Some standard content:
ICS71.060.50
Registration No. 147—1997
Chemical Industry Standard of the People's Republic of China
HG/T2836—1997
Manganese carbonate for soft ferrite use1997-02-04 Issued
Ministry of Chemical Industry of the People's Republic of China
Implemented on 1997-10-01
WHG/T2836—1997
This standard is a revision of the national standard GB/T10503—89
"Manganese carbonate for soft ferrite use", and is adjusted to the chemical industry specimen standard. During the formulation and revision process, the standards of well-known foreign companies were referred to. The main differences from the standards of well-known foreign companies are: 1 The standards of well-known foreign companies have only one level, while this standard is divided into three types and five levels. 2 Control Items This standard has eleven items according to user requirements, seven items according to the standards of famous foreign companies, and five items are the same. Compared with the original national standard: Main differences: 1 The original national standard I-type products are divided into two grades: first-class products and qualified products. This standard divides I-type products into two grades: superior products and first-class products. 2 Indicators: Main content indicators: The index of qualified products of type I is changed from the original 43.5% to 43.046.0%. The calcium content index affects the quality of ferrite products. In order to meet user requirements, the calcium content of type I first-class products is changed from 0.1% to 0.09%, and the calcium content of type I first-class products is changed from 0.35% to 0.30%.
3 Test method: The original national standard aluminum content determination uses chrome blue S as a color developer, and this standard aluminum content determination uses aluminum reagent as a color developer. Standard level: The indicators of type I and type I superior products in this standard are at the international advanced level, and type I is at the international general level. The national standard GB/T10503-89 "Manganese carbonate for soft ferrite use" shall be invalidated from the date of implementation of this standard. 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 Research Institute of the Ministry of Chemical Industry. Drafting units of this standard: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Hunan Chemical Reagent General Factory. The main drafters of this standard: Zhang Jingjuan, Yin Zhaowu, Li Zhijun, Lin Li. This standard is entrusted to the technical unit responsible for standardization of inorganic salt products of the Ministry of Chemical Industry for interpretation. 1
W.bzsoso.coI1Scope
Chemical Industry Standards of the People's Republic of China
Manganese carbonate for soft ferrite use
Manganese carbonate for soft ferrite useHG/T2836-1997
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation and storage of manganese carbonate for soft ferrite use. This standard applies to manganese carbonate made from electrolytic manganese or manganese sulfate, ammonium bicarbonate, etc. This product is mainly used for soft ferrite magnetic materials.
Molecular formula: MnCOs
Relative molecular mass: 114.95 (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. GB191—90 Pictorial symbols for packaging, storage and transportation
GB/T601—88 Chemical reagents
Preparation of standard solutions for titration analysis (volume analysis) GB/T602—88 Preparation of standard solutions for determination of impurities in chemical reagents (negISO6353/1:1982) GB/T603—88 Preparation of preparations and products used in test methods for chemical reagents (neqISO6353/1:1982) GB/T1250—89 Methods for expressing and determining limit values GB/T6003—85||tt| |5 Test sieve
GB/T6678-86 General rules for sampling of chemical products GB/T6682-92
GB/T8946-88
GB/T8947-88
GB/T9723-88
Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) Plastic woven bags
Composite plastic woven bags
General rules for flame atomic absorption spectrometry for chemical reagents GB/T9734-88 General method for determination of aluminum by chemical reagents GB/T 9742—88
3 General method for determination of silicate by chemical reagents
3 Classification
This standard divides soft ferrite manganese carbonate into three types according to the use requirements: Type I and Type I: used for high permeability ferrites, high saturation magnetic induction intensity, low power consumption ferrites, high stability, low loss ferrites.
Type I: used for general ferrites.
