HG/T 2839-1997 Water treatment agent disodium hydroxyethylidene diphosphonate
Some standard content:
HG/r2839
This standard is proposed after the revision of GB/T10537-1989. The main differences from the previous version are: 1. In the determination of active components, only the quinoline phosphomolybdic acid weight method is retained, and the quinoline phosphomolybdic acid volumetric method is cancelled. 2. The determination of phosphate content is changed to ammonium phosphomolybdic acid spectrophotometry. 3. The determination of chloride content is changed to visual turbidimetry. From the date of entry into force of this standard, GB/T10537-1989 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 unit of this standard: Tianjin Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard: Huang Jiaxu, Lan Chengjun, Shao Hongqian. This standard was first issued in 1989.
ICS 13.060.99:71.100.40
Registration No. 150-1997
Chemical Industry Standard of the People's Republic of China
Water treatment chemicals -- DisodiunI-hydroxyethylidene-1, 1-diphosphonate,tetranydrateScope
HG/T 2839..1997
This standard specifies the technical requirements, sampling, test methods and marking, packaging, transportation and storage of the water treatment agent disodium hydroxyethylidene diphosphonate.
This product is mainly used as a scale inhibitor and corrosion inhibitor in industrial water treatment. Molecular formula: C2H0,P,Naz410
Relative molecular mass: 321.99 (according to the 1993 international relative atomic mass) Reference standards
The provisions contained in the following standards constitute the provisions of this standard without being cited 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
GB/T 602 --1988
GB/T 603---1988
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents Preparation of standard solutions for determination of impurities of chemical reagents (neqIS0) 6353-1:1982) Preparation of preparations and products used in test methods for chemical reagents (neaIS) 6353-1*1982) OB/T 1250-1989
GB/T 6678--1986
GB/T 6682.- 1992
GB/T 8946--1988
3 Requirements
3.1 Appearance: self-colored powder.
Methods for expressing and determining limit values General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories Plastic woven bags
2-Hydroxyethyl diphosphonic acid disodium salt shall meet the requirements of Table 1. 3.2
Superior product
Active component (CHa, PNa2·4H20).%
Phosphate (in terms of):) wall content, %
Industrial phosphate (in terms of): content, %
Chemical compound (in terms of): content.%
Water-insoluble matter content.%
Approved by the Ministry of Chemical Industry of the People's Republic of China on February 4, 1997 94.0
First-class product
Qualified product
Implemented on October 1, 1997
4 Sampling
HG/T2839---1997
4.1 Determine the number of sampling units in accordance with the provisions of Article 6.6 of GB/T6678. 4.2 Use sampling The arm is inserted along the vertical center line of the packaging bag to two-thirds of the bag depth to take a sample. Mix the sampled items, use the quartering method to reduce them to about 400, and divide 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 name of the sampler. One bottle is for inspection and the other is kept for three months for future reference. 4.3 Inspection results If any indicator does not meet the requirements of this standard, re-sampling should be carried out from twice the amount of packaging units for verification. If one of the inspection results 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 reagents and water used in the test are analytical pure reagents and grade 3 water specified in GB/T6682. Standard titration solutions, impurity standard solutions, preparations and products, unless otherwise specified, shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603.
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 components
5.1.1 Summary of methods
Disodium hydroxyethylidene diphosphonic acid contains organic phosphonates, phosphates and phosphites. Add sulfuric acid and a decomposition agent and heat to decompose, and they are all converted into orthophosphates. After adding quinomolybdic acid solution, quinoline phosphomolybdate precipitates are generated, which are filtered, washed, dried, weighed, and the total phosphorus content is calculated. The active component is calculated after subtracting the phosphorus content equivalent to phosphate and phosphite. 5.1.2 Reagents and Materials
5.1.2.1 Sulfuric acid: 1+4 solution.
5.1.2.2 Nitric acid.
5.1.2.3 Nitric acid: 1+1 solution.
5.1.2.4 Potassium persulfate.
5.1.2.5 Quinolithium citric acid solution:
Preparation method:
Solution 1: Weigh 70g sodium molybdate and dissolve it in 150mL water; Solution II: Weigh 60g citric acid and dissolve it in a mixture of 85ml nitric acid (5.1.2.2) and 150ml water; Solution: Measure 5ml quinoline and dissolve it in a mixture of 35ml nitric acid (5.1.2.2) and 100mL water. Under constant stirring, first slowly add solution 1 to the center of the solution. Then slowly add solution 1 to solution 1. Mix well and filter after leaving for 24h. Add 280ml acetone to the filtrate, dilute with water to 1000ml, and mix well. Store in colored glass bottles or polyethylene bottles. 5.1.3 Instruments and equipment
· General laboratory instruments and
5.1.3.1 Glass filter: The pore size of the plate is 5#m-~15um5.1.4 Analysis steps
5.1.4.1 Preparation of test solution
Weigh about 2g of sample (accurate to 0.0002g) and dissolve in water. Transfer all to a 500mL volumetric flask, dilute with water to the scale, and shake well. This is test solution A, for determining the content of active ingredients, phosphate, phosphite, and chloride. 5.1.4.2 Determination
Pipette 15.00mL of test solution A and place it in a 400ml tall beaker. Add 10mL sulfuric acid solution, 0.5g potassium persulfate, cover the surface, place on a controllable electric furnace and slowly heat until thick white smoke is almost gone. The solution is viscous. Carefully observe that when fine condensation just appears, remove it and cool it down. The whole process of decomposition is about 30min). Add 100mL water, heat it, wait for the crystals to dissolve, cool it slightly, add 15ml nitric acid solution 5.1.2.3), 50ml quinacridone solution. Cover the surface, boil slightly for 1min, and cool to room temperature. Shake 3~4 times during the cooling process. 16.
