GB 12593-1990 Working standard reagent (volume) Ethylenediaminetetraacetic acid disodium
Some standard content:
National Standard of the People's Republic of China
Working chemical
Ethylenediaminetetraacetic acid disodium salt This reagent is a white crystalline powder, soluble in water, almost insoluble in ethanol. Molecular formula: CH14N,O;Naz·2H20
Structural formula:
Relative molecular mass: 372.24 (according to the international atomic weight in 1987) 1 Subject content and scope of application
: 2H20
GB 12593-90
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of the working standard reagent (volume) ethylenediaminetetraacetic acid disodium salt. bzxz.net
This standard is applicable to the inspection of the working standard reagent (volume) ethylenediaminetetraacetic acid disodium salt with a content of 99.95% to 100.05%. 2 Reference standards
GB6682
GB9724
GB9728
GB9729
GB9735
GB9739
Chemical reagents
Chemical reagents
Chemical reagents
Preparation of standard solutions for titration analysis (volume analysis)Preparation of standard solutions for determination of impurities
Preparation of preparations and products used in test methods Chemical reagents
Sampling and acceptance rules
Laboratory water specifications
General rules for determination of pH value of chemical reagents
Chemical reagents
General method for determination of sulfate
General method for determination of nitrogen compounds
Chemical reagents
Chemical reagents
General method for determination of heavy metals
Chemical reagents General method for determination of iron
General rules for weighing titration of working standard reagents (volume) GB 10738
Packaging and marking of chemical reagents
HG 3--119
HG 3--. 1168
Chemical reagents
Preparation and determination of clarity standards
Approved by the State Administration of Technical Supervision on December 18, 1990640
Implemented on December 1, 1991
3 Technical requirements
GB 12593-９0
3.1 Disodium ethylenediaminetetraacetate (CioHuN20gNa2·2H20) content, %: 99.95～100.05. 3.2 pH (25C): 4.0~~5.0.
3.3 Complexing force test: qualified.
3.4 Maximum impurity content, %
Clarity test, No.
Fluoride (CI)
Sulfate (SO,)
Aminotriacetic acid (CcH.NOe)
Iron (Fe)
Copper (Cu)
Heavy metals (measured in Pb)
4 Test method
Working basis (capacity)
The standard solution for titration analysis, standard solution for impurity determination and the preparations and products used in this test method shall be prepared in accordance with the provisions of GB601, GB602 and GB603. The water used in the experiment shall meet the specifications of Grade 3 water in GB6682. 4.1 Determination of the content of disodium ethylenediaminetetraacetate (Cloheu Na2·2H20) 4.1.1 Calibration of the concentration of standard solution for zinc chloride titration analysis Weigh 0.5g of the first reference reagent (volume) disodium ethylenediaminetetraacetate after it has been placed in a humidistat with a saturated magnesium nitrate solution (with excess magnesium nitrate crystals) for 7 days, accurate to 0.00001g, place it in a reaction bottle, add 100mL of hot water to dissolve it, cool it, add 10mL of ammonia-ammonium chloride buffer solution A (pH 10), and titrate with the zinc chloride titration analysis standard solution to be calibrated [c(ZnCl2)-0.05mol/kg) according to the provisions of GB10738. Add 3 drops of chrome black T indicator solution (5g/L) when it is close to the endpoint, and continue titrating until the solution changes from blue to reddish purple. The concentration of the standard solution for zinc nitride titration analysis is calculated according to formula (1): c =
m X 0.372 24 X 100..
the concentration of the standard solution for zinc fluoride titration analysis, mol/kg; the mass of the first reference reagent (volume) disodium ethylenediaminetetraacetate, 8; the mass of the standard solution for zinc chloride titration analysis to be calibrated, 8; (1)
the mass of 0.372 24
disodium ethylenediaminetetraacetate expressed in grams equivalent to 1.0000g of the standard solution for zinc chloride titration analysis [c(ZnCl2)=1.0000mol/kg].