4 Requirements
4.1 Appearance: light red to light brown powder. Approved by the Ministry of Chemical Industry of the People's Republic of China on February 4, 1997, and implemented on October 1, 1997
HG/T2836-1997
4.2 Manganese carbonate for soft ferrites shall meet the requirements of Table 1: Table 1 Requirements
Manganese carbonate (in Mn) content
Chloride (in CI) content,
Sulfate (in So.) content,
Silicon dioxide (SiO2) content,
Aluminum (A1) content,
Potassium (K) content,
Sodium (Na) content,
Calcium (Ca) content,
Magnesium (Mg) content,
Lead (Pb) content,
Sieve residue (45μm test) Test and sieve),
5 Sampling
5.1 Each batch of products shall not exceed 10t.
Superior products
First-class products
44.0~46.0
Qualified products
43.0~46.0
5.2 Determine the number of sampling units according to Article 6.6 of GB/T6678-86. When sampling, insert the sampler obliquely from the top of the packaging bag to three-quarters of the depth of the material layer to take samples. Mix the sample thoroughly, reduce it to about 1000g by quartering method, and pack it into two clean and dry ground-mouth bottles. Stick labels on the bottles and indicate: manufacturer name, product name, category, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference. 5. 3 If one of the test results does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-verification. Even if only one of the test results does not meet the requirements of this standard, the entire batch of products will be unqualified. 6 Test method
6.1 Use the rounded value comparison method specified in 5.2 of GB/T1250-89 to determine whether the test results meet the standards. 6.2 The reagents and water used in this standard refer to analytical pure reagents and grade 3 water specified in GB/T6682 unless other requirements are specified. The standard solutions, impurity standard solutions, preparations and products required for the test shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603 unless other requirements are specified. 6.3 Determination of manganese carbonate content
6.3 .1 Method Summary
In phosphoric acid medium, use ammonium nitrate to quantitatively convert divalent manganese in the sample into trivalent manganese at 220-240℃. Use N-phenylanthranilic acid as indicator and titrate with ammonium ferrous sulfate standard titration solution. 6.3.2 Reagents and Materials
6.3.2.1 Phosphoric acid,
6.3.2.2 Sulfuric acid;
6.3.2.3 Sulfuric acid solution: 1+8;
6.3.2.4 Ammonium nitrate;
6.3.2.5 Potassium permanganate solution: 3g/L;
6.3.2.6 N-phenylanthranilic acid indicator solution: 2g/L. Weigh 0.2g of N-phenylanthranilic acid and dissolve it in a small amount of water. Add 0.2g of anhydrous sodium carbonate, heat at low temperature to dissolve, add 100mL of water, and shake well. 6.3.2.7 Sulfur-phosphorus mixed acid: slowly add 150mL of concentrated sulfuric acid and 150mL of phosphoric acid to 100mL of water, shake well, cool to room temperature, and adjust to a slightly reddish color with potassium permanganate solution.
6.3.2.8 Potassium dichromate standard solution: c (1/6K2Cr20) = 0.1mol/L, preparation: weigh about 4.9g of potassium dichromate (accurate to 0.0002g), placed in a 1000mL volumetric flask, add appropriate amount of water to dissolve, dilute to scale, and shake well. The concentration of potassium dichromate standard solution ci is calculated according to formula (1): Ci (1/6 K2Cr20r)
Where: m——the mass of the standard potassium dichromate, g; 49.03—the molar mass of potassium dichromate (1/6K, Cr20z), g/mol. 6.3.2.9 Standard titration solution of ammonium ferrous sulfate: c[Fe(NH)2(SO4)2) is about 0.1mol/L; (1)
Preparation: Weigh about 40g of ammonium ferrous sulfate [Fe(NH)2(SO4)2·6H20), dissolve in 300mL (1+8) sulfuric acid solution, and then add 700mL water. Shake well. The solution is calibrated before use. Calibration: Use a pipette to transfer 25 mL of potassium dichromate standard solution into a 300 mL conical flask, add 10 mL of sulfuric acid mixed acid solution, add water to about 100 mL, and titrate with ammonium ferrous sulfate standard titration solution until the orange-yellow color disappears. Then add 2 drops of N-phenylated o-phenylaminobenzoic acid indicator solution and continue titrating until the purple-red color changes to bright green as the end point. The concentration c of ammonium ferrous sulfate standard titration solution is calculated according to formula (2): V.·
Wherein: V1—the volume of potassium dichromate standard solution transferred, mL; C1——the actual concentration of potassium dichromate standard solution, mol/L; V
—the volume of ammonium ferrous sulfate standard titration solution consumed in titration, mL. 6.3.3 Analysis steps
(2)
Weigh about 0.5g of sample (accurate to 0.0002g), place in a 300mL conical flask, moisten with a small amount of water, add 25mL of phosphoric acid, shake well, heat and boil until the liquid surface is calm and white smoke is slightly emitted (the temperature at this time is 220-240℃), remove from the heat source, immediately add 2g of ammonium nitrate, shake well to drive away the yellow smoke, add 100mL of water after cooling slightly, shake well to dissolve the salts, and cool to room temperature. Titrate with ammonium ferrous sulfate standard titration solution until light red, add two drops of N-phenylanthranilic acid indicator solution, and continue titrating until the solution changes from red to bright yellow, which is the end point. bzxz.net
6.3.4 Expression of analysis results
The content of manganese carbonate (in terms of Mn) Xi expressed as mass percentage is calculated according to formula (3):3
WHG/T2836—1997
X1 =0. 054 94 ·0·×100
5.494·cV
Wherein: c——actual concentration of standard ammonium ferrous sulfate titration solution, mol/L; V——volume of standard ammonium ferrous sulfate titration solution consumed in titration, mL; m——mass of sample, gs
0.05494——mass of manganese in grams equivalent to 1.00mL standard ammonium ferrous sulfate titration solution c(Fe（NH)(SO,)·6Hz0）=1.000mol/L.