HG/T2839--1997
Filter by decantation using a ground filter that has been pre-cooled to 180C ± 5 constant weight. Wash the precipitate in a beaker three times, using 15ml of water each time, transfer all the precipitate to a crucible filter, and continue to wash with water. The total amount of washing water used is about 150mL. Dry at 180°C ± 5 for 45 min, cool in a desiccator, and weigh until constant weight. 5.1.5 Expression of analytical results bzxZ.net
Total phosphorus content X expressed as mass fraction is calculated according to formula (1): X2×0.014×100
m×500
Where…Sample mass·.·
…Mass of quinoline phosphate precipitate.
“Coefficient for converting quinoline phosphomolybdate into phosphorus
Active component (CHOPNa·4HO)X expressed as mass percentage: Calculated according to formula (2): X(X,-X:X0.3261-XX0.3922)×5.1978 Where: X
Total phosphorus content;
X5.2 Measured phosphate Phosphate content (in PO3); 0.326. Phosphate conversion factor to phosphorus; X,: 5.3 Phosphate content (in PO~) measured: .3922 Phosphite conversion factor to phosphorus; .1978 Phosphorus conversion factor to C,HO,P2Na·4H,O. 5.1.6 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference between the two parallel determination results shall not exceed 0.7%. 5.2 Determination of phosphate content
5.2.1 Method Summary
Under acidic conditions, orthophosphate and ammonium molybdate react to form yellow phosphomolybdic acid, which is reduced to phosphomolybdic blue with ascorbic acid. The absorbance is measured at the maximum absorption wavelength (710nm) using a spectrophotometer. 5.2.2 Reagents and Materials
5.2.2.1 Ascorbic acid: 20g/1. Solution. Weigh 10g ascorbic acid and dissolve it in about 50ml of water, add 0.20g disodium ethylenediaminetetraacetic acid and 8mL formic acid, dilute with water to 500ml and mix well. Store in a brown bottle with a shelf life of 15 days. 5.2.2.2 Ammonium molybdate: 26g/1. Solution.
Weigh 13g ammonium molybdate and dissolve it in 200mL of 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. 5.2.2.3 Phosphate standard solution: 1 mL contains 0.02 mg PO4. Prepare according to 13/T602, pipette 20.00 mL, place in a 100 mL volumetric flask, dilute to scale with water, and shake. This solution is prepared now.
5.2.3 Instruments and equipment
· General laboratory instruments and
5.2.3.1 Spectrophotometer: with an absorption cell with a thickness of 1 cm. 5.2.4 Analysis steps
5.2.4.11. Plotting the curve
Add 0 (reagent blank solution), 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of phosphate standard solution to 6 50 mL volumetric flasks respectively. Add water to about 25ml respectively, add 2.0ml ammonium molybdate solution and 3.0ml ascorbic acid solution respectively, dilute to the mark with 165
water, shake and place for 10min. HG/T 2839 - 1997
Use a spectrophotometer. Use a 1cm absorption cell and measure the absorbance at a wavelength of 710nm with water as the reference. Subtract the absorbance of the reagent blank solution from the absorbance of each standard reference solution, and draw a working curve with phosphate content (mg) as the horizontal axis and the corresponding absorbance as the vertical axis. 5.2.4.2 Determination
Use a pipette to transfer 2.0ml of test solution A, place it in a 50ml volumetric flask, and add water to about 25ml. Add 25ml of water to another 50ml volumetric flask as the blank test solution. Add 2.0mL of ammonium molybdate solution and 3.0mL of ascorbic acid solution, dilute to the mark with water, and shake well. Place for i0 min
Use a spectrophotometer with a 1cm absorption cell at a wavelength of 710nm and water as a reference to measure the absorbance. 5.2.5 Expression of analytical results
Phosphate content (in terms of PO-) expressed as mass percentage X: Calculate according to formula (3): Xs = (ml-mo)×10-3
m×500
25(mjmo)
（3）
The amount of phosphate found from the working curve based on the measured absorbance of the test solution, mg; \, -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·g.
