complies with this standard and this standard number. 6.3 The water treatment agent aminotrimethylphosphonic acid (solid) is packaged in an iron barrel lined with a polyethylene plastic film bag. Net weight per barrel: 20kg6.4 During transportation, it must be strictly protected from exposure to sunlight and stored in a ventilated and dry warehouse. 6.5 The storage period of water treatment agent aminotrimethylphosphonic acid (solid) is ten months. 176
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