6.3.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.3%. 6.4 Determination of chloride content
6.4.1 Method summary
In nitric acid medium, chloride ions and silver ions generate insoluble silver chloride. When the chloride ion content is low, silver chloride is suspended for a certain period of time, making the solution turbid, which can be used for visual turbidimetric determination of chloride. 6.4.2 Reagents and solutions
6.4.2.1 30% hydrogen peroxide;
6.4.2.2 Nitric acid solution: 1+2;
6.4.2.3 Silver nitrate solution: 17g/L;
6.4.2.4 Chloride standard solution: 1mL solution contains 0.1mgCl. 6.4.3 Analysis steps
Weigh about 1.0g of the sample (accurate to 0.01g), place it in a 25mL colorimetric tube, add a small amount of water to moisten it, add nitric acid solution to completely dissolve the sample, add 1 drop of hydrogen peroxide to fade the dark color, add 1mL of silver nitrate solution, dilute to the scale with water, and shake well. Let it stand for 2 minutes, and the turbidity should not be deeper than the standard turbidity solution. Preparation of standard turbidity solution: Use a pipette to transfer 1mL (Type I and Type I), 2mL (Type I first-class product), 3mL (Type I qualified product) of chloride standard solution, add water to about 10mL, add 1mL of nitric acid, and start from "add 1mL of silver nitrate solution" and treat it in the same way as the test solution.
6.5 Determination of sulfate content
6.5.1 Summary of the method
In an acidic medium, sulfate ions and barium ions generate insoluble barium sulfate. When the sulfate ion content is low, the sulfate lock is suspended for a certain period of time, making the solution turbid, which can be used for the visual turbidimetric determination of sulfate. 6.5.2 Reagents and solutions
6.5.2.1 Hydrochloric acid solution: 1+1;
6.5.2.2 30% hydrogen peroxide;
6.5.2.3 Ethanol solution: 1+2;
6.5.2.4 Sulfate ethanol solution: Weigh 0.148g of anhydrous sodium sulfate dried to constant weight at 105~110℃, dissolve it in ethanol solution, and dilute it to 1000mL with ethanol solution.
6.5.2.5 Barium chloride solution: 250g/L;
6.5.2.6 Sulfate standard solution: 1mL solution contains 0.1mgSO;6.5.3 Analysis steps
Preparation of test solution:
HG/T2836—1997
Weigh about 1.0g of sample (accurate to 0.01g), place in a 100mL beaker, add 10mL of water, drop hydrochloric acid solution to completely dissolve the sample, add 1 drop of hydrogen peroxide to fade the color, heat and boil for 2min, cool to room temperature, transfer to a 100mL volumetric flask, dilute to scale, and shake well. Use a pipette to transfer the test solution (20mL for Type I; 5mL for Type I and Type I first-class products; 3mL for Type I qualified products) and place in a 50mL beaker, add water to 25mL, and add 0.5mL of hydrochloric acid solution. Preparation of standard turbidity solution:
Use a pipette to transfer the sulfate standard solution: 1 mL of type I; 1.5 mL of type I and type I into a 50 mL beaker, add water to 25 mL, and add 0.5 mL of hydrochloric acid solution.
