Some standard content:
National Standard of the People's Republic of China
Working reference reagent capacity)
Zinc oxide
Working chemical
Zinc oxide
GB 1260--90||tt| |Replace GB1260-77
This reagent is white or light yellow crystalline powder, insoluble in water, soluble in acid, nitrogen water and alkali metal hydroxide, and absorbs carbon dioxide and moisture in the air.
Divided formula: Zno
Relative molecular mass: 81.389 (according to 1987 international atomic weight) Subject content and scope of application
This standard specifies the working reference reagent (capacity) zinc oxide Technical requirements, test methods, inspection rules, packaging and marking. This standard is applicable to the inspection of zinc oxide with a content of 99.95% to 100.05% of the working reference reagent (capacity). 2 Reference standards
GB601
GB602
GB603
GB619
GB 6682
GB9723
GB 9728||tt ||GB9729
Preparation of chemical reagents for standard solutions for titration analysis (volume analysis)
Chemical reagents
Chemical reagents
Chemical reagents
For impurity determination Preparation of standard solutions
Preparation, sampling and acceptance rules for preparations and products used in test methods
Laboratory water specifications
Chemical reagents
Chemical reagents
General rules for flame atomic absorption spectrometry
General methods for determination of sulfate
General methods for determination of chemical reagents chloride
General rules for weighing and titration of working reference reagents (volume) GB10738
HG 3--119
HG 3--1168
3 Technical requirements
Packaging and marking of chemical reagents
Preparation and determination methods of chemical reagent clarity standards 3.1|| tt||Zinc oxide (Zn0) content, %: 99.95-~100.05. 3.2 Maximum impurity content, %:
Name
Clarity test, No.
Loss on ignition|| tt||Free base
Working benchmark (capacity) approved by the State Bureau of Technical Supervision on 1990-12-18
2
0.2
Qualified
1991- 12-01 Implementation
533
Rat compounds (CI)
Sulfur compounds (as SO.)
Nitrate (NO)
Magnesium ( Mg) | | tt | )
Test method
GB1260
Continued table
90
Working benchmark (capacity)
0.001
0.005| |tt||0.003
0.002
0.005
0.0005
0.003
0. 001 6
Titrimetric analysis used in this test method The standard solutions, standard solutions for impurity determination, and preparations and products used in the test methods are prepared in accordance with the provisions of GB601, GB602, and GB603. The experimental water should comply with the third-level water specifications in GB6682. 4.1 Determination of zinc oxide (ZnO) content
Weigh 0.1g of the sample after measuring the weight loss on ignition, accurate to 0.00001g, place it in a reaction bottle, moisten it with a small amount of water, and add hydrochloric acid solution (20% ) until the sample is dissolved, add 75mL of water, adjust the pH value of the solution to 8 with ammonia solution (10%), add 10mL of ammonia-ammonium chloride buffer solution A (pH10) and 3 drops of chrome black T indicator solution (5g/L), According to the regulations of GB10738, titrate with disodium ethylenediaminetetraacetate standard solution (c(EDTA) = 0.05mol/kg) until the solution changes from purple to pure blue. Do a blank test at the same time. The disodium ethylenediaminetetraacetate standard solution [c(EDTA)-0.05mol/kg] is prepared by gravimetric method using the first reference reagent (capacity) disodium ethylenediaminetetraacetate (see Appendix A (Supplement)). The relative error of concentration shall not be greater than 5×10-4%. The zinc oxide (ZnO) content is calculated according to formula (1): × = (m = m)c× 0. 081 389 × 100m3
where: |tt||C
0.081 389
m3
·Percent content of zinc oxide, %;
Quality of disodium ethylenediaminetetraacetate standard solution, 8; Mass of blank test disodium ethylenediaminetetraacetate standard solution, g; concentration of disodium ethylenediaminetetraacetate standard solution, mol/kg; (1) Www.bzxZ.net
and 1.0000g disodium ethylenediaminetetraacetate The sodium standard solution (c(EDTA) = 1.0000mo1/kg) is equivalent to the mass of zinc oxide expressed in grams;
The mass of the sample, g.
Note: () In formula (1), ml, mz, and ms should be corrected for buoyancy in accordance with the provisions of Appendix B (Supplement) in GB10738 before being substituted into the formula. ②The density of zinc oxide is 5.61g/cm2.
4.2 Determination of impurities
The sample must be weighed accurately to 0.01g.
4.2.1 Clarity test
Weigh 6g sample and dissolve it in 94mL water and 6mL sulfuric acid. Its turbidity shall not be greater than the clarity standard No. 2 specified in HG3-1168.
4.2.2 Weight loss on ignition
Weigh 1.5g sample, accurate to 0.0001g, place it in a platinum crucible with constant weight at 800℃, gradually increase the temperature, and burn at 800℃ to Constant weight. The sample after constant weight was retained for content determination. The weight loss on ignition is calculated according to formula (2):
534
In the formula: g;
m2·The mass of the sample after burning to constant weight, g. 4.2.3 Free base
GB 1260--90
X=
+1
my
n2
X 100|| tt||(2)
Weigh 2g sample, add 20mL water, boil, filter and cool. Add 2 drops of phenol indicator solution (10g/L) to the filtrate, and the solution must not turn pink.