4.1.2 Determination of content
Weigh 0.5g of the sample placed in a humidistat in a saturated magnesium nitrate solution (with excess magnesium nitrate crystals) for 7 days, accurate to 0.00001g, and titrate with zinc fluoride titration analysis standard solution [c(ZnCl2)=0.05mol/kg] according to the provisions of Article 4.1.1. The content determination and the calibration of the concentration of the titration analysis standard solution are carried out simultaneously. The content of disodium ethylenediaminetetraacetate (CioHiuN2OgNa22H2O) is calculated according to formula (2): X mol ·× 0. 372 24 × 100
·（2）
GB 12593-90
wherein; X——the percentage content of disodium ethylenediaminetetraacetate, %; ms—the mass of standard solution for zinc chloride titration analysis, mol/kg; c—-the concentration of standard solution for zinc chloride titration analysis, mol/kg: 0.37224-——the mass of disodium ethylenediaminetetraacetate expressed in grams equivalent to 1.0000g standard solution for zinc chloride titration analysis [c(ZnCi2)==1.0000mol/kg];
m ——the mass of the sample, g.
4.2 pH value determination
Weigh 5g of sample, accurate to 0.01g, and dissolve in 100mL of water without carbon dioxide. Determine according to the provisions of GB9724. 4.3 Complexing force test determination
4.3.1 Preparation of sample solution and preparation
4.3.1.1 Sample solution
Weigh 0.372g of sample, dissolve in hot water, cool, transfer to a 100mL volumetric flask, dilute to scale, and shake well. 4.3.1.2 Calcium carbonate solution
Weigh 0.100g of calcium carbonate that has been dried at 200℃ for 2h, place in a 100mL volumetric flask, add 10mL of water and 0.4mL of hydrochloric acid solution (20%), dissolve, neutralize with ammonia solution (10%), dilute to scale, and shake well. 4.3.1.3 Copper sulfate solution
Weigh 0.250g of copper sulfate (CuS0,·5H,0), place it in a 100mL volumetric flask, dissolve it in water, dilute to the mark, and shake well. 4.3.2 Determination method
Measure 5.00mL of sample solution, add 3 drops of ammonia solution (10%) and 2.5mL of ammonium oxalate solution (40g/L), and add 5.00mL of calcium carbonate solution while shaking continuously. The solution should be transparent. If the solution is still turbid after shaking for 1min, add 0.2mL of sample solution. After shaking for 1min, the solution should become transparent.
Measure 5.00mL of sample solution, add 0.5mL of ammonia solution (1%) and 0.5mL of potassium hexacyanoferrate (I) solution (100g/L), and add 4.8mL of copper sulfate solution while shaking continuously. The solution should be light blue-green and no red should be allowed. 4.4 Impurity determination
The sample must be weighed accurately to 0.01g.
4.4.1 Clarity test
Weigh 5g of sample and dissolve it in 100mL of water. Its turbidity shall not be greater than the clarity standard No. 3 specified in HG3-1168. 4.4.2 Chloride
Weigh 0.5g of sample and dissolve it in 10mL of hot water. Add 2mL of nitric acid solution (25%) and shake until the precipitate is completely precipitated. Filter and wash three times with water. Combine the filtrate and washing liquid and dilute to 20mL. Determine according to the provisions of GB9729. The turbidity shall not be greater than the standard. The standard is to take a standard solution for impurity determination containing 0.02mg of nitride (CI), dilute it to 20mL, and treat it in the same way as the sample solution of the same volume.
4.4.3 Sulfate
4.4.3.1 Preparation of sample solution
Weigh 3g of sample, place in platinum blood, slowly heat to carbonize, and burn at 600℃ until white. If necessary, add 5mL of water, evaporate to dryness, and then burn at 600℃, repeat the process until the residue turns completely white. Add 20mL of water, add 6mL of nitric acid solution (25%) dropwise, and evaporate to dryness on a water bath. Dissolve the residue in hot water and dilute to 30mL (filter if necessary). 4.4.3.2 Determination method
Measure 5mL of sample solution and dilute it to 20mL. Determine it according to the provisions of GB9728. The turbidity shall not be greater than the standard. The standard is to take a standard solution for impurity determination containing 0.05mg sulfate (SO.), dilute it to 20mL, and treat it in the same way as the sample solution of the same volume.
4.4.4 Aminotriacetic acid
GB 12593-90
4.4.4.1 Preparation of standard solution for determination of aminotriacetic acid impurities Weigh 1.00g aminotriacetic acid, place it in a 1000mL volumetric flask, add 50mL of water, add sodium hydroxide solution (200g/L) dropwise while shaking until the nitrilotriacetic acid is dissolved, dilute to the scale, and shake well. The concentration of this solution is 1mg/mL. 4.4.4.2 Instrument
Pulse or oscillographic polarograph.