Add 0.25 mL of sulfate ethanol solution and 1 mL of barium chloride solution to two 25 mL colorimetric tubes, respectively, and place them for 1 minute (seed solution). Pour the test solution and standard turbidity solution in the beaker into the colorimetric tubes, shake well, and place them for 10 minutes. The turbidity of the test solution shall not be deeper than that of the standard turbidity solution. 6.6 Determination of silicon dioxide content
Method 1: Spectrophotometry (arbitration method)
6.6.1 Summary of the method
Same as Article 3 of GB/T9742-88.
6.6.2 Reagents and Materials
6.6.2.1 Anhydrous Sodium Carbonate
6.6.2.2 Hydrochloric Acid Solution: 1+1, 1+3 and 1+10;
6.6.2.3 Perchloric Acid Solution: 3+2;
6.6.2.4 Sulfuric Acid Solution: 1+3;
6.6.2.5 Silver Nitrate Solution: 17g/L;
6.6.2.6 Oxalic Acid Solution: 100g/L;
6.6.2.7 Sodium Molybdate Solution: 140g/L; Place 35g of sodium molybdate dihydrate (Na2MoO,·2H20) in a polyethylene beaker, dissolve it in 200mL of water at about 50℃, cool it to room temperature, transfer it to a 250mL volumetric flask, and dilute it to the mark. Store it in a polyethylene beaker and filter it before use if necessary.
6.6.2.8 Ascorbic acid solution: 10g/L, freshly prepared; 6.6.2.9 Methyl red indicator solution: 1g/L ethanol solution; 6.6.2.10 Silicon standard solution: 1mL solution contains 0.01mgSiO2. Use a pipette to transfer 10mL of silicon standard solution prepared according to GB/T602 into a 100mL volumetric flask, dilute to the mark, and shake well. 6.6.3 Instruments and equipment
6.6.3.1 Spectrophotometer: with a 2cm absorption cell; 6.6.3.2 Platinum crucible: 20mL.
6.6.4 Analysis steps
6.6.4.1 Drawing of working curve
Add 0.00, 1.00, 2.00, 4.00, 6.00 and 8.00mL silicon standard solution, the corresponding silicon dioxide content is 0, 10, 20, 40, 60 and 80μg, add water to each solution to 25mL, add 4mL 1 + 3 hydrochloric acid solution, 10mL sodium molybdate solution, shake for 10min, add 5mL oxalic acid solution, mix well, let stand for 5min, add 30mL sulfuric acid solution, 5mL ascorbic acid solution, dilute to scale with water, shake well. After 10min, within 40min, use a 2cm absorption cell on a spectrophotometer at a wavelength of 650nm, adjust the zero point with water to measure the absorbance. Draw a working curve with the silicon dioxide content as the horizontal axis and the corresponding absorbance minus the absorbance of the reagent blank as the vertical axis. 6.6.4.2 Determination
Weigh about 5 g of sample (accurate to 0.01 g), place in a 300 mL beaker, moisten with water, add 50 mL of 1+1 hydrochloric acid solution to dissolve the sample, add 30 mL of perchloric acid, cover with a watch glass, slowly heat to allow the perchloric acid vapor to reflux along the wall of the beaker, maintain for 15 min, cool, add 50 mL of warm water, filter with slow quantitative filter paper, wash the precipitate with warm 1+10 hydrochloric acid solution, scrub the wall of the beaker with a glass rod with an eraser for 5 minutes, and then wash with hot water until there is no chloride ion (check with silver nitrate solution). Transfer the precipitate and filter paper into platinum, ash at low temperature, cool, add 1g sodium carbonate, heat to melt, add 20mL warm water to dissolve after cooling, transfer to a 250mL volumetric flask, use methyl red indicator as an indicator, neutralize with 1+3 hydrochloric acid solution, dilute to scale with water, and shake well. Transfer 5-25mL of solution to a 100mL volumetric flask, start from "add 4mL 1+3 hydrochloric acid solution..." and do the same operation as when drawing the working curve. When measuring the sample, use the same reagent and dosage, the same procedure, but do not add the sample to perform a blank test. 6.6.5 Expression of analysis results
The silicon dioxide (SiO2) content X expressed as mass percentage is calculated according to formula (4): (mimo)
m×10×250
0.025(m1-mo)
-The mass of silicon dioxide obtained from the working curve based on the measured absorbance of the test solution, μg; Where: m1-
The mass of silicon dioxide obtained from the working curve based on the measured absorbance of the blank test solution, g; V-The volume of the test solution transferred, mL;
-The mass of the sample, g.