4.2.4 Fluoride
Weigh 1g of sample, add 5mL of water, dropwise add nitric acid solution (25%) until the sample is dissolved, dilute to 20mL, and measure according to the regulations of GB9729. The turbidity required shall not be greater than the standard. The
standard is to take the standard solution for impurity determination containing 0.01mg chloride (CI), dilute it to 20mL, and treat it in the same way as the sample solution of the same volume at the same time.
4.2.5 Sulfur compounds
Weigh 1g of sample, add 15mL of water, 0.2mL of anhydrous sodium carbonate solution (50g/L) and 1mL of 30% hydrogen peroxide, and boil slowly until bubbles escape. All. Add hydrochloric acid solution (20%) dropwise to dissolve, steam on a water bath until almost dry, add 20mL of water, and measure according to the regulations of GB9728. The displayed turbidity shall not be greater than the standard. The
standard is to take the standard solution for impurity determination containing 0.05mg sulfate (SO.), dilute it to 20mL, and process it with the same volume of sample solution at the same time.
4.2.6 Nitrate
Weigh 0.5g sample, add 10mL water, 1mL sodium chloride solution (100g/L) and 1mL sodium indigo disulfonate solution Cc (ClcHgN2Na2OgS2) - 0.001 mol/L], add 10mL sulfuric acid within 10~15s while shaking, leave it for 10min, add 10mL water, and shake the spoon. The blue color must not be lighter than the standard. The standard is to take a standard solution for impurity determination containing 0.015mg nitrate (NO3) and treat it in the same way as the sample. 4.2.7 Magnesium | | tt | |tt|| Flame: acetylene-air.
4.2.7.2 Measurement method
Weigh 5g of the sample, moisten it with a small amount of water, add hydrochloric acid solution (20%) dropwise until the sample is dissolved, and dilute to 100mL. Take 20mL, four parts in total, and measure according to the provisions of GB97236.2.2.
4.2.8 Calcium
is measured according to the provisions of GB9723, where:
4.2.8.1 Instrument conditions
Light source: calcium hollow cathode lamp;
Wavelength: 422.7nm; ||tt ||Flame: Acetylene-Air.
4.2.8.2 Determination method
Weigh 10g of the sample, moisten it with a small amount of water, add hydrochloric acid solution (20%) dropwise until the sample is dissolved, and dilute to 100mL. Take 20mL, four parts in total, and measure according to the provisions of Article 6.2.2 of GB9723. 4.2.9 Iron
535
GB 1260-90
Weigh 1g sample, add 10mL water, add hydrochloric acid solution (20%) dropwise until the sample is dissolved, and dilute to 20mL . Add 2mL of sulfosalicylic acid solution (100g/L) and shake well. Add 6mL of ammonia water and shake well. The yellow color must not be darker than the standard. The standard is to take a standard solution for impurity determination containing 0.005 mg of iron (Fe), dilute it to 20 mL, and treat it in the same way as the sample solution of the same volume at the same time.
4.2.10 Lead
Measured according to the provisions of GB9723, among which:
4.2.10.1 Instrument conditions
Light source: lead hollow cathode lamp;
Wavelength :283.3nm;
Flame: acetylene-air.
4.2.10.2 Determination method
Weigh 25g of the sample, moisten it with a small amount of water, add hydrochloric acid solution (20%) dropwise until the sample is dissolved, and dilute to 150mL. Take 30mL, four parts in total, and measure according to the provisions of Article 6.2.2 of GB9723. 4.2.11 Reduced potassium permanganate substance
Weigh 5g sample, add 125mL sulfuric acid solution (1+5) to dissolve, add 0.1mL potassium permanganate titration analysis standard solution C (→KMnO,)= 0. 1 mol/L), shake well, and heat to boiling. The red color must not disappear completely. 5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 6 Packaging and marking
According to the provisions of HG 3-119, including:
Inner packaging form: G-2;
Outer packaging form: in boxes with a specification of 600 persons/m2 Box made of cardboard, with purple electro-optical paper on the outer layer; packaging unit: Category 3.
536
GB1260
Appendix A
90
Preparation of reference solution
(supplement)
base solution The balances and magnetic codes used in the preparation are all three-level balances and two-level codes. The weighing method uses the substitution method. The water used should be placed in a constant temperature room in advance, and its temperature should be the same as that of the constant temperature room. A1 Drying of the first reference reagent (volume)
Dry the first reference reagent (volume) under specified conditions to constant weight. A2 Sample Weighing
Calculate the amount of the first reference reagent (capacity) required based on the concentration and mass of the reference solution to be prepared. Weigh the sample after constant weight in Article A1 according to the above calculation, and the mass of the sample is buoyantly corrected according to the formula in Appendix B of GB10738.