5.2.6 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%. 5.3 Determination of phosphite content
5.3.1 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.
5.3.2 Reagents and materials
5.3.2.1 Ammonium pentaborate (NH.BO: 4H,): saturated solution. 5.3.2.2 Sulfuric acid: 1+3 solution.
5.3.2.3 Sodium thiosulfate: c(Na2S,O,) about 0.1mol/L standard titration solution. 5.3.2.4 Iodine: c(1/212) about 0.1mol/1 solution. 5.3.2.5 Soluble starch: 10g/1 solution. 5.3.3 Analysis steps
Pipette 50.00mL test solution A and place it in a 250mL iodine volumetric flask, add 12ml saturated ammonium pentaborate solution, add 25.00ml iodine solution with a pipette, immediately cover the bottle stopper, and place it in a dark place for 10min~15min. Add 15mL sulfuric acid solution and titrate with sodium thiosulfate standard titration solution. When the solution turns light yellow, add 1mL~2mL starch indicator solution and continue to titrate until the blue disappears, which is the end point. Replace the test solution with 50mL water, add the same volume of all reagents, and perform a blank test according to the same steps. 5.3.4 Expression of analytical results
The phosphite (as PO)-) content X expressed as mass percentage is calculated according to formula (4): X, =Vs-V)cX0. 039 5×100
m×500
(Vu-V)cX 39. 5
Wherein: I\.—The volume of sodium thiosulfate standard titration solution consumed in the blank test, mL; V---The volume of sodium thiosulfate standard titration solution consumed in the titration, mL; 166
(4)
HG/T 2839-1997
-Actual concentration of sodium thiosulfate standard titration solution, mol/Lm sample mass, g:
0.0395 The mass of phosphite equivalent to 1.00ml sodium thiosulfate solution Cc (NazS20) = 1.000mol11.3 in grams.
5.3.5 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 0.1%. 5.4 Determination of chloride content
5.4.1 Summary of method
In nitric acid medium, chloride ions react with silver nitrate to form silver chloride precipitation, making the solution turbid. Perform daily turbidimetry with standard turbidimetric solution. 5.4.2 Reagents and materials
5.4.2.1 Nitric acid: 1+3 solution.
5.4.2.2 Silver nitrate: 17g/1 solution.
5.4.2.3 Chloride standard solution: 1ml contains 0.1mgCl. 5.4.3 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 to 50ml with water, shake well, and let stand for 2min. The turbidity should not be greater than the standard turbidity solution. Preparation of standard turbidity solution: Use a pipette to transfer the fluoride standard solution (take 0.40mL for superior products, 0.80mL for first-class products, and 1.20ml 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 water-insoluble content
5.5.1 Reagents and materials
5.5.1.1 Silver nitrate: 17g/1 solution.
5.5.2 Instruments and equipment
General laboratory instruments and
5.5.2.1 Tree filter: filter plate pore size 5um-15μm5.5.3 Analysis steps
Weigh about 10g of sample (accurate to 0.01g), place it in a 200ml beaker, add 100mL of water, and heat to dissolve. Filter through a citrus filter that has been dried to constant weight at 105C~110 (, and wash with hot water until there is no chloride ion (check with silver nitrate solution). Dry at 105C~110C to constant weight.
5.5.4 Expression of analysis results
Water-insoluble matter content X expressed as mass percentage. Calculate according to formula (5): X mmx100-
Where: i—mass of crucible filter and residue after drying, g; m—mass of crucible filter, g;
mass of sample, g.
5.5.5 Allowable difference
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 0.02%. 6 Marking, packaging, transportation and storage
(5)
6.1 The packaging bag of water treatment agent disodium hydroxyethylidene diphosphonate shall be firmly marked, including: Manufacturer's name, product name, grade, trademark, batch number, production date, net weight, factory address and this standard number. 6.2 Each batch of water treatment agent hydroxyethylidene diphosphonic acid disodium shall be accompanied by a quality certificate. The content includes: manufacturer's name, product name, grade, trademark, batch number or production date, net weight, proof that the product quality complies with this standard and this standard number. 167
HG/T28391997
63 Water treatment agent hydroxyethylidene diphosphonic acid disodium adopts double-layer packaging. The inner packaging adopts ethylene plastic film bag with a thickness of not less than 0.05mm, the outer packaging is made of polypropylene plastic woven bags, and its performance and inspection methods shall comply with the relevant provisions of GB/T8946B. The inner bag is tied twice with nylon rope or rope of equivalent quality, and the outer bag is sewn with a sewing machine, with a stitch length of 6mm to 7mm, neat stitches, and uniform stitch lengths. No seamless or skipped stitches. Each bag has a net weight of 25kg, 40kg or 50kg. 6.4 During transportation, it must be strictly prevented from being exposed to rain and sunlight, and stored in a ventilated and dry warehouse. 6.5 The storage period of water treatment agent disodium hydroxyethylidene diphosphonate is one year. 168
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