6.6.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.002%. Method 2: Gravimetric method
6.6.1 Method Summary
(4)
Dissolve the sample in hydrochloric acid, evaporate to dryness on a water bath, filter, add hydrofluoric acid to convert silicon dioxide into silicon tetrafluoride and volatilize, measure the loss to determine the content of silicon dioxide.
6.6.2 Reagents and Materials
6.6.2.1 Hydrofluoric acid;
6.6.2.2 30% hydrogen peroxide;
6.6.2.3 Hydrochloric acid solution: 1+1, 1+3 and 1+24;6.6.2.4 Sulfuric acid solution: 1+1;
6.6.3 Instruments and Equipment
Platinum crucible: 20mL.
6.6.4 Analysis steps
Weigh 30.0g of sample (accurate to 0.1g), place in a 300mL beaker, moisten with a small amount of water, slowly add 60mL of 1+1 hydrochloric acid solution to dissolve, add 5-10 drops of hydrogen peroxide to fade the dark color, evaporate to dryness on a water bath, and cool. Dissolve the residue with 50mL of 1+3 hydrochloric acid solution, add water to 200mL, filter with slow quantitative filter paper, wash the precipitate and beaker with warm 1+24 hydrochloric acid solution, and then wash the precipitate with warm water until the filtrate is neutral, transfer the filter paper and the precipitate to platinum glass, dry and ashed, place in a 1000℃ high-temperature electric furnace to constant weight, add 34 drops of sulfuric acid solution to moisten, add 5mL of hydrofluoric acid, place on a hot plate to heat until the white smoke is gone, and place in a 1000℃ high-temperature electric furnace to constant weight.
6.6.5 Expression of analysis results
Silicon dioxide (SiO2) content X expressed as mass percentage: calculated according to formula (5): Xs=m1=m2×100
(5)
WHG/T2836—1997
Wherein: m1——mass of platinum crucible and residue, g; m2——mass of platinum crucible and residue after hydrofluoric acid treatment, g; m——mass of sample, g.
6.6.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.003%. 6.7 Determination of aluminum content
6.7.1 Summary of method
Same as Article 3 of GB/T9734—88.
6.7.2 Reagents and materials
6.7.2.1 Hydrochloric acid solution: 1+1;
6.7.2.2 30% hydrogen peroxide;
6.7.2.3 Acetic acid solution: 1+2;
6.7.2.4 Ascorbic acid solution: 100g/L, freshly prepared;6.7.2.5 Red ammonium tricarboxylate solution: 0.5g/L; Acetic acid-ammonium acetate buffer solution (pH 4-5);6.7.2.6
6.7.2.7 Aluminum standard solution: 1mL solution contains 0.01mgAl; Pipette 10mL of aluminum standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute to the scale with water, and shake well. 6.7.3 Analysis steps
Weigh 1.00g of the sample (accurate to 0.01g), place it in a 50mL beaker, moisten it with a small amount of water, add hydrochloric acid solution until the sample dissolves, add 1 drop of hydrogen peroxide to fade the dark color, evaporate to dryness on a water bath, and cool. Dissolve it with water, transfer the solution to a 100mL volumetric flask, dilute to the scale, shake well, this is test solution A. Keep this solution for the determination of magnesium. Transfer test solution A (2.00mL for Type I and Type I superior products, 1.00mL for Type I first-class products and Type I first-class products, and 0.4mL for Type I qualified products) to a 25mL colorimetric tube, add water to 10mL, and start from adding "1mL acetic acid solution..." According to Article 6 of GB/T9734-88, the red color should not be deeper than the standard colorimetric solution. The standard colorimetric solution is to transfer 0.2 mL of aluminum standard solution into a 25 mL colorimetric tube, add water to 10 mL, and start from "add 1 mL of acetic acid solution..." and treat it in the same way as the test solution. 6.8 Determination of potassium content
6.8.1 Summary of method
Same as Article 3 of GB/T9723-88.