4.4.4.3 Test conditions
Working electrode: dropping mercury electrode;
Reference electrode: silver-silver chloride or saturated calomel electrode; Counter electrode: platinum electrode;
Sensitivity: appropriate selection;
Deoxygenation method: pass fluorine gas for more than 5 minutes;
Scanning potential range: -0.6～-1.1V. 4.4.4.4 Determination method
Weigh 1g of sample, add 30mL of hot water to dissolve, cool, and adjust the pH value of the solution to 10.5~10.7 (controlled by acidometer) with sodium hydroxide solution (100g/L). Add cadmium chloride solution (50g/L) until the solution has a trace of precipitation [the pH value of the solution should be kept at 10.5～10.7 during the addition process. If necessary, adjust with sodium hydroxide solution (100g/L), and dilute to 50mL with sodium hydroxide solution (0.02g/L). When measured with a polarograph, the polarographic wave height shall not be greater than half of the standard wave height. The standard is to take a standard solution for impurity determination containing 0.5 mg aminotriacetic acid (C.HgNOs) and 1 g of sample, add 30 mL of hot water to dissolve, cool, and treat it in the same way as the sample solution of the same volume. 4.4.5 Iron
4.4.5.1 Preparation of sample solution
Weigh 3 g of sample, place it in platinum blood, heat it slowly to carbonize, and burn it at 600°C until it turns white. If necessary, add 5 mL of water, evaporate to dryness, and then burn it at 600°C. Repeat the treatment until the residue turns completely white. Add 10 mL of water to dissolve the residue, add hydrochloric acid solution (20%) dropwise to neutralize, 1 mL in excess, keep warm in a water bath for 10 minutes, and dilute to 30 mL.
4.4.5.2 Determination method
Take 10mL of sample solution, adjust the pH value of the solution to 2 with ammonia solution (10%), and determine according to the provisions of GB9739. The red color shall not be darker than the standard.
The standard is to take a standard solution for impurity determination containing 0.005mg of iron (Fe), add 0.2mL of hydrochloric acid solution (20%), dilute to 10mL, and treat the same volume of sample solution at the same time. 4.4.6 Copper
Take 10mL of the sample solution in 4.4.5.1, add 5mL of ammonium citrate solution (200g/L), adjust the pH value of the solution to 9 with ammonia solution, and dilute to 25mL with an excess of 1mL. Add 1mL of sodium diethyldithiocarbamate solution (1g/L), shake well, add 5mL of isoamyl alcohol for extraction, shake for 1 min, and the yellow color of the organic phase shall not be darker than the standard. The standard is to take a standard solution for impurity determination containing 0.0025mg copper (Cu), dilute it to 10mL, and treat it in the same way as the sample solution of the same volume.
4.4.7 Heavy Metals
Measure 20mL of the sample solution in 4.4.3.1, adjust the pH value of the solution to 4 with ammonia solution (10%), and measure it according to the provisions of GB9735. The dark color shall not be darker than the standard color.
The standard is to take a standard solution for impurity determination containing 0.02mg lead (Pb), add 0.2mL hydrochloric acid solution (20%), dilute it to 20mL, and treat it in the same way as the sample solution of the same volume. 5 Inspection Rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 643
Packaging and marking
According to the provisions of HG 3-119, among which:
Inner packaging form: G-2;
12593--90
Outer packaging form: box made of 600g/m2 boxboard, outer layer of purple electro-optical paper; packaging unit: Class 3.
Additional instructions:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard is drafted by Beijing Chemical Factory. The main drafters of this standard are Zhao Fenglan, Fan Yiming and Qiang Jinglin. 6442mL hydrochloric acid solution (20%), diluted to 20mL, and treated in the same way as the sample solution of the same volume. 5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 643
Packaging and marking
In accordance with the provisions of HG 3-119, among which:
Inner packaging form: G-2;
12593--90
Outer packaging form: box made of boxboard with a specification of 600g/m, and purple electro-optical paper on the outer layer; packaging unit: Class 3.
Additional instructions:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Plant. The main drafters of this standard are Zhao Fenglan, Fan Yiming, and Qiang Jinglin. 6442mL hydrochloric acid solution (20%), diluted to 20mL, and treated in the same way as the sample solution of the same volume. 5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 643
Packaging and marking
In accordance with the provisions of HG 3-119, among which:
Inner packaging form: G-2;
12593--90
Outer packaging form: box made of boxboard with a specification of 600g/m, and purple electro-optical paper on the outer layer; packaging unit: Class 3.
Additional instructions:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Plant. The main drafters of this standard are Zhao Fenglan, Fan Yiming, and Qiang Jinglin. 644
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