Dissolution of A3 sample
Place the sample weighed in Article A2 into a beaker, add a small amount of water to dissolve it, and place it in a constant temperature room for 1 to 2 hours. Preparation of A4 reference solution
Weigh a dry volumetric flask. After weighing, transfer the solution obtained in Article A3 to the volumetric flask. Add water until it is slightly less than the mass of the solution to be prepared. Weigh and drop Add a small amount of water, continue to weigh, repeat several times until the required mass is measured, and mix well. The mass of the solution is buoyantly corrected according to the formula in Appendix B of GB10738.
Calculation of A5 reference solution concentration
The reference solution concentration is calculated according to the following formula:
mi
×1000
c
m2· M
concentration of the reference solution, mol/kg;
where:——
m
m2
the first reference reagent after buoyancy correction ( The mass of the reference solution after buoyancy correction, g; M
The relative molecular mass of the first base reagent (capacity), g/mol. Additional notes:
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 Factory. This standard is drafted by Beijing Chemical Plant. The main drafters of this standard are Wang Sunjie, Chen Hua and Liu Dongni. This standard was first published in 1977.
537
Heat to boiling. The red color must not disappear completely. 5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 6 Packaging and marking
According to the provisions of HG 3-119, including:
Inner packaging form: G-2;
Outer packaging form: in boxes with a specification of 600 persons/m2 Box made of cardboard, with purple electro-optical paper on the outer layer; packaging unit: Category 3.
536
GB1260
Appendix A
90
Preparation of reference solution
(supplement)
base solution The balances and magnetic codes used in the preparation are all three-level balances and two-level codes, and the weighing method uses the substitution method. The water used should be placed in a constant temperature room in advance, and its temperature is the same as that of the constant temperature room. A1 Drying of the first reference reagent (volume)
Dry the first reference reagent (volume) under specified conditions to constant weight. A2 Sample Weighing
Calculate the amount of the first reference reagent (capacity) required based on the concentration and mass of the reference solution to be prepared. Weigh the sample after constant weight in Article A1 according to the above calculation, and the mass of the sample is buoyantly corrected according to the formula in Appendix B of GB10738.
Dissolution of A3 sample
Place the sample weighed in Article A2 into a beaker, add a small amount of water to dissolve it, and place it in a constant temperature room for 1 to 2 hours. Preparation of A4 reference solution
Weigh a dry volumetric flask. After weighing, transfer the solution obtained in Article A3 to the volumetric flask. Add water until it is slightly less than the mass of the solution to be prepared. Weigh and drop Add a small amount of water, continue to weigh, repeat several times until the required mass is measured, and mix well. The mass of the solution is buoyantly corrected according to the formula in Appendix B of GB10738.
Calculation of A5 reference solution concentration
The reference solution concentration is calculated according to the following formula:
mi
×1000
c
m2· M
concentration of the reference solution, mol/kg;
where:——
m
m2
the first reference reagent after buoyancy correction ( The mass of the reference solution after buoyancy correction, g; M
The relative molecular mass of the first base reagent (capacity), g/mol. Additional notes:
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 Factory. This standard is drafted by Beijing Chemical Plant. The main drafters of this standard are Wang Sunjie, Chen Hua and Liu Dongni. This standard was first published in 1977.
537
Heat to boiling. The red color must not disappear completely. 5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 6 Packaging and marking
According to the provisions of HG 3-119, including:
Inner packaging form: G-2;
Outer packaging form: in boxes with a specification of 600 persons/m2 Box made of cardboard, with purple electro-optical paper on the outer layer; packaging unit: Category 3.
536
GB1260
Appendix A
90
Preparation of reference solution
(supplement)
base solution The balances and magnetic codes used in the preparation are all three-level balances and two-level codes, and the weighing method uses the substitution method. The water used should be placed in a constant temperature room in advance, and its temperature is the same as that of the constant temperature room. A1 Drying of the first reference reagent (volume)
Dry the first reference reagent (volume) under specified conditions to constant weight. A2 Sample Weighing
Calculate the amount of the first reference reagent (capacity) required based on the concentration and mass of the reference solution to be prepared. Weigh the sample after constant weight in Article A1 according to the above calculation, and the mass of the sample is buoyantly corrected according to the formula in Appendix B of GB10738.
Dissolution of A3 sample
Place the sample weighed in Article A2 into a beaker, add a small amount of water to dissolve it, and place it in a constant temperature room for 1 to 2 hours. Preparation of A4 reference solution
Weigh a dry volumetric flask. After weighing, transfer the solution obtained in Article A3 to the volumetric flask. Add water until it is slightly less than the mass of the solution to be prepared. Weigh and drop Add a small amount of water, continue to weigh, repeat several times until the required mass is measured, and mix well. The mass of the solution is buoyantly corrected according to the formula in Appendix B of GB10738.
Calculation of A5 reference solution concentration
The reference solution concentration is calculated according to the following formula:
mi
×1000
c
m2· M
concentration of the reference solution, mol/kg;
where:——
m
m2
the first reference reagent after buoyancy correction ( The mass of the reference solution after buoyancy correction, g; M
The relative molecular mass of the first base reagent (capacity), g/mol. Additional notes:
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 Factory. This standard is drafted by Beijing Chemical Plant. The main drafters of this standard are Wang Sunjie, Chen Hua and Liu Dongni. This standard was first published in 1977.
537
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