6.8.2 Reagents and solutions
6.8.2.1 30% hydrogen peroxide;
6.8.2.2 Hydrochloric acid solution: 1+1;
6.8.2.3 Potassium standard solution: 1 mL of solution contains 0.1 mg K. 6.8.3 Instruments and equipment
6.8.3.1 Atomic absorption spectrophotometer;
6.8.3.2 Light source: potassium hollow cathode lamp;
6.8.3.3 Wavelength: 766.5nm,
6.8.3.4 Flame: acetylene-air.
6.8.4 Analysis steps
6.8.4.1 Preparation of test solution
Weigh about 25g of sample (accurate to 0.1g). Place in a 200mL beaker, moisten with water, add hydrochloric acid solution to completely dissolve the sample, add a few drops of hydrogen peroxide to fade the color, transfer to a 250mL volumetric flask, dilute to scale, and shake well. This is test solution B, used for the determination of potassium, sodium, calcium, and lead content. 7
6.8.4.2 Determination
HG/T2836—1997
Use a pipette to take 10mL of test solution B (6.8.4.1), a total of four portions. Place each portion in a 100mL volumetric flask. The following operations are carried out according to 6.2.2 of GB/T9723-88, starting from “. (1) portion without adding standard solution”. 6.8.5 Expression of analytical results
The potassium (K) content X expressed as a mass percentage is calculated according to formula (6): X, = X100×10-6
m×250
Wherein: c—the potassium concentration obtained from the working standard curve, uμg/mL; V-
the volume of sample solution B (6.8.4.1) transferred, mL; -the mass of the sample weighed in 6.8.4.1, g. 6.8.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.002%, and the absolute difference of Type I qualified products shall be 0.004%.
6.9 Determination of sodium content
6.9.1 Method summary
Same as Article 3 of GB/T9723-88.
6.9.2 Reagents and solutions
Sodium standard solution: 1mL solution contains 0.1mgNa. 6.9.3 Instruments and equipment
6.9.3.1 Atomic absorption spectrophotometer;
6.9.3.2 Light source: sodium hollow cathode lamp;
6.9.3.3 Wavelength: 588.9nm;
6.9.3.4 Flame: acetylene-air.
6.9.4 Analysis steps
Use a pipette to transfer 5mL of test solution B (6.8.4.1), a total of four portions. Place each in a 100mL volumetric flask, and the following operations are carried out according to Article 6.2.2 of GBT9723-88 starting from ". (1) portion without adding standard solution, ...". 6.9.5 Expression of analysis results
Sodium (Na) content X expressed as mass percentage: calculated according to formula (7): cX100×10-6
m×250
Wherein: c-
——the sodium concentration found from the working curve, μg/mL; V——the volume of test solution B (6.8.4.1) pipetted, mL; m——the mass of the sample weighed in 6.8.4.1, g. 8
W.6.9.6 Allowable difference
HG/T2836—1997
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.004%, and the absolute difference of type I qualified products shall be 0.006%.
6.10 Determination of calcium content
6.10.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.10.2 Reagents and solutions
Calcium standard solution: 1 mL of solution contains 0.1 mg Ca. 6.10.3 Instruments and equipment
6.10.3.1 Atomic absorption spectrophotometer; 6.10.3.2 Light source: calcium hollow cathode lamp; 6.10.3.3 Wavelength: 422.7 nm;
6.10.3.4 Flame: acetylene-air.
6.10.4 Analysis steps
Use a pipette to transfer 5 mL (0.5 mL for type I) of test solution B (6.8.4.1), a total of four portions. Place them in 100mL volumetric flasks respectively. The following operations are carried out according to 6.2.2 of GB/T9723-88. (1) Do not add standard solution, ·.".
6.10.5 Expression of analysis results
Calcium (Ca) content X expressed as mass percentage. Calculate according to formula (8): Xe=e×100×10-6
m×250
Where: c-
-Calcium content obtained from the working curve Concentration, μg/mL; - Volume of test solution B (6.8.4.1), mL; V
-The mass of the sample weighed in 6.8.4.1, g. 6.10.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.006%, 0.02% for Type I first-class products, 0.07% for Type I first-class products, and 0.2% for Type I qualified products. 6.11 Determination of magnesium content||tt| |6.11.1 Method Summary
Same as Article 3 of GB/T9723-88.
6.11.2 Reagents and Solutions
Magnesium Standard Solution: 1mL solution contains 0.1mgMg. 6.11.3 Instruments and Equipment
6.11.3.1 Atomic Absorption Spectrophotometer; 6.11.3.2 Light Source: Magnesium Hollow Cathode Lamp; 6.11.3.3 Wavelength: 285.2nm;
6.11.3.4 Flame: Acetylene-air.
6.11.4 Analysis steps
W.bzsoso.coDHG/T2836—1997
Use a pipette to transfer 10mL of test solution A (6.7.3), (0.5mL for Type I qualified products), a total of four portions. Place each in a 100mL volumetric flask, and follow the following operations according to Section 6.2.2 of GB/T9723-88, starting from .… (1) without adding standard solution, ..·.”
6.11.5 Expression of analysis results
The magnesium (Mg) content X expressed as mass percentage is calculated according to formula (9): X, =X100×10-6
Wherein: c—the magnesium concentration found from the working curve, μg/mL; V——the volume of the test solution A (6.7.3) transferred, mL; m
-the mass of the sample weighed in 6.7.3, g. 6.11.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.004%, 0.01% for the first-class product of type I, 0.02% for the first-class product of type II, and 0.1% for the qualified product of type I. 6.12 Determination of lead content
6.12.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.12.2 Reagents and solutions
Lead standard solution: 1 mL of solution contains 0.1 mg of Pb. 6.12.3 Instruments and equipment
6.12.3.1 Atomic absorption spectrophotometer; 6.12.3.2 Light source: lead hollow cathode lamp; 6.12.3.3 Wavelength: 217.0 nm;
6.12.3.4 Flame: acetylene-air.
6.12.4 Analysis steps
Use a pipette to transfer 20 mL of test solution B (6.8.4.1), a total of four portions. Place each in a 100 mL volumetric flask, and follow the following operations according to GB/T9723-88, Section 6.2.2, starting from "… (1) portion without adding standard solution." 6.12.5 Expression of analysis results
The lead (Pb) content X expressed as a mass percentage is calculated according to formula (10): Xg = ×100X10-6
m×250
Wherein: c—the lead concentration found from the working curve, ug/mL; V—the volume of the test solution B (6.8.4.1) transferred, mL; m
-the mass of the sample weighed in 6.8.4.1, g. (10)
W.5 Expression of analysis results
Calcium (Ca) content X expressed as mass percentage. Calculated according to formula (8): Xe=e×100×10-6
m×250
Wherein: c-
-Calcium concentration found from the working curve, μg/mL;-Volume of test solution B (6.8.4.1) transferred, mL; V
-The mass of the sample weighed in 6.8.4.1, g. 6.10.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.006%, 0.02% for Type I first-class products, 0.07% for Type I first-class products, and 0.2% for Type I qualified products. 6.11 Determination of magnesium content
6.11.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.11.2 Reagents and solutions
Magnesium standard solution: 1 mL of solution contains 0.1 mg Mg. 6.11.3 Instruments and equipment
6.11.3.1 Atomic absorption spectrophotometer; 6.11.3.2 Light source: magnesium hollow cathode lamp; 6.11.3.3 Wavelength: 285.2 nm;
6.11.3.4 Flame: acetylene-air.
6.11.4 Analysis steps
W.bzsoso.coDHG/T2836—1997
Use a pipette to transfer 10mL of test solution A (6.7.3), (0.5mL for Type I qualified products), a total of four portions. Place each in a 100mL volumetric flask, and the following operations are carried out according to Article 6.2.2 of GB/T9723-88 starting from .… (1) portion without adding standard solution, ..·.”.
6.11.5 Expression of analysis results
The magnesium (Mg) content X expressed as mass percentage is calculated according to formula (9): X, =X100×10-6
Wherein: c—the concentration of magnesium found from the working curve, μg/mL; V——the volume of test solution A (6.7.3) transferred, mL; m
-the mass of the sample weighed in 6.7.3, g. 6.11.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.004%, 0.01% for Type I first-class products, 0.02% for Type II first-class products, and 0.1% for Type I qualified products. 6.12 Determination of lead content
6.12.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.12.2 Reagents and solutions
Lead standard solution: 1mL of solution The liquid contains 0.1 mg Pb. 6.12.3 Instruments and equipment
6.12.3.1 Atomic absorption spectrophotometer; 6.12.3.2 Light source: lead hollow cathode lamp; 6.12.3.3 Wavelength: 217.0 nm;
6.12.3.4 Flame: acetylene-air.
6.12.4 Analysis steps
Use a pipette to transfer 20 mL of test solution B (6.8.4.1), a total of four portions. Place each in a 100 mL volumetric flask, and the following operations are carried out according to GB/T9723-88 Section 6.2.2 starting from "… (1) portion without adding standard solution." 6.12.5 Expression of analysis results
The lead (Pb) content X expressed as mass percentage is calculated according to formula (10): Xg =×100X10-6
m×250
Wherein: c—the lead concentration found from the working curve, ug/mL; V—the volume of test solution B (6.8.4.1) transferred, mL; m
-the mass of the sample weighed in 6.8.4.1, g. (10)
W.5 Expression of analysis results
Calcium (Ca) content X expressed as mass percentage. Calculated according to formula (8): Xe=e×100×10-6
m×250
Wherein: c-
-Calcium concentration found from the working curve, μg/mL;-Volume of test solution B (6.8.4.1) transferred, mL; V
-The mass of the sample weighed in 6.8.4.1, g. 6.10.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.006%, 0.02% for Type I first-class products, 0.07% for Type I first-class products, and 0.2% for Type I qualified products. 6.11 Determination of magnesium content
6.11.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.11.2 Reagents and solutions
Magnesium standard solution: 1 mL of solution contains 0.1 mg Mg. 6.11.3 Instruments and equipment
6.11.3.1 Atomic absorption spectrophotometer; 6.11.3.2 Light source: magnesium hollow cathode lamp; 6.11.3.3 Wavelength: 285.2 nm;
6.11.3.4 Flame: acetylene-air.
6.11.4 Analysis steps
W.bzsoso.coDHG/T2836—1997
Use a pipette to transfer 10mL of test solution A (6.7.3), (0.5mL for Type I qualified products), a total of four portions. Place each in a 100mL volumetric flask, and the following operations are carried out according to Article 6.2.2 of GB/T9723-88 starting from .… (1) portion without adding standard solution, ..·.”.
6.11.5 Expression of analysis results
The magnesium (Mg) content X expressed as mass percentage is calculated according to formula (9): X, =X100×10-6
Wherein: c—the concentration of magnesium found from the working curve, μg/mL; V——the volume of test solution A (6.7.3) transferred, mL; m
-the mass of the sample weighed in 6.7.3, g. 6.11.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.004%, 0.01% for Type I first-class products, 0.02% for Type II first-class products, and 0.1% for Type I qualified products. 6.12 Determination of lead content
6.12.1 Summary of the method
Same as Article 3 of GB/T9723-88.
6.12.2 Reagents and solutions
Lead standard solution: 1mL of solution The liquid contains 0.1 mg Pb. 6.12.3 Instruments and equipment
6.12.3.1 Atomic absorption spectrophotometer; 6.12.3.2 Light source: lead hollow cathode lamp; 6.12.3.3 Wavelength: 217.0 nm;
6.12.3.4 Flame: acetylene-air.
6.12.4 Analysis steps
Use a pipette to transfer 20 mL of test solution B (6.8.4.1), a total of four portions. Place each in a 100 mL volumetric flask, and the following operations are carried out according to GB/T9723-88 Section 6.2.2 starting from "… (1) portion without adding standard solution." 6.12.5 Expression of analysis results
The lead (Pb) content X expressed as mass percentage is calculated according to formula (10): Xg =×100X10-6
m×250
Wherein: c—the lead concentration found from the working curve, ug/mL; V—the volume of test solution B (6.8.4.1) transferred, mL; m
-the mass of the sample weighed in 6.8.4.1, g. (10)
W.
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